Top 12 Repurposed Drugs and Metabolic Strategies for Cancer Treatment: Evidence Based (2024)

This is a review of the published literature showing options for natural strategies and repurposed drugs that can be used in cancer prevention and treatment. It is not intended as a stand-alone guide to treating cancer. Nothing in this document should be taken as a basis to initiate treatment without guidance or avoid any treatment prescribed by your treating physician. This information is offered as a basis to assist mutual decision-making. Cancer care should always be supervised by a healthcare provider. Patients with cancer should ALWAYS consult with their regular oncologist as well as an integrative provider/oncologist, in addition to their primary care provider.

Related: Top 10 Cancer Fighting Supplements

Diverse cancer hallmarks targeted by repurposed non-oncology drugs. This figure was created with Biorender.com. Source: Nature 2024

Many of us were first exposed to the idea of using prescription drug cocktails to treat cancer by Ben Williams. Mr. Williams was diagnosed with glioblastoma in March 1995. He availed himself of a drug and supplement protocol that proved to be effective. He chronicled these treatment choices first on a website and in his 2002 book, Surviving Terminal Cancer: Clinical Trials, Drug Cocktails, and Other Treatments Your Oncologist Won’t Tell You About. The protocol he followed stood out not just because of the many nutritional supplements but also because he took multiple off-label drugs. Williams took a range of drugs including Accutane, Actos, and Celebrex that evidence suggested might have an additive or synergistic effect against glioblastoma. 

Chemotherapy has survival advantage on 'chemotherapy curable cancers' (left column) but chemotherapy does not have survival benefit for most cancers on the right column: FLCCC Alliance

Methodology

For evidence, we include first meta-analyses of clinical trials. If these are not available, we then include individual clinical trials. If these are not available, we include case series, and then case studies. If human studies are not available, we rely on preclinical evidence.

Top Alternatives and Metabolic Interventions to Control Cancer

The Repurposing Drugs in Oncology (ReDO) project has cataloged 268 approved drugs with anticancer effects. It would be impossible to review all the drugs in ReDo’s database in this article; rather, we have focused on, curated and evaluated the drugs or natural compounds that appear to have the greatest clinical utility. These repurposed drugs are listed in priority according to the strength of the supporting clinical and mechanistic evidence. 

SUMMARY OF TOP REPURPOSED DRUGS AND METABOLIC INTERVENTIONS TO CONTROL CANCER 

List based on the quality of evidence. 

1. Avoid Ultra Processed Foods
2. Vitamin D3, Omega 3 and Cancer
3. Fenbendazole / Mebendazole / Albendazole and Cancer
4. Turmeric (Curcumin)
5. Vitamin C and E
6. Molecular Hydrogen
7. Metformin
8. Ivermectin and Cancer
9. Melatonin
10. Mistletoe
11. Aspirin and Celecoxib (COX-2 Inhibitor)
12. Statins

1. Diet and Cancer

Avoid Ultra Processed Foods

A 2024 umbrella review* (BMJ) of the literature confirmed what multiple studies have shown — the higher your intake of ultraprocessed food, the higher your risk of adverse health outcomes. The analysis, which included 45 unique pooled analyses and 9,888,373 participants, found direct associations between 32 health parameters and exposure to ultra processed food, including metabolic dysfunction, cancer, mental, respiratory, cardiovascular and gastrointestinal issues, as well as all-cause mortality.

*Umbrella review: An umbrella review, or a review of reviews, is a systematic review that only considers other systematic reviews as an eligible study type for inclusion. An umbrella review compiles evidence from multiple existing reviews and is one of the strongest and highest levels of evidence.

Another umbrella review*, published in May 2024 in PLOS One, evaluated 48 previous reviews and meta-analyses published between 2000 and 2023 and concluded that vegetarian or vegan diets “significantly reduce the risk” of ischemic heart disease, gastrointestinal cancer, and prostate cancer, as well as associated mortality.

Caution: What are the nutrients of concern for vegetarians and vegans? Vitamin B12 and K2. Anybody who is eating a vegan diet or a vegetarian diet or just a mostly plant-based diet should be taking vitamin B12 and K2 supplements. Vitamin B12 is only found in significant amounts in animal products and fortified foods, and a deficiency can cause anemia, mood changes, or permanent neurological damage. Plant-based diets may also be low in vitamin D, omega-3 fatty acids, and minerals like iodine, selenium, iron, and zinc. 

Evidence from another umbrella review (BMJ 2023) of more than 8,000 studies supports the limiting dietary sugar recommendation.

Another 2023 umbrella review (more than 100 studies analysed) of the literature indicated that a high intake of dietary fiber is associated with a reduced risk of several types of cancer, including esophageal, gastric, colon, rectal, colorectal adenoma, breast, endometrial, ovarian, renal cell, prostate, and pancreatic cancers. Conclusion: Dietary fiber intake has different protective effects on different cancers.

According to a 2019 Lancet publication, risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g.

Low-carbohydrate Diet, low glycemic index and Keto Diet

A carbohydrate-restricted diet (less than 25 g of carbs per day) that is high in saturated fat and Omega-3 fatty acids (ketogenic diet) is suggested. Avoid all processed food (see the FLCCC Guide to Fasting and Healthy Eating for more detailed guidance). Contrary to current dogma, saturated fatty acids are “healthy,” but you should avoid processed Omega-6 vegetable oils (see below). Avoid foods that are high on the glycemic index and follow the “hacks” to flatten the blood glucose curve (see below).


The saturated fat-cholesterol hoax

The Cholesterol-Saturated fatty acid hoax began to proliferate in the 1960s. Dr. Ancel Keys popularized the notion that saturated fats and high cholesterol were the primary causes of atherosclerotic heart disease — the so-called Diet-Heart Hypothesis. This concept has been vigorously studied, including in many randomized controlled trials, and has been convincingly proven to be false (BMJ 2016). Indeed, replacing saturated fats with a diet high in vegetable oils (linoleic acid) was associated with higher rates of death, cardiovascular and coronary heart disease as well as a significantly increased risk of cancer (BMJ 2013).

Healthy and unhealthy oils 

Avoid seed oils high in linoleic acid. Linoleic acid is an Omega-6 fatty acid that our bodies require in small amounts. Unfortunately, many people eat up to 10 times the desired amount of linoleic acid, because of excess consumption of foods made with seed oils. Too much linoleic acid is associated with inflammation, obesity, heart disease, and other unfavorable conditions. Therefore, avoid:

• Soybean oil 

• Corn oil 

• Cottonseed oil 

• Sunflower oil 

• Sesame oil 

• Grapeseed oil 

• Safflower oil 

• Margarine 

• Rice bran oil 

Instead, opt for healthy oils and fats such as the ones listed below. Use only high-quality products and check production and expiration dates. 

• Olive oil (oleic acid, Omega-9 monounsaturated fatty acids); never heat olive oil to the point where it produces smoke. 

• Avocado oil (oleic acid, Omega-9 monounsaturated fatty acids) 

• Coconut oil (medium chain fatty acid) 

• Flaxseed oil (alpha-linolenic acid, ALA Omega-3) 

• Walnut and Pecan oils; should be refrigerated to avoid spoilage 

• Butter (saturated fat) 

Low-Carb and Fasting Are Ill-Advised

As noted by Dr Peter Attia, weeklong fasting significantly deteriorates thyroid function, and that can be explained by the lack of nutrients during a fast. While he does not address this, the same applies to low-carb eating and time-restricted eating (TRE). All three of these strategies will activate your adrenals, trigger cortisol release and down-regulate your thyroid function and metabolism. 

So, while low-carb and various fasting regimens can be helpful in the short term to address extreme obesity, there are safer, albeit slower, ways to address that. As explained in "Important Information About Low Carb, Cortisol and Glucose", elevated cortisol is highly problematic, as it breaks down your lean muscle, bones and brain to make amino acids that your liver then converts to glucose. It also promotes inflammation and is a primary driver of aging. 

If cortisol is chronically elevated, you will likely die prematurely, as it is highly catabolic, meaning it will break down your body tissues. Cortisol is released when your body doesn’t have enough glucose available, so it’s important to eat enough healthy carbs and not deprive your body of glucose for extended periods.

Low-carb/high-fat diets ultimately backfire because they inhibit glucose metabolism, which is the most efficient form of energy production in your mitochondria; they also impair thyroid function. Your thyroid is crucial for energy production, and if your thyroid doesn't work, you're down the creek without a paddle.

One of the reasons for this is because ketogenic diets increase the stress hormones — cortisol, glucagon and adrenaline. On the other hand, one of the reasons why ketogenic and carnivore diets are usually helpful for a time is because, if implemented properly, you’re radically reducing your intake of omega-6 fats, linoleic acid (LA) in particular, which is one of the primary drivers of ill health.

 

Cautions and Concerns: Things to Consider Before Fasting

Fasting can have certain side effects, including mood swings and, notably, hunger. In today’s culture, where snacking and constant indulgence in food are common, fasting can be seen as equivalent to starvation.

Dr. Jason Fung, a nephrologist and fasting expert, however, would argue that fasting is a purposeful way of managing one’s day by allocating specific times for eating.

The benefits of fasting can vary among individuals, and the preferred type of fasting can also differ. Intermittent fasting is generally safe, but not everyone responds well to prolonged fasting.

During prolonged fasts, the body primarily breaks down fat for energy rather than muscle. However, the extent to which fat or muscle is targeted can vary based on an individual’s body composition. Those who have more fat to lose may lose more fat and less muscle, while those with higher muscle mass may experience a greater breakdown of protein stores.

Studies have shown that lean muscle mass loss occurs within the first day of prolonged fasting, regardless of an individual’s fat and muscle proportions. Therefore, individuals with significant muscle mass may experience more muscle loss and less fat loss during prolonged fasting.

There are different approaches to incorporating fasting into one’s lifestyle, such as intermittent fasting or longer fasting periods every few months. Social norms, like having dinner together, can discourage extended fasting, so it’s important to choose a fasting style that suits one’s lifestyle and preferences.

However it should be noted that intermittent fasting is not recommended for:

• Older people are notorious for getting frail very quickly if they skip even one meal. They don’t eat very often, but they need their meal. If you don’t give it to them, they can very quickly decline. 
• Extended fasting is also not a healthy long term strategy as it increases your stress hormones and worsens mitochondrial function.
• People with diabetes and kidney disease are also recommended to check with their primary care physicians before considering intermittent fasting.
• Those taking hypoglycemic or antihypertensive medication are particularly at risk, as they may end up overdosing. If you're on medication, you need to work with your doctor to ensure safety, as some medications need to be taken with food and/or can become toxic when your body chemistry normalizes. 
• People younger than the age of 18, as it can prevent growth. 
• Pregnant and breastfeeding women are also not recommended to fast intermittently. 

Credit: FLCCC 2024 Conference

2. Vitamin D3, Omega 3 and Cancer

Vitamin D can absorb calcium and help the immune, muscle, and nervous systems function properly. There are more than 11,000 search results on vitamin D and cancer on PubMed. 

A 2023 systematic review and meta-analysis of 14 RCTs (randomized controlled trials), published in Ageing Research Reviews (Kuznia 2023) found vitamin D3 supplementation reduced cancer mortality by 6%. This wasn’t considered statistically significant, but when only studies involving daily vitamin D intake were analyzed, cancer mortality dropped by a significant 12%.

The first randomized-controlled trial (DO-HEALTH) trial to investigate the combination of three complementary treatments for the prevention of cancer and suggest that the combination of daily vitamin D3, supplemental marine omega-3s, and a simple home exercise program may be effective in the prevention of invasive cancer among generally healthy and active adults aged 70 and older.

Findings from a 3 year Randomized Controlled Trial with more than 2,000 participants observed a 61% reduction in the risk of invasive cancer among patients who completed a home exercise program and took vitamin D3 and omega-3 fatty acids daily.

These results, from the DO-HEALTH trial (ClinicalTrials.gov identifier NCT01745263), were published in Frontiers in Aging 2022.

A Secondary Analysis of the VITAL Randomized Clinical Trial studied the effect of Vitamin D3 Supplements on Development of Advanced Cancer. The Harvard research, published in the JAMA Network Open medical journal (2020), overturns the initial findings of a study of 25,000 people published in 2018.

Initially researchers believed there was no benefit from taking vitamin D, as they detected no reduced incidence of cancer diagnoses overall. But they were puzzled because cancer deaths went down among those taking the supplements. Meaning, there was no benefit in terms of prevention of cancer but a reduction in cancer deaths was observed.

A secondary analysis, found this anomaly can be explained by the fact that vitamin D seems to stop metastatic cancers - those aggressive types which spread to other parts of the body. That said, when stratified by BMI (body mass index), there was no significant reduction for the vitamin D arm in incident metastatic or fatal cancer among those with overweight or obesity (BMI 25-<30).

The cancers for which the most human data are available are colorectal, breast, prostate, and pancreatic cancer. Numerous epidemiologic studies have shown that higher intake or blood levels of vitamin D are associated with a reduced risk of colorectal cancer (R). In contrast, the Women’s Health Initiative randomized trial found that healthy women who took vitamin D and calcium supplements for an average of 7 years did not have a reduced incidence of colorectal cancer (NEJM 2006). Some scientists have pointed out that the relatively low level of vitamin D supplementation (10 μg, or 400 IU, once a day), the ability of participants to take additional vitamin D on their own, and the short duration of participant follow-up in this trial might explain why no reduction in colorectal cancer risk was found. 

According to BreastCancer.org, research suggestsTrusted Source that certain cancers such as breast cancer, can have a higher risk of occurring when the body has low levels of vitamin D. 

Studies also show a link between vitamin D deficiency and cardiovascular disease, diabetes, and cancer (Sizar, 2020).

In 2016, a landmark study published in PLOS ONE found that women over 55 with blood concentrations of vitamin D higher than 40 ng/ml, had a 67% lower risk of cancer compared women with levels lower than 20 ng/ml.

Many experts now recommend 800 to 1,000 IU a day, a goal that's nearly impossible to attain without taking a supplement. Although protection is far from proven, evidence suggests that vitamin D may help reduce the risk of prostate cancer, colon cancer, and other malignancies. 

Types of cancers that Vitamin D may be beneficial for 

Vitamin D supplementation is likely beneficial in most cancers, but particularly in patients with breast, colorectal, gastric, esophagus, lung, and prostate cancer as well as those with lymphomas and melanoma. 

Although the role of vitamin D in cancer prevention remains an area of research interest and debate, avoiding deficient levels is recommended. (American Cancer Society 2020)

Vitamin D can also be absorbed through sunlight, or with the following diet: 

• fatty fish 
• egg yolks 
• fortified milk

Make sure to take 500 mg to 1000 mg of magnesium and 150 mcg of vitamin K2, (not K1) which are important cofactors for optimizing vitamin D function. And, remember the only way you know what your vitamin D level is, is to test it. Vitamin D level should be in a therapeutic range of 50 to 70 ng/ml for treatment of rheumatoid arthritis. Most people are shocked how low their level is when they finally get around to testing it.

Related: Vitamin D Level and Cancer: Vitamin D Reduces Cancer Deaths

Vitamin D and Chemotherapy

Multiple studies indicate that a significant proportion of cancer patients are vitamin D-deficient (level < 20 ng/mL) and that higher plasma 25-hydroxyvitamin D levels are associated with improved survival in colorectal, breast, gastric, and lymphoma cancer patients [Systematic Review 2014]. Meta-analyses and clinical trials demonstrate that vitamin D supplementation may reduce cancer mortality and improve survival in cancer patients, especially when used in combination with chemotherapy (Meta-analysis 2023). SUNSHINE (JAMA 2019), a clinical trial on metastatic colorectal cancer patients, showed that “high-dose” vitamin D3 (aiming for a level of >50 ng/mL) combined with standard chemotherapy resulted in improved progression-free survival compared to standard-dose vitamin D3.

3. Turmeric (Curcumin) and Cancer

There are more than 8,000 search results on curcumin and cancer on PubMed and more than 50 clinical trials with curcumin, most of which are still ongoing. The spice turmeric can be extremely helpful when it comes to fighting cancer. 

Studies show that the curcumin in turmeric may kill cancer cells and slow tumor growth. This preclinical research has taken curcumin from the lab to the clinic. 

The benefits of curcumin may include: 

• blocking cancer cells from multiplying
• killing colon, breast, prostate, and melanoma cancer cells
• slowing tumor growth

Most of the studies published on PubMed are non-human (pre-clinical) studies. 

A review paper published in 2022, analysed 21 human studies. Sixteen out of 21 clinical trials were associated with the effectiveness of curcumin or turmeric on various types of cancer, and the other five clinical trials were related to the evaluation of the efficacy of curcumin or turmeric in relieving the side effects of cancer chemotherapy and radiotherapy. The emerging data from the clinical trials confirm that curcumin has the potential for cancer prevention and intervention. 

Significantly, the active elements in curcumin attack cancer while leaving healthy cells untouched. For the purpose of disease intervention, while turmeric is available in powdered form, it contains very little of the active compounds in curcumin, or only about a 3% curcumin concentration.

Because it's not easily absorbed through your gastrointestinal tract, it's more effective to use a high-quality bioavailable curcumin extract, according to a 2013 study. A typical anticancer dose is just under 1 teaspoon of curcumin extract three or four times daily.

Both curcuminoids and related turmeric products have been sanctioned by the U.S. Food and Drug Administration (FDA) as safe.

Turmeric and black pepper each have health benefits, due to the compounds curcumin and piperine. As piperine enhances curcumin absorption in the body by up to 2,000%, combining the spices magnifies their effects. (Healthline)

The use of fenbendazole and curcumin, has achieved much attention due to the reported experience of Joe Tippens. In 2016, Tippens was diagnosed with non-small-cell lung cancer with extensive metastatic disease. At the advice of a veterinarian friend, he took Fenbendazole together with nanocurcumin, and three months after starting these drugs his PET scan was completely clear. He remains alive and disease-free up until the present.

                      

4. Fenbendazole / Mebendazole / Albendazole and Cancer

A search on PubMed for “benzimidazole AND cancer” yielded more than 8,000 citations. 

The use of benzimidazoles in cancer is limited to a few case reports and a small case series (Chiang 2021). Mebendazole (MBZ) is a component of the multidrug cocktail used in the METRICS study (Agrawal 2019).  The use of benzimidazoles, and in particular fenbendazole, has achieved much attention as a repurposed drug for cancer due to the reported experience of Joe Tippens. In 2016, Tippens was diagnosed with non-small-cell lung cancer with extensive metastatic disease. At the advice of a veterinarian friend, he took Fenbendazole together with nanocurcumin, and three months after starting these drugs his PET scan was completely clear. He remains alive and disease-free up until the present.

Types of cancers that mebendazole may be beneficial for 

A wide variety of cancers, including NSCLC (non small cell lung cancer), adrenocortical, colorectal, chemo-resistant melanoma, glioblastoma multiforme, colon, leukemia, osteosarcoma/soft tissue sarcoma, acute myeloid sarcoma, breast (ER+ invasive ductal), kidney, and ovarian carcinoma, have been shown to be responsive to benzimidazoles, including MBZ. (Guerini 2019, Meco 2023) 

Dosing and cautions 

We suggest Mebendazole 100-200 mg/day. The cost of mebendazole in the U.S. skyrocketed once this drug was discovered to have activity against cancer ($555 for a single 100 mg tablet). However, mebendazole is available from international compounding pharmacies (India) at about 27c for a 100 mg tablet. 

Read More: Fenbendazole Cancer Success Stories and Treatment Testimonials: Case Series

5. Metformin

A search on PubMed for “metformin AND cancer” yielded more than 7,000 citations. 

Numerous trials have shown that metformin, routinely used to treat diabetes, also inhibits the development of cancer cells and reduces cancer cell proliferation. Unlike most standard chemotherapy, metformin suppresses cancer stem cells, the root of cancer. (Shi 2017)

Many cancer patients also have type-2 diabetes. Yet few take metformin because treating diabetes has taken a backseat to treating their cancer. We check hemoglobin A1c status on all our cancer patients. The medical standard of care is to prescribe metformin for anyone with a 5.8% or higher A1c. 

Clinical studies 

The results of the Taiwan National Health Insurance Data Survey (2019), which included a community of 12,005 patients taking metformin from 2000 to 2007 and a population of 4,597 patients taking other oral medications, indicated that using metformin reduces the chance of any type of cancer up to 88%.

Meta-analyses have examined the role of metformin in the primary prevention of cancer, where it was found to significantly reduce overall cancer incidence (Gandini 2014). Lega et al (2014) performed a meta-analysis of 21 observational studies, evaluating the outcomes of diabetic patients with cancer who were receiving metformin. In this study, metformin was associated with a reduction in all-cause mortality and cancer-specific mortality; patients with colorectal cancer demonstrated the greatest benefit. 

In a similar analysis performed by Yin et al (2013), metformin improved overall survival in patients with lung, breast, and prostate cancer. 

Coyle et al (2016) performed a meta-analysis of 27 observational studies which investigated the use of metformin as an adjunctive treatment for cancer. The findings of this study suggested that metformin was associated with significant benefit in the early treatment of patients with colorectal and prostate cancer, particularly in those receiving radical radiotherapy. 

Types of cancers that metformin may be beneficial for 

A 2023 meta-analysis revealed a 45% risk reduction in thyroid cancer among metformin users in Eastern countries, a phenomenon which was more evident in Asian populations than their Western counterparts.

Another extensive 2022 meta-analysis ascertained a notably lower gynecological cancer occurrence in those undergoing metformin treatment compared to alternative therapies (gynecological cancer: HR = 0.60, 95% CI: 0.49–0.74; endometrial cancer: HR = 0.65, 95% CI: 0.50–0.85; ovarian cancer: HR = 0.47, 95% CI: 0.27–0.82).

Various malignancies can be prevented with the use of metformin. In general, metformin can: i) lower cancer incidence, ii) lower cancer mortality, iii) improve cancer cell response to radiotherapy and chemotherapy, iv) optimize tumor migration and lower malignancy, v) lower relapse risk, and vi) lessen the harmful effects of androgen derivatives. (Saraei 2019)

Collective findings show that metformin has a broad spectrum of anticancer activity against breast, pancreatic, gastric, colorectal, endometrial, pancreatic prostate, non-small cell lung cancer (NSCLC), and bladder cancers. (Buczyńska 2022, Stopsack 2016, Mei 2014) However, the greatest benefit may be in patients with colorectal and prostate cancer, (Stopsack 2016, Mei 2014), particularly when used as an adjunctive therapy.

Dosing and cautions 

A dose of metformin of 1,000 mg twice daily is suggested. Metformin is a remarkably safe drug with very few side effects. The most common adverse effects include abdominal or stomach discomfort, cough, hoarseness, decreased appetite, and diarrhea. Prolonged use is associated with vitamin B12 deficiency; supplementation with a B complex vitamin is therefore suggested. Metformin may cause very low blood glucose when combined with berberine; hence the blood glucose should be very closely monitored in patients taking this combination; if low glucose does occur, we would suggest alternating metformin and berberine (monthly). 

Note: Preclinical, epidemiological, and clinical insights have confirmed that metformin may act as a metabolic modulator by targeting various molecular pathways. Thus, metformin is a promising potent adjunct in anticancer regimens that could potentially synergize with chemotherapy, targeted agents, and immunomodulators.

6. Vitamin C and E

PubMed has indexed more than 3,000 research studies on vitamin C and cancer and more than 5,000 studies on vitamin E and cancer.

Prevention

2022 - An umbrella review* (Xu 2022) to assess the existing systematic reviews and meta-analyses for the association between vitamin C intake and multiple health outcomes; showed that vitamin C intake was associated with reduced risk of all-cause mortality, cardiovascular disease (CVD), oesophageal cancer, gastric cancer, cervical cancer and lung cancer with an increment of 50–100 mg per day.

Beneficial associations were also identified for respiratory, neurological, ophthalmologic, musculoskeletal, renal and dental outcomes. A total of 76 meta-analyses (51 papers) of randomised controlled trials and observational studies with 63 unique health outcomes were identified. Harmful associations were found for breast cancer and kidney stones for vitamin C supplement intake. 

*Umbrella review: An umbrella review, or a review of reviews, is a systematic review that only considers other systematic reviews as an eligible study type for inclusion.

2022 - Obese women who took vitamin C and B6 at amounts that exceeded the recommended daily intake levels were associated with a lower risk of breast cancer, according to a five-year long South Korean cohort study. 40,432 women without a history of cancer at baseline were included in this study.

2022 - A meta-analysis to review the association between vitamins and brain cancer showed that intake of vitamin C, β-carotene, and folate can reduce the risk of brain cancer, while high serum α-tocopherol (vitamin E) concentration also has a protective effect on brain cancer.

Treatment

2022 - A systematic review on the effect of vitamins C and E on cancer survival showed improvement of survival and progression rates of cancers by vitamins C and E. However, the authors concluded that more high quality trials with large sample sizes are required to confirm.

Vitamin C is known as an antioxidant, but at high concentrations, vitamin C can kill cancer cells through a pro-oxidant property (Transl Oncol. 2020). This study has also demonstrated that vitamin C treatment with magnesium supplementation provided more effective anticancer therapy than vitamin C treatment alone.

High-dose vitamin C cancer therapy was introduced by Linus Pauling and Ewan Cameron [R]. Clinical demonstration results by Pauling and Cameron showed that intravenous injection of 10 g/day of vitamin C extended the survival time of terminal cancer patients by about 4.2 times. However, results from the Mayo Clinic in 1979 showed that the survival time of vitamin C–treated patients was even shorter than that of the placebo group patients [R]. A significant difference between those two research groups was the route of AA administration: intravenous injection and oral administration, respectively. 

To understand the mechanism of AA's anticancer activity, many research groups have treated colon, prostate, leukemia, lymphoma, brain, and stomach cancer cells and chemically or genetically transformed cancer cells with AA and showed cancer growth inhibition and even cancer cell death through hydrogen peroxide–mediated reactive oxygen species (ROS) generation [R]. In most cases, the pharmacological concentration of vitamin C required for anticancer effects (EC50 value of 1–10 mM) could only be achieved by intravenous administration. Thus, to apply vitamin C as an anticancer therapy, a high intracellular concentration in cancer cells is critically important (R).

Vitamin C and Aspirin

In laboratory tests, the aspirin-vitamin C combination showed a strong cytotoxic effect on liver cancer cells but was much less harmful to normal lung cells. This selectivity is crucial for reducing the side effects associated with cancer treatments. The synergy between these two common substances appears to enhance their individual anticancer properties, offering a safer alternative to harsh chemotherapies.

The potential of aspirin and vitamin C extends beyond the lab, with encouraging results in animal studies. When tested on rats with chemically induced liver cancer, the combination therapy showed remarkable results. After 90 days of treatment, the livers of treated rats had significant improvement in both appearance and function.

In another study, the combination of aspirin, also known as acetylsalicylic acid (ASA), and vitamin C, or ascorbate (AS), showed superior results in shrinking tumors compared to either compound alone. When mice with solid tumors were treated with the combination, their tumor volume decreased by 46%, versus 40% with ASA alone and 36% with AS alone.

This synergistic effect likely stems from combining aspirin's anti-inflammatory properties with vitamin C’s potent antioxidant capabilities. The two compounds appear to work together to create a more hostile environment for cancer cells, impeding their growth and proliferation.

By attacking tumors through multiple mechanisms simultaneously, the aspirin-vitamin C combination may overcome some of the adaptations cancer cells typically develop to evade single-compound treatments.

Beyond just shrinking tumors, the aspirin-vitamin C combination significantly extended survival times and appeared to improve overall health in the tumor-bearing mice. Mice treated with the combination survived an average of 93.5 days, compared to just 54 days for untreated tumor-bearing mice — a 73% increase in lifespan.

Related: Benefits of High Dose Vitamin C in Cancer Treatment

7. Molecular Hydrogen and Cancer

In terms of cancer management or treatment, studies involving the effects of H2 on cancer were systematically reviewed. More than 600 articles related to molecular hydrogen and cancer were retrieved from Cochrane, PubMed and Google Scholar, and 27 articles were included for this systematic review (2023). 

Based on the authors' analysis, "H2 plays a promising therapeutic role as an independent therapy as well as an adjuvant in combination therapy, resulting in an overall improvement in survivability, quality of life, blood parameters, and tumour reduction."

Although H2 has demonstrated significant anti-cancer effects, the underlying mechanisms have not yet been elucidated. Many studies have shown that H2 therapy can reduce oxidative stress. This, however, contradicts radiation therapy and chemotherapy, in which ROS (Reactive Oxygen Species) are required to induce apoptosis and combat cancer. 

Related: Best Molecular Hydrogen Tablets

Note: Most Molecular Hydrogen tablets uses pure elemental magnesium as its carrier and provides you with approximately 80 mg of magnesium per tablet. So, you receive also highly bioavailable magnesium for a healthy brain, muscles, cells, kidneys, and heart.

8. Melatonin

PubMed has indexed more than 3,000 research studies on melatonin and cancer.

Melatonin is one of the most important antioxidant molecules. In the human body — aside from having direct antioxidant effects — it also stimulates the synthesis of glutathione and other important antioxidants like superoxide dismutase and catalase.

Many people are not aware that only 5% of your body’s melatonin — which is also a potent anticancer agent — is produced in your pineal gland. The other 95% is produced inside your mitochondria — provided you get sufficient near infrared exposure which is typically from sun on your bare skin. This is why vitamin D is more than likely a biomarker for sun exposure, which is intricately involved in melatonin production. (R)

Melatonin - Treatment

2022 - An umbrella review of meta-analyses based on randomized controlled trials (Pharmacological Research 2022):

"Survival at one year (P < 0.005) significantly increased with cancer patients."

2020 - A case series of 14 advanced cancer patients (Trends in Oncology 2020), treated with high dose (1,000 mg/day) of melatonin; achieved a disease control of 54% of the patients:

"Moreover, this preliminary study may also suggest that high dose melatonin has no toxicity in cancer patients with poor clinical status, as well as in healthy subjects."

9. Ivermectin and Cancer

In a 2021 review paper, the related mechanisms by which ivermectin inhibited the development of different cancers and promoted programmed cell death were discussed. Also reviewed was the prospects for the clinical application of ivermectin as an anticancer drug for cancer therapy.

In another study, published in Nature (2021), Ivermectin stimulates T-cells to invade and destroy tumors and synergizes with immune checkpoint blockade for treatment of breast cancer.

Clinical studies 

While many in vitro studies have demonstrated the effectiveness of ivermectin against multiple cancers, the clinical effectiveness is limited to small case series. (De Castro 2020, Ishiguro 2022)

Dosing and cautions 

The optimal dosing strategy with ivermectin is unclear. De Castro et al reported the use of 1mg/kg/day for up to 6 months in three pediatric patients with refractory AML without untoward side effects (De Castro 2020). Ishiguro et al reported the use of ivermectin 12 mg twice weekly. (Ishiguro 2022) 

Read More: Ivermectin Cancer Success Stories: Case Series (2024)

10. Mistletoe

Over 50 prospective studies (2020), including more than 30 randomized controlled trials (RCTs), have investigated the role of mistletoe in cancer patients, showing benefits in terms of improved quality of life, performance index, symptom scales, and reduced adverse effects of chemotherapy.

Another 2022 review has further supported these findings, revealing that mistletoe extracts significantly improve global quality of life and may have a favorable effect on survival in cancer patients (HR = 0.81, 95% CI 0.69–0.95, p = 0.01) when used as in combination to conventional treatments.

A phase I trial (2023) of intravenous mistletoe extract in patients with advanced cancer showed a disease control rate of 23.8% and improved quality of life indicators. Mistletoe is commonly used by integrative oncologists to enhance quality of life, increase chemotherapy tolerability, and potentially contribute to better tumor control and survival.

11. Aspirin and Celecoxib (Celebrex)

Aspirin and Cancer

In November 2023, researchers from Cardiff University in the United Kingdom published a comprehensive review in the British Journal of Cancer (BJC) outlining aspirin’s potential to reduce cancer mortality, prevent metastatic cancer spread, and minimize vascular complications. The review encompassed both favorable and unfavorable evidence, thoroughly analyzing the rationale behind using aspirin in cancer treatment.

The study compiled results from 118 observational studies involving approximately 1 million cancer patients. It revealed that daily intake of low-dose aspirin (75 or 81 milligrams) was associated with a 21 percent reduction in all-cause mortality.

Read more: Aspirin Inhibits Metastatic Cancer Spread, Reducing Mortality by 21 Percent: Study

A study involving pancreatic cancer patients undergoing surgery indicated that patients who took aspirin had a three-year survival rate of 61.1 percent, compared to 26.3 percent for those who did not take it.

A comprehensive review published in the renowned journal Annals of Oncology in 2020 indicated that patients who take aspirin have a relatively lower risk of developing various types of cancer.

The researchers conducted a comprehensive analysis of all observational studies on aspirin and digestive tract cancers published until March 2019, encompassing over 150,000 cases. The results revealed that, compared to patients not using aspirin, those who regularly took aspirin had a 27 percent reduced risk of colorectal cancer, a 33 percent reduced risk of squamous cell esophageal cancer, a 39 percent reduced risk of adenocarcinoma of the esophagus and gastric cardia, a 36 percent reduced risk of stomach cancer, a 38 percent reduced risk of hepatobiliary tract cancer, and a 22 percent reduced risk of pancreatic cancer. However, there was no significant change in the risk of head and neck cancer.

For colorectal cancer, taking a daily dose of aspirin between 75 and 100 milligrams can reduce the risk by 10 percent, while a daily dose of 325 milligrams can reduce the risk by 35 percent.

As covered above (under vitamin C and aspirin), various pre-clinical studies have showed the potential of aspirin and vitamin C with encouraging results in animal studies.

Celecoxib (Celebrex) and Cancer

Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is conventionally prescribed for adult arthritis. However, recent studies have described the anticancer properties of celecoxib, which are mediated through the suppression of COX-2, a factor that is closely associated with cancer-related inflammation by promoting the synthesis of various prostaglandins, such as prostaglandin E2 (PGE2). (source)

Mr. Ben Williams was diagnosed with glioblastoma in March 1995. He availed himself of a drug and supplement protocol that proved to be effective. He chronicled these treatment choices first on a website and in his 2002 book, Surviving Terminal Cancer: Clinical Trials, Drug Cocktails, and Other Treatments Your Oncologist Won’t Tell You About. The protocol he followed stood out not just because of the many nutritional supplements but also because he took multiple off-label drugs. Williams took a range of drugs including Accutane, Actos, and Celebrex that evidence suggested might have an additive or synergistic effect against glioblastoma. 

 

A compelling study by Guo et al. demonstrated that administration of celecoxib post-diagnosis led to better overall survival rates in cancer patients, particularly those exhibiting positive PTGS2 expression combined with a phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutation.

Overall, the momentum of clinical trials investigating the role of celecoxib in cancer therapy is intensifying. In particular, the potential synergistic combination of celecoxib with chemotherapy or immunotherapy could improve cancer treatment outcomes, and confirm the importance of modulating inflammation as a potential therapeutic strategy against cancer.

12. Statins

Statins lower circulating blood lipids including low-density lipoprotein (LDL) cholesterol through the competitive inhibition of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR), an enzyme that facilitates the conversion of HMG-CoA to mevalonic acid, which is a crucial step in cholesterol biosynthesis. By inhibiting this process, statins not only reduce cholesterol production but also impact by-products essential for cancer cell growth, thereby demonstrating their potential as anticancer agents (source).

Of the statins, simvastatin is particularly interesting due to its anticancer applications, which have been observed in various cancer types and are largely mediated through activation of mutant P53. 

Ongoing clinical trials are currently examining the efficacy of simvastatin against various cancers, including breast (NCT00807950, NCT05550415), gastric (NCT01099085, NCT03086291), colorectal (NCT01238094), and bladder (NCT02360618) cancer. Although the specifics of its mechanism, optimal dosage, and compatibility with other anticancer drugs remain unclear, we anticipate the emergence of novel strategies employing statins in cancer treatment in the future.

Notes and Disclaimers: 

• Please do not consider this guide as personal medical advice, but as a recommendation for use by professional providers. Consult with your doctor and discuss with her/him. 
• Our aim here isn't to replace your doctors' advice. It is intended as a sharing of knowledge and information. Do take note that most treatments are not 100% protective or curative against cancer. It's a continuous struggle between the immune system and the cancer cells. Cancer treatments are meant to assist the immune system in this battle.
• Cancer treatment should be part of a multi-modal approach in order to provide the best possible outcome. Diet and lifestyle changes are also meant to run alongside conventional treatment. That said, there is no miracle treatment that can cure all cancers.

Sources and References:

• Repurposed Drugs for Cancer (Townsend Letter)

• Drug repurposing for cancer therapy (Nature 2024)

• THE ROLE OF REPURPOSED DRUGS AND METABOLIC INTERVENTIONS IN TREATING CANCER (FLCCC)

• Cancer Metabolism as a Therapeutic Target and Review of Interventions (Nutrients 2023)

• FLCCC Guide to Fasting and Healthy Eating

For more information on treatment, causes and prevention, screening, and the latest research, check out this comprehensive resource page (by cancer type) from National Cancer Institute: https://www.cancer.gov/types.

Read More: This article is part of the Winning the War on Cancer series.

Related: 

• Best Anti Cancer Supplements

• What are the Best Cancer Fighting Foods

• Benefits of Vitamin C in Cancer Treatment

• CAR-T vs CAR-NK - The Cancer Cell Therapy Showdown

10 Alternative Cancer Therapies Worth Considering for an Integrative Treatment Plan (credit: briomedical)