Cancer Expert MD

Insulin potentiation therapy, or IPT, gives a small dose of insulin through a vein and then, once blood sugar begins to fall, gives chemotherapy at a fraction of the usual dose, typically 10 to 25 percent. The idea is that insulin makes cancer cells take up more of the drug, so a lower dose can still act on the cancer while causing fewer side effects. The method was developed in Mexico by Dr. Donato Pérez García in the 1930s and is now offered by integrative physicians in the United States, Mexico and Europe, sometimes under the name IPTLD, for insulin potentiation targeted low-dose therapy. This article explains how IPT is thought to work, what the human studies show, how it differs from other low-dose chemotherapy, and the safety points to know.

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How IPT Is Thought to Work

Many cancer cells carry more receptors for insulin and for the related growth hormone IGF-1 than normal cells do. Insulin binding to those receptors has two effects that could matter for chemotherapy. It can increase how much drug enters the cell, and it can push more cancer cells into the dividing phase of their cycle, the phase in which many chemotherapy drugs work best. In a laboratory study published in 1981, insulin greatly increased the killing effect of the chemotherapy drug methotrexate on human breast cancer cells.¹

The connection to cancer metabolism is direct. Cancer cells depend heavily on sugar, as our article on the Warburg effect explains, and IPT uses the brief drop in blood sugar after insulin as the moment to give the chemotherapy. Glucose is then given to bring the blood sugar back up.

What the Human Studies Show

The randomized breast cancer study from Uruguay. Researchers studied 30 women with metastatic breast cancer that had stopped responding to standard chemotherapy and hormone therapy. They were divided into three groups of ten: insulin with methotrexate, methotrexate alone, or insulin alone. Tumor growth was significantly lower with insulin plus methotrexate than with either one alone, and insulin by itself did not make the tumors grow faster.²

The Bulgarian experience. Physicians in Sofia have published the largest series. In 196 patients with a range of cancers treated over three years, IPT was tolerated without serious side effects.³ In 16 men with castration-resistant prostate cancer treated with IPT alongside hormone therapy, the PSA fell partially in half, held stable in a quarter and rose in a quarter after six treatments.⁴ Our article on castration-resistant prostate cancer covers the other treatments for that stage.

What is still missing. These studies are small, and no randomized trial has yet compared IPT with standard-dose chemotherapy for survival. A planned quality-of-life study registered in the United States was withdrawn before it began. IPT therefore rests on laboratory research, one small randomized study and clinical experience.

IPT, Metronomic and Fractionated Chemotherapy

Several approaches use lower or divided doses of chemotherapy, and the names are often confused. Fractionated chemotherapy splits a dose into smaller amounts given more often. Metronomic chemotherapy gives low doses continuously, often as daily pills, to starve tumor blood vessels and free the immune system, and it has the strongest randomized evidence of the low-dose approaches, from trials in China, India and the Netherlands. IPT adds insulin before each low dose. Our article on metronomic chemotherapy explains that research in detail.

Safety Points to Know

Low blood sugar. The insulin is meant to lower blood sugar, so treatment must be given in a clinic with close monitoring and glucose ready. People with diabetes need special care with timing and dosing.

Chemotherapy is still chemotherapy. Side effects are usually milder at lower doses, but blood counts, nerves and organs still need monitoring.

The dose question. Reviewers have raised two theoretical concerns: that insulin and IGF-1 signaling can promote cancer growth, and that very low doses could allow resistance to develop. IPT is generally considered when the goal is long-term control, or when standard doses cannot be tolerated. Where standard-dose treatment offers a realistic chance of cure, the dose matters, and that should weigh in the decision.

Choosing the drugs. Some practitioners select the drugs for IPT using blood tests that test cancer cells against chemotherapy, such as the RGCC test or other chemosensitivity testing.

The insulin and chemotherapy drugs used in IPT are approved medicines, but their combination in this way is off-label, and IPT is generally not covered by insurance. Whether IPT fits a particular situation depends on the type and stage of cancer, the goals of treatment and the other options available. In a consultation, Dr. Silver, MD, educates you on IPT, metronomic chemotherapy and the other options, and the research behind each.

How Cancer Expert MD Helps

Cancer Expert MD provides education and consultation for people with every type and stage of cancer, and specializes in Stage IV and metastatic cancer. Our book, The New Reality of Cancer, covers low-dose chemotherapy approaches and the integrative therapies used alongside them. See also our guide to integrative cancer treatment options.

Frequently Asked Questions

What is insulin potentiation therapy?

A treatment that gives insulin through a vein followed by chemotherapy at a fraction of the usual dose, on the idea that insulin helps cancer cells take up more of the drug.

Is IPT the same as low-dose chemotherapy?

IPT is one form of low-dose chemotherapy. Metronomic and fractionated chemotherapy are others, and they do not use insulin.

What does the research show for IPT?

Laboratory studies, one small randomized study in metastatic breast cancer that favored insulin plus methotrexate, and published experience from Bulgaria. Randomized trials comparing IPT with standard chemotherapy for survival have not yet been done.

Is IPT safe?

In the published series it was well tolerated. The main risk is low blood sugar, which is why it must be given with close monitoring, and the usual chemotherapy precautions still apply.

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References

1. Alabaster O, Vonderhaar BK, Shafie SM. Metabolic modification by insulin enhances methotrexate cytotoxicity in MCF-7 human breast cancer cells. European Journal of Cancer and Clinical Oncology. 1981;17(11):1223–1228.
2. Lasalvia-Prisco E, Cucchi S, Vázquez J, et al. Insulin-induced enhancement of antitumoral response to methotrexate in breast cancer patients. Cancer Chemotherapy and Pharmacology. 2004;53(3):220–224.
3. Damyanov C, Gerasimova DM, Avramov LA, Maslev IK. Insulin potentiation therapy in the treatment of malignant neoplastic diseases: a three year study. Journal of Cancer Science and Therapy. 2012;4(4).
4. Damyanov C, Gerasimova D, Maslev I, Gavrilov V. Low-dose chemotherapy with insulin (insulin potentiation therapy) in combination with hormone therapy for treatment of castration-resistant prostate cancer. ISRN Urology. 2012;2012:140182.

This article is for education only. It is not medical advice and does not diagnose or treat any condition. Cancer Expert MD has no financial relationship with any laboratory, drug maker, supplement company, clinic or hospital.