Rapamycin - skin cancer

On the leaflet enclosed with Rapamune in Europe, there is a warning about the risk of skin cancer. Is the risk actually as high as Pfizer reports when taking this medication?

Does the same warning appear on the leaflet enclosed in other countries as well?

Rapamune, Pfizer Europe

Warnings and precautions. Due to an increased risk of skin cancer, exposure to sunlight and UV radiation should be limited by covering the skin with clothing and using sunscreen products with a high level of protection.

Common: may affect up to 1 in 10 people

  • skin cancer


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I would take it with a grain of salt. Pharmaceutical industry must protect itself against potential lawsuits so I guess they really list any possible side effect…
Rapamycin is used in treating melanoma. If I am not mistaken studies also show that people using rapamycin after transplant have reduced risk of skin cancer if anything…


The same warning is given here in the US and it would be wrong to take it with a grain of salt. Direct sun exposure has to be limited.


But it has to be limited anyway… sun exposure is a mayor factor in aging of the skin and developing skin cancer. I think 2/3 of us will develop some sort of precancerous or cancerous changes in skin cells during our lifetime due to sun exposure.
or do you think rapamycin really increases the risk of skin cancers?

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I have never paid attention to it with other medications. However, here I read the leaflet carefully and I was surprised that the risk of cancer was estimated at 1 in 10.

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or do you think rapamycin really increases the risk of skin cancers?

No, I don’t. This is way I was even more surprised.

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An apparent reason for the high incidence of skin cancer likely relates to suppression of immune surveillance mechanisms, but other more direct effects of certain immunosuppressive drugs are also bound to contribute to cancers of UV-exposed skin. However, over the past few years, evidence has emerged to suggest that one class of immunosuppressants, mammalian target of rapamycin (mTOR) inhibitors, could potentially inhibit skin tumour formation through a number of mechanisms that are still being studied intensively today. Therefore, in light of the high skin cancer incidence in transplant recipients, it follows that clinical trials have been conducted to determine if mTOR inhibitors can significantly reduce these post-transplant skin malignancies.


Rapamycin has had the opposite effect on me. I have had chronic actinic keratosis for decades and two basil cell carcinomas removed. Since I started rapamycin my skin is free from actinic keratoses. I used to go to my dermatologist at least twice a year for treatment. Now I haven’t seen a dermatologist for two years. My extreme exposure to sunlight, when I was young, was the cause of the keratosis so I no longer expose myself to the sun whenever possible.