|cancer and hiv meds
Mar 11, 2004
Dr Dr Lee can you tell me if there are any HIV meds that may be known to cause any kind of cancer. thank you
| Response from Dr. Lee
Cancer is an abnormality of cellular development. Like the term cat, the term cancer covers a lot of ferocious and very scary types (Lions, Tigers, etc.) and some types which are far less ferocious and certainly less scary (lap cats). So, each type of cancer which may be associated with some of the antiretroviral medicines, needs to be evaluated for how serious it may be.
Carcinogenesis, Mutagenesis, and Teratogenesis are related concepts which are looked at through a variety of tests performed and monitored by the FDA. It is sometimes difficult to interpret the results because the predictive capacity for humans of studies done on rodents, dogs or other biologic systems has not been clearly established.
Some substances are tested directly on tissue to see if they result in abnormal cell growth. This is "Carcinogenicity" (how likely a substance is to result in formation of abnormal or cancerous cells).
Mutagenicity is either "Genotoxicity" (how much a substance affects the rate of mutations in the DNA from what is found in normal circumstances) or "Clastogenicity" (how much a substance may cause an increase in chromosomal breakage which also results in mutations). All substances which test positive as genotoxic, clastogenic or otherwise mutagenic are considered to be cancer causing.
Teratogenicity is the association of a substance with abnormalities in fetal development. The testing for teratogenicity is similar to that for carcinogenicity but looking for developmental abnormalities.
These tests are used to determine the likelihood that a chemical compound will increase the mutations or chromosome abnormalities in human cells. Mutations occur naturally, but some substances may cause an increased rate or frequency of mutations. It is thought that genetic mutations which occur today can be associated with the development of cancer in five to ten years. There are several tests which are used to study the mutational changes in various cell types (including everything from bacterial cells to mammalian cells).
A substance which has a high likelihood of causing gene or chromosomal damage would be unlikely to receive FDA approval unless genotoxicity or clastotoxicity was considered either 1) a necessary part of the mechanism of action of the medication (such as some cancer therapies which try to disrupt the growth and development of cancer cells) or 2) outweighed by other benefits of the therapy.
Each of the medications prescribed for HIV have had some level of testing for carcinogenicity. Although some of the medicines have been associated with "benign" cellular changes at usual doseage levels, most have not been associated with the actual development of cancer. Many compounds can cause cancer at very high doses and so at times the reports will indicate the level (such as 4 times the typical human exposure) and/or the length of exposure time (such as 500 days)
Almost all of the antiretroviral medications include something like this in the package insert: "Long-term carcinogenicity studies have not been completed,... are in progress, or ... are underway." And most will also assert something similar to this: "Studies to date have not indicated... or there were no statistically significant increases... or only at high doses (in excess of four times human therapeutic levels) was in the incidence of malignant changes found to increase."
There are some which have been associated with malignant changes in high doses. There are others that have not had any REPORTED potential for malignancies, (which may simply mean that the tests that would show those malignancies have not yet been conducted).
There are now 21 drugs which have been approved to treat HIV. They all have some level at which they can cause cellular, genetic or chromosomal changes. But, that level may be 400 times the normal doses, or take sixty years to cause damage. You can look up each drug and read the specifics about them by either going to the library (check out the Physician's Desk Reference.)or getting on-line. (Try google with the name of the drug.)
To answer your specific question: are any HIV meds known to cause any kind of cancer? YES, almost all of them (In fact almost all medicines, herbal remedies, etc. can cause cancers, alhough usually at extremely high doses.)
I suggest that you sit down with your doctor and review the specifics of each of the medicines you are taking.
Get Email Notifications When This Forum Updates or Subscribe With RSS
This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.
Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither TheBody.com nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.