Welcome to this installment of The AIDS Pandemic, a podcast hosted by Dr. David Wessner from the Department of Biology at Davidson College. I’m Mike Neri.
In this episode, I will talk about a topic that is gaining increasing interest from the AIDS community: cancer. This podcast goes over why cancer is becoming more of an issue for AIDS patients, why some cancers occur more often in HIV-positive people, the complications of treating people with AIDS for cancer, and what needs to be done in the fight against cancer and AIDS.
Most people following the evolution treatment of AIDS patients focus on the development of more effective drugs against HIV as the main battle in the war against this disease. Certainly, finding medicines that can lessen HIV’s ability to destroy the immune system and function inside the body is critical to making progress in the treatment of this pandemic. However, many people don’t realize that prolonging the lives and improving the quality of life for people with AIDS is not the end of fight. In fact, newer drugs can often complicate treatment of other diseases later on down the road and contribute to more health issues as AIDS patients get older.
Cancer is one of the best examples of the problems that people with AIDS face even after their medication has allowed them to live a somewhat normal life. It is well known that as a person ages, his or her susceptibility to cancer increases. This is no exception in AIDS patients, and as more patients survive longer due to new medicines, cancer and cancer treatment of the immunosuppressed of the AIDS community will continue to become a bigger issue.
In the public eye, cancers are not normally associated with immunodeficiency or infectious particles, but rather with carcinogens, heredity, and genetic mutations. However, cancer statistics show that viruses are responsible for as many as 15% of cancers in humans, not to mention other infectious particles like bacteria that have been linked to some cancers. This fact may help to explain the increased occurrences of some cancers in the immunosuppressed of the AIDS community.
Certain types of cancers have been associated with AIDS since the first cases of the disease. In these early days of the pandemic, a very rare cancer called Kaposi’s sarcoma was often a tell-tale sign of AIDS, and thus became known as an AIDS-defining cancer. Some other AIDS-defining cancers were non-Hodgkin’s lymphoma and cervical cancer, both of which are associated with viruses (as is Kaposi’s sarcoma) and took advantage of a host’s decreased immune defenses. In contract, non-AIDS-defining cancers are those not associated with immunodeficiency and therefore were not indicators of HIV infection. However, research has shown that some cancers that were originally considered non-AIDS-defining, such as Hodgkin’s disease and lip cancer, are in fact associated with immunosuppression and thus could be moved from the non-AIDS-defining to the AIDS-defining cancer group. This association with decreased immune function may suggest either that these cancers are also associated with viruses or that an underperforming immune system makes a person susceptible to more types of cancer than just those caused by infectious particles.
Another study from 2005 looked at how the survival of people with AIDS from cancer has changed since the first cases of AIDS compared to the general population. While this only looked at survival for 24 months after cancer diagnosis, significant improvements were seen since the 1980s in the survival of AIDS patients with certain cancers. In particular, the time period since 1996 and the introduction of HAART (or highly active antiretroviral therapies) has seen marked increases in survival rates, suggesting that if HIV is treated with more effective drugs and the immune system is better protected, then more powerful anti-cancer drugs can be used, which translates to better survival.
A recent article from the Washington Post by Mark Wainberg does a good job of looking at some of the most recent and pressing issues surrounding cancer in people with AIDS. First of all there is the troubling fact that there have been increased cases of severe and untreatable cancers in AIDS patients above the levels in the general population. He attributes this trend to the fact that while antiretroviral drugs can help fight HIV, they cannot repair the immune system to pre-infection levels, and thus may leave a person with a decreased defense against cancer.
This fact and others are cause for concern in the AIDS community. For one, there is always the issue of treating two diseases at once – doctors have to be very careful about the side-effects of mixing powerful drugs in patients while weighing them against the effect of not giving the patient that drug at all. In addition, there is cause for concern about the rising number of cancer cases in people with HIV who have been infected for 5-15 years. Researchers are unsure about what this means for other groups, such as those infected for a longer time. There is always the worry that more and more different types of cancers will start to affect AIDS patients, which makes it harder to treat cancer since almost all types require different treatment regimens and finding drug combinations for AIDS and many different cancers could be a daunting task. These are just some of the many possible challenges that physicians and researchers face in fighting both AIDS and cancer in the coming years.
Wainberg’s article ends by emphasizing the importance of finding drugs that not only help fight HIV replication and spread, but also help repair damage already done to the immune system by the virus. In addition, there is a lot more research that needs to be done in this area to determine whether all the cancers that are occurring in higher numbers in AIDS patients are related to infectious particles or if there is some other way that HIV is causing an increased occurrence of cancer in its hosts. And physicians who deal with AIDS patients need to cooperate with those who treat cancer patients to find effective and safe drug therapies that can treat both diseases at the same time.
With a large portion of the HIV-positive population reaching the age of increased cancer susceptibility, this issue will become more significant in the AIDS community in the coming years. The sooner doctors and researchers start to take on this coming problem, the better the chances that we can find ways to prevent cancer from becoming a huge obstacle in AIDS treatment. While advances in antiretroviral therapy are great steps forward for the fight against AIDS, we need to keep making strides in treatment beyond just controlling the virus and look to anticipate and deal with issues in the treatment of HIV-positive people before they become critical.
That ends this installment of The AIDS Pandemic. I’m Mike Neri, and thanks for listening.