Twenty-five years ago, a diagnosis of AIDS was a nearly immediate death sentence.
But now that patients with the AIDS virus are living longer, doctors are discovering a new set of complications: People with HIV have a much higher risk of developing certain cancers - lung, liver, head and neck, to name a few - and doctors fear that a cancer epidemic among this group could be coming.
Researchers in Maryland, home to one of the nation's largest AIDS populations per capita, are among the leaders in an effort to solve what has become something of a medical mystery.
"We're seeing people we have treated successfully for HIV at much higher risk" for cancer, said Dr. Kevin J. Cullen, director of the University of Maryland's Greenebaum Cancer Center. "The reasons aren't fully understood."
New research presented yesterday by a Johns Hopkins epidemiologist at a national cancer conference shows that patients with HIV are twice as likely as the general population to get any of the cancers not previously linked to the disease. Previous studies have put the risk of developing certain cancers as much as ten times higher for those with HIV.
There are some hypotheses for why this is so: HIV patients are simply living long enough to get cancer diagnoses; their immune systems are weakened by disease or injured by antiretroviral drugs; those with HIV are more likely to engage in high-risk behaviors. One prominent researcher wonders whether HIV drugs themselves could be a carcinogen.
What scientists learn about cancer and the immune system could have ramifications not just for those with HIV but also for everyone else.
"We're really at the first stages of systematically looking at the epidemic and fully looking at cancer," said Dr. William A. Blattner, an associate director of the University of Maryland's Institute of Human Virology. "Before, you died from AIDS, so you didn't have time to develop cancer. ... The unusual observation is the cancers are occurring at a much younger age."
Some of the most common cancers being seen among those with HIV are the ones known to be caused by viruses - such as anal and head and neck cancers, which have been linked to the human papillomavirus, and liver cancer, which has been linked to hepatitis.
One theory is that HIV depresses the immune system, allowing cancer-causing viruses to take hold.
