HIV patients who take their medication but also smoke are about 10 times more likely to die from lung cancer than from AIDS-related causes, a new study estimates.
Lifesaving antiretroviral drugs have improved life expectancy to the point that patients now have more to fear from tobacco than HIV, said lead researcher Dr. Krishna Reddy.
“Thanks to antiretroviral medicines, people with HIV are living longer,” said Reddy, a pulmonologist and critical care doctor with Massachusetts General Hospital in Boston. “The bad news is that they’re living long enough to get cancer.”
Based on the new findings, smoking cessation should be a focus of treatment, he and his colleagues said.
More than 40 percent of people with HIV are smokers, a rate more than double that of the general population, Reddy said.
Fatalism and depression among HIV patients often lead them to take up the habit, even though the threat of HIV has decreased significantly for those who take their medication as prescribed, Reddy said.
An evidence review published in The Lancet in May found that HIV patients on antiretroviral therapy stand an excellent chance of reaching old age. For example, average 20-year-olds starting treatment today will live into their mid-60s, the review found.
“In the past, most people didn’t live long enough to face the consequences of smoking. Smoking wasn’t commonly thought of as a threat to their health,” Reddy said. “Unfortunately, there is still a feeling among people with HIV that, ‘well, I have HIV, that’s what is going to kill me, it doesn’t matter if I smoke.'”
Reddy and his colleagues created a computer model to project the risk of lung cancer among people with HIV, taking into account whether they are current or former smokers and how many cigarettes a day they smoke.
Prior studies have shown that HIV infection increases the risk of lung cancer separate from smoking, Reddy said.
Tobacco smoke and HIV both promote inflammation and infections in the lungs, which increase cancer risk. “You put those two together and the risk becomes very high,” Reddy said.