People living with HIV who adhere to antiretroviral therapy but smoke cigarettes are around 10 times more likely to die of lung cancer than of HIV itself, according to a new study led by Harvard Medical School researchers.
The report, published in JAMA Internal Medicine, suggests that lung cancer prevention through smoking cessation should be a priority in the care of people living with HIV.
“Smoking and HIV are a particularly bad combination when it comes to lung cancer,” said Krishna Reddy, HMS instructor in medicine at Massachusetts General Hospital, who led the study.
“Smoking rates are extraordinarily high among people with HIV, and both smoking and HIV increase the risk of lung cancer,” she added.
People with HIV are now living longer thanks to antiviral medications, but smoking and HIV together put them at higher risk of developing lung cancer than smokers not infected with HIV.
“Lung cancer is now one of the leading killers of people with HIV, but most of these deaths can be prevented,” said Rochelle Walensky, HMS professor of medicine at Mass General and senior author of the study.
Using a computer simulation model of HIV, the researchers estimated the risk of lung cancer among people living with HIV in the U.S. based on whether they are current, former or never smokers, how many cigarettes per day they smoke, or smoked, in the case of former smokers, and whether they consistently take antiviral medications. They also accounted for the risks of other diseases, like heart disease, that are increased by smoking.
The researchers found that nearly 25 percent of these patients who adhere well to anti-HIV medications but continue to smoke will die of lung cancer. Among smokers with HIV who quit at age 40, only about 6 percent will die of lung cancer.
The authors also found that people with HIV who take antiviral medicines but who also smoke are from 6 to 13 times more likely to die of lung cancer than of HIV/AIDS, depending on how much they smoke and and their sex.
Heavy smokers are at even higher risk for lung cancer, with risks of lung cancer death approaching 30 percent. When the researchers focused on people who do not strictly follow recommended HIV treatment, and are thus at greater risk of dying of HIV/AIDS, lung cancer was still estimated to kill more than 15 percent of smokers.
“Quitting smoking is one of the most important things that people with HIV can do to improve their health and live longer. Quitting will not only reduce their risk of lung cancer but also decrease their risk of many other diseases, such as heart attack, stroke and emphysema,” said Travis Baggett, HMS assistant professor of medicine at Mass General and co-author of the study.
More than 40 percent of people living with HIV in the U.S. smoke, compared with 15 percent of the general adult population. Given how common smoking is, the researchers also projected the total number of expected deaths from lung cancer among people currently receiving HIV care in the U.S., taking into account current smoking rates and the imperfect adherence to antiviral therapy that is frequently seen.
They found that nearly 60,000 will die of lung cancer—about 10 percent of all people who are receiving HIV care in the U.S., including both smokers and nonsmokers.
“These data tell us that now is the time for action. Smoking cessation programs should be integrated into HIV care, just like antiviral therapy,” Reddy said.
The study was funded by National Institutes of Health grants K01 DA042687, K23 DA034008, R01 DA015612, T32 HL116275, K01 HL123349, U01 CA199284, R01 MH105203, R01 AI042006 and R37 AI093269, and the Steve and Deborah Gorlin MGH Research Scholars Award.