Antiretroviral therapy (ART) has improved the life expectancy of people living with HIV (PLWH) dramatically. However, there has been a parallel shift in causes of death from AIDS to non-AIDS-related diseases. Given that 40% of PLWH smoke cigarettes — more than double the smoking prevalence of the general population — it is not surprising that tobacco-related disease ranks high among these causes. Furthermore, smoking and HIV appear to work synergistically to increase the risk for lung cancer development.
To estimate the projected lung cancer burden caused by smoking among PLWH, a microsimulation model-based analysis was conducted. The analysis used standard demographic data and recent HIV/AIDS epidemiology statistics along with specific details on smoking exposure, smoking status, and smoking intensity to determine the cumulative lung cancer mortality by aged 80 years for patients who entered HIV care in the United States at aged 40 years.
Men and women with HIV who were moderate smokers and continued to smoke had a risk of dying from lung cancer of 23.0% and 20.9%, respectively, vs 6.1% and 5.2% for those who quit smoking at aged 40 years, and 1.6% and 1.2% for never smokers. Higher risk was associated with heavier smoking and decreased risk with lighter smoking. Compared with never smokers, lung cancer risk ratios for male and female current moderate smokers were 23.6 and 24.2, respectively, and those who quit smoking at aged 40 years had risk ratios of 4.3 and 4.5, respectively.
With the success of ART, PLWH now have a life expectancy that approaches that of the general population. However, HIV confers an added risk for lung cancer. As a result, ART-adherent smokers are 6 to 13 times more likely to die from lung cancer than from traditional AIDS-related causes. Ultimately, 9.3% of PLWH are expected to die from lung cancer unless smoking in this population decreases substantially.
Reddy KP, Kong CY, Hyle EP, et al. Lung cancer mortality associated with smoking and smoking cessation among people living with HIV in the United States [published online September 18, 2017]. JAMA Intern Med. doi:10.1001/jamaintermed.2017.4349