If people living with HIV who smoke quit their cigarette habit, they soon cut their risk of numerous cancers, aidsmap reports. However, unlike HIV-negative people who quit smoking, HIV-positive ex-smokers maintain a much higher, non-declining risk of lung disease for at least five years to follow.

Researchers from the D:A:D cohort analyzed data on all the HIV-positive participants’ cancer incidence between 2004 and 2015. They compared the cancer rates between those who currently smoked, never smoked, who had quit cigarettes before entering the study and who quit during the study.

Findings were presented at the 2017 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.

A total of 35,424 participants, 46 percent of whom were smokers and 20 percent of whom were ex-smokers, were diagnosed with 1,980 cancers between them, including 242 lung cancers, 487 other cancers considered related to smoking and 1,251 other cancers not considered related to smoking.

The notable proportions of cancers occurring in each of the four groups of participants were as follows: lung cancer, 70 percent among current smokers and 21 percent among ex-smokers; other smoking-related cancers, including head and neck, esophageal, stomach, pancreatic, kidney and urinary, ovarian and liver cancer, 52 percent among smokers and 21 percent among ex-smokers; cancers not related to smoking, 47 percent among smokers and 20 percent among ex-smokers.

The researchers found that for about the first year or so after quitting cigarettes, the participants’ risk of smoking-related cancers, save for lung cancer, fell dramatically and after that hit a level comparable to that of nonsmoking people with HIV. This drop in risk was unaffected by participants’ age, CD4 count or sex.

With regard to lung cancer, after the researchers adjusted the data for various factors, they found that the risk remained 8.26-fold higher for ex-smokers for as long as five years after they quit cigarettes compared with HIV-positive never smokers. HIV-negative smokers, on the other hand, start to realize a decline in risk of lung cancer within five years of quitting.

To read the aidsmap article, click here.

To read the conference abstract, click here.