It is well known that smoking raises the risk of lung cancer. There have also been studies to show that the risk of lung cancer is greater for people living with HIV (PLWH). A new study has shown that the risk is especially high for people who at some time in the past had a severely weakened immune system. This is often the case for people who were diagnosed with HIV very late, with a low CD4 count (below 200 is considered low; below 50 very low).

When the immune system is damaged, opportunistic infections and AIDS-defining illnesses such as pneumonia can occur. Pneumonia is an infection of the lungs that causes inflammation. People diagnosed late with HIV often suffer from PCP (Pneumocystis pneumonia, also now referred to as Pneumocystis jirovecii).  This new study suggests that the damage to the lungs may be long-lasting enough to further raise the risk of lung cancer years later.

The study comes from the United States, looking at lung cancer rates in PLWH and a comparison group of people without HIV. Around 6800 people stayed in the study for around ten years each. Within this group, 60 people had lung cancer. All of them were smokers and those who smoked the most were the most likely to have lung cancer. But the researchers also found that people who’d previously had pneumonia due to HIV or AIDS were more likely to have lung cancer. Among those with HIV who had lung cancer, over half had previously had an AIDS-defining illness and in most cases this was pneumonia.

Lung cancer is very difficult to treat. Not smoking and stopping smoking are the best ways to avoid it.

The full article can be read here.