A large cohort study of non-AIDS-defining cancers in people with HIV has found that while lung cancer was responsible for 16% of cases of these cancers it was responsible for 37% of non-AIDS-defining cancer deaths. Anal, liver, prostate and head and neck cancers and Hodgkin's lymphoma were also common but without lung cancer's high mortality rate.
The D:A:D study is a major cohort study of 35,000 patients in Europe, the US and Australia and has previously been responsible for a wealth of data on drug side-effects and conditions like diabetes and cardiovascular disease.
This study collected cases of, and deaths from, non-AIDS-defining malignancies (NADMs - cancers) from eight out of eleven national cohorts in D:A:D between the start of 2004 and the end of January 2010. NADMs include all cancers except the AIDS-defining ones which are the most strongly related to low CD4 counts: Kaposi's sarcoma, cervical cancer and non-Hodgkin's lymphoma.
The study found 880 NADMs altogether, representing an incidence of one NADM diagnosed per 200 patients a year. Eighty per cent of cases were men partly because there are more men than women in the D:A:D cohort but also because men were 52% more likely to develop NADMs. The average latest CD4 count of cases was 327 CD4 cells/mm3 and the median lowest-ever count 127 CD4 cells/mm3: the vast majority were on antiretrovirals and the median viral load was 50 copies/ml, though 25% had viral loads over 250 copies/ml. One-third of the cohort were smokers.
The most common cancer was lung cancer with an incidence of one case per 1000 patients a year; anal cancer, the third most common, was roughly half as common as this. Annual incidence did not change over the six years of the study, except for a suggestion that the second most common cancer, Hodgkin's lymphoma, may have become slightly less so, with incidence changing from roughly one case per 1500 patients a year to one per 2000 in the last two years of the study.
Lung cancer was by some way the most lethal malignancy, with 80% of diagnosed patients dead within 2.5 years: the death rate for lung cancer was 2.3 times the rate for all NADMs. In contrast Hodgkin's lymphoma and anal cancer had half the average death rate of all NADMs, and in the case of Hodgkin's, 25% of patients died not necessarily of the cancer) within the next two years but there were few deaths thereafter.
In multivariate analysis, being an ex-smoker raised the risk of death due to NADMs by 66%. Being a current smoker was associated with a 28% raised risk of NADM-related death, and this was not statistically significant, but this is likely due to current smokers having a raised death rate for other reasons, such as cardiovascular disease, as well as lung cancer.
Being male raised the NADM mortality risk by 52% and having been an injecting drug user by 59%. For each year longer patients had been diagnosed with HIV, their NADM-related death rate increased by 9% and by 5% for every 50 fewer CD4 cells/mm3. Age (an 11% raised risk per five years older) and hepatitis C infection (a 28% increased risk) were of borderline significance in relation to ADM mortality.
Reference
Worm SW et al. Non-AIDS defining malignancies (NADM) in the D:A:D study: time trends and predictors of survival. Thirteenth European AIDS Conference, Belgrade, abstract PS2/1, 2011.