Malignancy burden in aging HIV patients likely to increase

BRUSSELS — Malignancies unrelated to HIV infection are likely to increase as the population ages, according to new data presented here at EACS 2013.

"People who are living with HIV are known to be susceptible to certain types of malignancies, particularly those that are related to chronic immune deficiency," Leah Shepherd, a biostatistician with the University College London, said during her presentation. "So often these malignancies tend to be related to infection. However, infection-unrelated malignancies, which in the general population tend to be associated with aging, are expected to become more prevalent as this population ages."

Leah Shepherd

Shepherd and colleagues assessed the incidence of cancer in 15,648 patients with HIV who were enrolled in the EuroSIDA study. The patients were followed from their first visit or after Jan. 1, 2001, and contributed to 95,033 person-years of follow-up in the study, with a median follow-up of 6 years. Primary diagnoses of infection-related and infection-unrelated malignancies were identified, and the researchers calculated the annual incidence of both cancer types. Regression analyses were used to compare the incidence of malignancies, adjusted for factors such as age, sex, region and ethnicity.

Results indicated that 610 patients developed 643 malignancies, of which 388 (60.3%) were infection-related and 255 (39.7%) were unrelated to infection. The most common types of cancers included non-Hodgkin’s lymphoma (18%), anal (13%), Kaposi’s sarcoma (10%) and lung (9%).

According to Shepherd and colleagues, the crude incidence of infection-related malignancies significantly declined by 4.9% (95% CI, 1.7-7.9) per year, from 6.1 (96% CI, 4.4-8.3)/1,000 person-years of follow-up to 3.6 (95% CI, 2.7-4.9)/1,000 person-years of follow-up. However, the decline in infection-related malignancies was not significant in adjusted analyses (incidence rate ratio [IRR]=1.02; 95% CI, .98-1.06).

The incidence of malignancies unrelated to HIV infection was 2.68 (95% CI, 2.37-3.04)/1,000 person-years of follow-up and remained stable during the study period, both before (IRR=1.03/year; 95% CI, 1-1.07) and after (IRR=1/year; 95% CI, 0.95-1.04) adjusting for confounders.

The researchers said a 10-year increase in age was "marginally" associated with an increased incidence of infection-related malignancies (IRR=1.18; 95% CI, 1.06-1.32) and "strongly" associated with the incidence of malignancies unrelated to infection (IRR=2.11; 95% CI, 1.88-2.36).

Assuming current trends continue, the researchers said the incidence of infection-related malignancies are expected to decline, with 5- and 10-year forecasts of 2.27 (95% CI, 1.13-4.08) and 1.72 (95% CI, 0.86-3.11)/1,000 person-years of follow-up, respectively.

Shepherd and colleagues reported a forecast of a crude incidence of malignancies unrelated to HIV infection of 3.58 (95% CI, 1.38-7.65)/1,000 person-years of follow-up at 5 years and 4.07 (95% CI, 1.56-8.72)/1,000 person-years of follow-up at 10 years.

The researchers said limitations of the study included its observational design, as well as that no cancer-specific analyses were performed.

"Targeted preventive measures and studies evaluating the cost–benefit of screening should possibly be considered," Shepherd said.

For more information:

Shepherd L. Abstract #PS6/5. Presented at: 14th European AIDS Conference; Oct. 16-19, 2013; Brussels.

Disclosure: The researchers report no relevant financial disclosures.