Human Papillomavirus-Related Cancers Among People Living With AIDS in Puerto Rico

The objective of this study was to estimate the incidence of cancer and human papillomavirus (HPV)–related cancers and the risk of death (by cancer status) among people living with AIDS (PLWA) in Puerto Rico. We used data from the Puerto Rico AIDS Surveillance Program and Central Cancer Registry (1985–2005). Cancers with highest incidence were cervix (299.6/100,000) for women and oral cavity/oropharynx for men (150.0/100,000); the greatest excess of cancer incidence for men (standardized incidence ratio, 86.8) and women (standardized incidence ratio, 52.8) was for anal cancer. PLWA who developed a cancer had decreased survival and increased risk of death compared with those who did not have cancer. Cancer control strategies for PLWA will be essential for improving their disease survival.

measured the median survival time of PLWA to describe survival by cancer status and period of AIDS diagnosis. To assess the risk of death we estimated the hazard ratio (HR) of death with 95% confidence intervals (CIs) by using the Cox proportional hazards model, stratified by sex and period of AIDS diagnosis. Cases lost to follow-up and those alive at December 31, 2008, were censored. The proportional hazards assumption of the Cox model was tested and validated and an interaction assessment was performed. We used Stata 12.0 (Stata Corp, College Station, Texas) for the statistical analysis.

Results
The distribution of PLWA varied by sex, age, mode of HIV exposure, and period of AIDS diagnosis ( Table 1). The proportion of women who had an HPV-related cancer was larger than the proportion of women who had a non-HPVrelated cancer or no cancer; we found similar results for PLWA whose HIV was transmitted heterosexually.
The highest incidences were for cervical cancer (299.6/100,000) among women and for oral cavity/oropharyngeal cancers (150.0/100,000) among men; anal cancer was the second leading cancer among both sexes. We found an excess of cancer incidence (overall, HPV-related, and non-HPV-related) among PLWA during both periods of AIDS diagnosis. Among HPV-related cancers, the greatest excess of incidence was for anal cancer among men (SIR = 86.8; 95% CI, 51.5-137.2) and women (SIR = 52.8; 95% CI, 10.9-154.3). We observed similar patterns in both time periods and for certain HPV-related histologies (

Discussion
Our study updates information on the cancer burden among PLWA in Puerto Rico with a focus on HPV-related cancers and presents the first statistics on cancer survival and risk of death for this group. Consistent with studies worldwide and in Puerto Rico (6), the burden of cancer (9) and HPV-related cancers (1,2,10,11) was higher among PLWA than among the general population. Although comparisons should be made cautiously because of the different methods used by these studies, our study suggests higher excess incidence of cancer and HPV-related cancers among PLWA in Puerto Rico than in other populations (2,9,11).
In both periods of diagnosis, the highest excess incidence for cancer was for anal cancer. This result highlights the need for anal cancer screening among PLWA, although further research on this area is warranted (12,13). Given the lack of guidelines on anal cancer screening, clinical trials that determine the effectiveness of the Papanicolaou test for anal cancer prevention are needed (11). HPV vaccination (4) should be promoted in Puerto Rico, where vaccine uptake is low (14). Young PLWA should be targeted in vaccination efforts, although additional studies of vaccine efficacy among PLWA are needed (15).
We also documented decreased survival and increased risk of death (significant only for non-HPV-related cancers) among PLWA who developed a cancer compared with those who did not. Our study supports the importance of strengthening cancer screening and providing access to care among PLWA to decrease the incidence of cancer and improve survival and quality of life. Although the small number of HPV-related cancers among PLWA reduces the precision of our estimations, we conclude that PLWA in Puerto Rico have a greater burden of cancer than the general population, and this burden has a negative impact on survival. Further research and cancer prevention and control strategies are needed to reduce health disparities among PLWA in Puerto Rico. The cancer and HIV/AIDS surveillance systems should collaborate in cancer surveillance among PLWA for disease monitoring and intervention assessment.