March 5, 2009
In a poster presentation at CROI 2009 in Montreal, Canada, results from the HIV/AIDS Cancer Match Study show an increase in the risk for mouth (nasopharngeal) cancer and a more modest increase in the risk of certain salivary gland cancers in people with AIDS. Researchers suspect the cause of these cancers is viral, possibly due to Epstein-Barr virus (EBV). The advent of potent HIV therapy did not diminish these increased risks.
In this retrospective study, oral cancer rates were assessed in 503,560 people with AIDS from 1980 to 2004 in the US. Nearly 4 in 5 were men, and the average age at AIDS diagnosis was 38. Information was available for 5 years before an AIDS diagnosis and 5 years following an AIDS diagnosis for each individual.
The results showed that people with HIV had a higher rate of salivary gland cancers compared to rates in the general population. The main types of salivary gland cancers driving this increased rate include lymphoepithelial cell carcinoma (believed to be related to EBV) and squamous cell carcinoma. Overall, a more pronounced increase in the rate of nasopharyngeal cancers was seen, though the EBV-related subtype was not as notable a contributor.
A challenge to this study is that it compared people living with HIV to the general population and did not consider possible increased risks for these cancers among HIV at-risk populations. It also was not able to consider differences in other risks factors, such as cigarette smoking or alcohol consumption and how these may differ among the general population and people with HIV. Regardless, the study does raise awareness about the increased risks for mouth and salivary gland cancers, underscores the importance of oral cancer screening, and is the first study to document an increased rate of these cancers in people with HIV.