0726 Cancer risks in HIV-positive children and adolescents

HIV infection is said to increase the risk of cancer in children by a factor of 5. Obvious questions would be whether the virus itself is oncogenic, whether treatments are oncogenic or whether it is the immune suppression that predisposes patients to malignancy. In a meta-analysis comparing cancer rates in adults post-transplant vs adults with HIV, for the most part (20 of 28 cancer types studied) there was a significant increase in both situations, with most of the cancers having a known infectious cause. These included EBV-related cancers such as Hodgkins and non-Hodgkin lymphomas, HHV-8-related Kaposi sarcoma, HBV and HBC-related liver cancers, Helicobacter-related stomach cancer, and HPV-related cancers involving the cervix, vulva, vagina, anus, and oral cavity/pharynx. The conclusion drawn is that the susceptibility to cancer is largely the consequence of the immune disorder. Studies in children have shown higher than expected rates of non-Hodgkin and Hodgkin’s lymphoma, Kaposi sarcoma and leiomyosarcoma. For the most part the relationship to infection is again apparent. The good news is that HAART has been shown to substantially reduce the cancer risk, and in an observational study of 1190 perinatally-infected children in Italy, pre- and early-HAART cancer rates of around 4.0-4.5 per 1000 children per year dropped to 0.76 in the late-HAART period (overall period covered from 1996-2004). Not so reassuring is a study from Harvard, USA that followed perinatally-infected girls through to early adolescence: 48 of 101 girls had abnormal Pap smears (18 with atypical cells, 27 with low-grade squamous intraepithelial lesions (SIL); and 3 with high-grade SIL).

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