Effects of tobacco smoking on cancer and cardiovascular disease in urban black South Africans
Aside from the neoplasms that are clearly related to immunodeficiency, such as non-Hodgkin's lymphoma and Kaposi's sarcoma, numerous observations have also shown an association between HIV infection and the incidence of cervical and anal neoplasms. Human papillomavirus (HPV) is the etiologic factor in anogenital neoplasms, although the mechanisms of the association are not clearly understood. It is believed that several HPV genes are critical in the malignant cell transformation process. An etiologic similarity exists between cervical and anal neoplasms, and the risk factors for the former appear to be the same for the latter, such as history of anal or genital warts, history of sexually transmitted diseases (STDs), and certain sexual practices. In addition, a number of studies have shown a relation between HIV-induced immunodeficiency, HPV infection, and the development of anal neoplasms. In a study of 210 men, anal intraepithelial neoplasia was more common in HIV-infected patients than non-HIV-infected patients. Additional risk factors for abnormal cytology included CD4 count under 200, and a history of smoking. Patients who receive surgical treatment for anal carcinoma have been shown to have poor outcome and short survival. Standard treatments, including ablation, surgery plus radiotherapy for small localized lesions, and radiotherapy plus chemotherapy, are preferable for anal neoplasia. Due to the increasing incidence of HPV infection as a manifestation of HIV disease, strategies for screening and treating these patients must be refined.