The purpose of this study is to find out why cancers develop in HIV-positive patients.

Cancer is a leading cause of death in AIDS patients. Common cancers in HIV-infected patients include Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL), a cancer of the immune system. Risk factors include certain chemicals, viruses, and perhaps even anti-HIV drugs. Doctors would like to find out which risk factors are most important and how they relate to cancer in AIDS patients.

AIDS-associated malignancy represents a model system for investigations of carcinogenesis. There are few human conditions in which cancer rates are of the magnitude they are in HIV infection. While studies have investigated pre-cancer markers in HIV-infected patients, they have not correlated these markers with tumor samples. This study contributes to understanding oncogenesis of HIV-associated malignancies by establishing a collection of tumors linked with pre-cancer sera and lymphocyte specimens, as well as prospective questionnaire data.

At study entry, patients receive a comprehensive physical exam. Clinic staff interview the patient to collect data regarding medication history (particularly antiretroviral exposure), diet, occupational history, substance abuse, and sexual practices. This information is used to identify behavioral and environmental factors contributing to oncogenesis. In addition, baseline blood samples are analyzed for HHV-8 and EBV levels, anti-EBV and anti-HHV-8 antibodies, CD23, Th2 cytokines, tumor growth factors, chromosomal translocations associated with NHL, and other potential predictors of malignancy. At Month 6 and annually thereafter, patient records are abstracted for data on vital status, AIDS-defining illnesses, medications, and most recent CD4+ T cell and HIV RNA levels. At Years 1, 2, and 3, patients undergo physical exams and blood tests for malignancy surveillance. Any malignancies are biopsied and analyzed for oncogene identification and virology. The medical records of patients who die on study are reviewed to determine the cause of death and to rule out unreported cancer. No treatment is provided by this study.

Inclusion Criteria

You may be eligible for this trial if you:

• Are HIV-positive.
• Have a CD4+ cell count of 200 cells/mm3 or below.
• Are 18 years of age or older.

Exclusion Criteria

You will not be eligible for this trial if you:

• Are not available for follow-up for at least 3 years.