This is a proposal to continue a case-control study to test the hypothesis that infection with human papilloma virus (HPV) is related to an increased risk of vulvar cancer. The study will be conducted in three of the counties of Western Washington that are covered by the population-based Cancer Surveillance System (CSS), a tumor registry that participates in the Surveillance Epidemiology and End Results Program (SEER) of the National Cancer Institute. Female residents who are diagnosed with invasive or in-situ vulvar cancer during January 1986 - June 1990 (approximately 200 cases) will be identified and invited to participate. Cases and two control groups will be interviewed regarding a history of sexually-transmitted diseases, as well as other known risk factors for vulvar cancer. Tissue specimens will be collected from each case and from a control group of women who were surgically treated for certain benign vulvar conditions. These samples will be examined using molecular hybridization techniques for specific types of HPV. A second population-based random digit dialed control group will be included, but tissue specimens will not be collected from this group. Blood samples will be collected for all cases and controls and analyzed for evidence of prior exposure to sexually transmitted viral infections (a sample of blood will be stored for analysis when a test for HPV becomes available). The information from these cases and controls will be added to that of the approximately 210 cases and 300 controls interviewed under the current grant to facilitate independent analyses of in-situ and invasive vulvar cancer assessing the relative risks associated with specific HPV type, allowing for confounding and interactions with other exposures these women may have had.