Kaposi's sarcoma reporting in San Francisco: a comparison of AIDS and cancer surveillance systems

A preliminary comparison of the reported incidence of Kaposi's sarcoma among males under 60 years of age residing in San Francisco was conducted using merged San Francisco AIDS Registry and California Tumor Registry (CTR) data. For the years 1980-1986, the number of cases reported by both registries was similar. However, only 961 (72.3%) of the 1,330 cases appearing in either registry appeared in both. Of the 160 Kaposi's sarcoma cases in the AIDS registry only, 11 (6.9%) were included in the CTR with another cancer diagnosis. Of the 209 Kaposi's sarcoma cases occurring only in the CTR, 109 (52.2%) were included in the AIDS registry with another diagnosis. The number of cases included in either or both registries was about 20% more than in either alone. Data sharing between the staff of these registries is precluded by confidentiality constraints.