Trends of skin cancer in the Canton of Vaud, 1976-92.

Trends in incidence and mortality for basal cell carcinomas (BCC), squamous cell carcinomas (SCC) and cutaneous malignant melanoma (CMM) for the period 1976-92 were analysed using data from the Cancer Registry of the Swiss Canton of Vaud. Among the 12,473 cases registered, 63% were basal cell carcinomas, 25% squamous cell cancers, 9% cutaneous malignant melanomas and 3% other miscellaneous histological types. Age-standardised incidence rates increased substantially for all histological types considered, from 44% increase for BCC in males to a more than 3-fold increase for SCC in females, with only signs of a levelling off in 1991-92, following a peak of incidence rates in 1986-90. From 1976-80 to 1991-92 CMM incidence increased by approximately 80% in both sexes. In 1991-92, age-standardised (world) incidence rates per 100,000 were 69.3 for basal cell, 29.1 for squamous cell cancers and 11.5 for melanomas in males, and, respectively, 62.2, 18.0 and 12.3 in females. With respect to mortality, in males rates increased for both non-melanocytic cancer (> 40%) and CMM (> 53%) whereas in females CMM, BCC and SCC rates remained approximately stable over the calendar periods examined. In 1991-92, age-standardised mortality rates per 100,000 were 2.6 for melanoma and 0.7 for other skin cancers in males, and, respectively, 1.6 and 0.2 in females. Upward trends in incidence were also present, and relatively homogeneous across, various age groups examined. However, SCC and CMM levelled off over the last period, and some decline was apparent in males below age 45. Separate analysis by anatomical site showed substantial increases in the head and neck for SCC and BCC, and in the trunk for CMM. In 1991-92, middle-aged women had almost equalled male incidence rates of BCC and SCC. A female excess of CMM incidence seemed to have disappeared since 1981-86. The increase in skin cancer incidence thus continued in this population up to the late 1980s, with a plateau only after 1990.