NONMELANOMA SKIN-CANCER IN JAPANESE ETHNIC HAWAIIANS IN KAUAI, HAWAII - AN INCIDENCE REPORT

Background: Incidence reports of nonmelanoma skin cancer (NMSC) in Japanese persons are limited. Most studies have relied primarily on hospital records or voluntary reporting systems. Objective: Our purpose was to determine the incidence of basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and Bowen's disease (BD) in a defined Japanese population. Methods: A prospective 5-year population-based incidence study was conducted on the island of Kauai, Hawaii from 1983 through 1987. Results: Thirty Japanese Kauai residents, 12 men and 18 women, developed BCC during the 5-year study period. At the same time, 24 Japanese, 6 men and 18 women, were identified with SCC, and 11 had BD, three men and eight women. When standardized to the Japanese population in Japan, the annual BCC incidence rate was 30 per 100,000 Japanese Kauai residents with an average patient age of 75 years. More than 80% of these BCCs were localized to the head and neck. New BCCs developed in four patients with BCC, but none was a recurrence of a previously treated lesion. Five patients with BCC had SCC or BD concurrently or at other times. The SCC incidence was 23 per 100,000 Japanese Kauai residents with an average patient age of 80 years. The head and neck were again the most common anatomic sites. New SCCs subsequently occurred in two patients, in one of whom a localized recurrence also developed. Five patients with SCC had BCC simultaneously or at other times. The incidence of BD was 13 per 100,000 Japanese Kauai residents with an average patient age of 74 years. The extremities were the most common anatomic sites. One patient later had a new BD lesion and a recurrent BD lesion. Two patients had BCC or SCC at other times. Conclusion: We report incidence rates of BCC, SCC, and BD at least 45 times higher in the Japanese population in Kauai, Hawaii than rates for the Japanese population in Japan. Kauai's intense UV radiation and emphasis on outdoor activities may contribute. More Japanese women had NMSC than men, a sex difference not observed in Japan.