Squamous cell carcinoma in Kauai, Hawaii.

BACKGROUND: It is estimated that over 100,000 new cases of squamous cell carcinoma are diagnosed in the United States annually. This number is compounded by an increasing concern over the ozone layer depletion and the continued sunbathing behavior of many individuals. This could be particularly acute in Hawaii, which may have the highest rates of skin cancer in the country. We believe the updated information on skin cancer is essential to address the magnitude of the problem.

METHODS: A prospective 5-year population-based incidence study was conducted on Kauai, Hawaii, between 1983 and 1987 to investigate the frequency of squamous cell carcinomas in resident Caucasians.

RESULTS: A total of 58 residents, 37 men and 21 women, were identified with an initial episode of squamous cell carcinoma during the 5-year period. The average annual incidence rate per 100,000 Kauai Caucasian residents, standardized to the 1980 U.S. white population, was 153 for men and 92 for women with a combined rate of 118. The average patient age was 66.4 years. The head and neck was the most common anatomic site, with the extremities second. Subsequent new squamous cell carcinoma occurred in 13.8% of patients. Only one patient (2%) developed a recurrence after treatment. Twenty-five patients (43%) had basal cell carcinoma simultaneously or at other earlier times.

CONCLUSIONS: In Kauai the incidence rate of squamous cell carcinoma is the highest yet documented in the United States. No consistent trend in incidence rates was appreciated during this 5-year period.