Changes in nonmelanoma skin cancer incidence between 1977-1978 and 1998-1999 in Northcentral New Mexico.

Nonmelanoma skin cancer (NMSC) is a highly common form of malignant disease in light-skinned populations. In 1977-1978, the National Cancer Institute sponsored a population-based skin cancer survey that found marked geographic variability in the incidence of NMSC within the United States. Some of the highest rates were observed in the southwestern state of New Mexico within its non-Hispanic white population. We recently undertook a follow-up survey of NMSC in New Mexico and report here incidence rate data for non-Hispanic white residents of a three-county area in northcentral New Mexico for two 12-month time periods: June 1, 1977 to May 31, 1978 and July 1, 1998 to June 31, 1999. Our results show that incidence rates of basal cell carcinoma increased by 50% in males and 20% in females, whereas rates of squamous cell carcinoma roughly doubled in both males and females. Temporal analysis of rates according to major anatomical site showed the head and neck was consistently the most frequent site of occurrence, however, the greatest percentage increase in rates over time occurred at the upper and lower limbs. These findings are consistent with those reported for various other populations showing the incidence of NMSC has measurably increased since the 1970s.