Trends in the incidence of non-melanoma skin cancer in Slovakia, 1978-1995

Non-melanoma skin cancer (NMSC) incidence in Slovakia in the period 1978-1995 was analyzed. A total of 38 629 microscopically confirmed NMSC cases (19 600 in males and 19 029 in females) were registered by the National Cancer Registry: 31 714 (82.1%) were basal cell carcinomas (BCC), 6396 (16.6%) squamous cell carcinomas (SCC) and only 519 (1.3%) other NMSC. Age-standardized rates of NMSC increased in the given period by 59.1% in males and 58.5% in females. The greatest increase was observed for BCC, 70.4% and 65.0% in males and females respectively, the smaller for SCC, 13.5 and 18.8%. In the period 1993-1995 age-standardized incidence rates per 100 000 were 38.0 for BCC, 6.7 for SCC and 45.5 for all NMSC in males and 29.2, 3.8 and 33.6, respectively in females. The observed marked increase of incidence with age was particularly pronounced for SCC. In both sexes, head and neck was the most common localization of BCC and SCC (84.2 to 74.7%), followed by trunk for BCC (17.0% in males and 10.8% in females) and by upper limbs for SCC (with 11.6% in males and 12.5% in females). Very fast increase of BCC incidence over time, its slower increase with age as compared to SCC incidence and body-site distribution suggest that BCC etiology is much more similar to melanoma etiology than SCC one. Registration of NMSC in relation to changes in possible risk factors (i.e. sun exposure/protection, ozone layer decrease) is important to study the mechanism of disease occurrence and to support public health interventions.