Melanoma incidence in central Italy will go on increasing also in the near future: a registry-based, age-period-cohort analysis.

The aim of the study was to evaluate malignant melanoma incident trends in central Italy by means of an age-period-cohort approach. A total of 1977 malignant melanoma (15-84 years) incidents in the area of the Tuscany Cancer Registry between 1987 and 2001 were analysed. Poisson regression has been used to estimate age, cohort and period effect. A nonlinear regression model was used to estimate the expected number of new cases in the period 2002-2006. Incidence rates increased in all age, period and cohort groups. The model that best fitted the data included age and 'drift'. The linear effect ('drift') showed, in each age group, an increase of the risk of malignant melanoma diagnosis of about 36.6% every 5 years of period or cohort. For the period 2002-2006, 1112 new cases were predicted with a standardized rate (age 15-84 years) of 19.2x100.000. In the Tuscany Cancer Registry area, no clues for malignant melanoma incidence rates levelling off were documented. Growing rates and number of malignant melanoma are expected in the near future.