A profile of invasive cutaneous malignant melanoma in Malta: 1993-2002

Background The incidence of malignant melanoma of the skin has risen in every part of the world where reliable cancer registration data are found. Objective Our study aims to describe the changing incidence of and survival from invasive cutaneous malignant melanoma in Malta, by analysing the data from the 211 cases that were registered at the Malta National Cancer Registry between 1993 and 2002. Results The age standardized incidence rates for invasive cutaneous malignant melanoma rose from 3.7 per 100 000 population per year for males and 5.1 for females in the first 5-year period, to 8.0 per 100 000 population per year for males and 5.9 for females in the second 5-year period. In both sexes, numbers of thin (<= 1.0 mm) invasive melanomas increased significantly between 1993 and 2002; males also registered a significant increase in intermediate-thickness (1.01-4.0 mm) melanomas. The increase in numbers of thin and intermediate-thickness melanomas between the two 5-year periods was greatest in patients aged 60 years and over. The overall absolute 5-year survival rate for the first period was 74% and for the second period 92%. Conclusion Numbers of reported cases of invasive cutaneous malignant melanoma in Malta have more than doubled during the 10-year study period. This is mostly due to a marked rise in the diagnosis of thin melanomas in both sexes, occurring mainly in patients aged 60 years and over. As thin melanomas are of low metastasizing potential, this has resulted in an increase in survival between the two 5-year study periods.