Revisiting the gender-linked melanoma burden.

BACKGROUND: Much is known about the worldwide rising incidence of skin cancers in the white populations. However, contradictory reports have been presented about a gender-linked risk for malignant melanoma (MM). OBJECTIVE: To review the recent epidemiological information about primary and metastatic MM in south-east Belgium. METHODS: Laboratory records of primary MM according to age and gender were compared per 3-year periods from 1988 to 2002. The numbers of MM per decade of patient age were corrected with regard to the number of citizens in the defined periods of age. This led to the calculation of the rate of estimated prevalence (REP). The same assessments were performed on 187 sentinel lymph node biopsies collected during the last 3-year period. RESULTS: A total of 1,051 primary MM in women and 594 primary MM in men were diagnosed over the 15-year period. The female-to-male ratio rose by 24% over time, with a mean value of 1.77. The most recent years showed a marked increase both in the numbers and REP of primary MM. This situation was present in both genders, although it was most prominent in women of the reproductive age. MM metastases were found in 38/187 sentinel lymph nodes with a female-to-male ratio of 2.17. The age distribution for all sentinel lymph node biopsies copied that of primary MM, but the vast majority of the nodal metastatic MM was found in patients older than 50 years. The ratio between MM metastases and primary MM reached 6.1% (12/198) in men and 6.9% (26/378) in women. CONCLUSION: A recent increase in primary MM incidence was observed in our laboratory. The most likely cause is ascribed to more sensitive MM detection using the combination of clinical dermoscopy and laboratory immunohistochemistry. During the past 15 years, women were more affected than men by both primary and metastatic MM. The gender difference in incidence of primary MM has progressively widened due to an increased incidence in young and middle-aged women. By contrast, nodal metastatic MM mostly affected postmenopausal women.