Cutaneous malignant melanoma : aspects on recurrence and mortality

Abstract

The purpose of this thesis was to analyse patterns of recurrence and mortality from cutaneous malignant melanoma (CMM) in relation to clinical development and metastatic pathways. The basis of the study consists of patients with CMM, registered and followed within the Stockholm-Gotland regional melanoma care programme, patients included in a national randomized study on the effects of resection margins on outcome, and individuals registered with malignant melanoma as underlying cause of death in the Swedish Cause-of-Death Registry, 1970-1996.

In patients with CMM of >0.8 and <2.0 mm thickness, treated with 2 or 5 cm resection margins, no statistically significant difference in recurrence rate or overall survival was found. Local recurrences (LR) were found to be rare (<1%), as also was the case in the population-based study (1.3%). No major detrimental impact on survival was demonstrated from the LR per se. Survival after first recurrence of CMM was found to depend on type of recurrence. Once the recurrence was manifest, the metastatic pathways were found to be uniform, as well as survival, irrespective of clinical and histopathologic factors associated with the development of recurrent disease. The life table estimate of the cumulative risk of central nervous system metastases was higher when the first event was a regional rather than a local recurrence.

The earlier upward mortality trends seem to have levelled off, with no further increase during the last 10-15 years. A slight decrease was seen for females during the period 1987-1996. This apparent change in trend, which appeared more pronounced in the Stockholm-Gotland region, coincided with intensified preventional activities. Estimates of prognosis for different type of recurrences may be of importance in making clinical decisions. The findings in these studies form the basis for future studies correlating molecular biology of recurrent melanoma and patient outcome.