Malignant Melanoma in southern Sweden; Histopathology, Prognosis and Aetiology

Sammanfattning: The purpose was to study the prognostic and aetiologic risk factors for melanoma in correlation to histopathology. Paper 1-3: Thin tumours (<0.8 mm), tumours with inflammation and median age at diagnosis were signifcantly increasing in 711 CMM patients during the period 1965-89. No difference was found in median thickness. Factors that significantly improved prognosis were; thin tumour thickness, absence of ulceration, female gender, tumour location on extremities, young age and moderate/much tumour inflammation. Correlations between different factors were found, e.g. tumour localisation predominating on the back in males and on the legs in females. LMM (Lentiginous Malignant Melanoma) was seen in combination of old age and facial tumour site. Further there was a relation between thicker tumours and deeper invasion, nodular type (NM), ulceration and older age. Tumours with inflammation were related to thinner tumours, younger age, male sex, location on non-extremities and absence of naevus cells. Paper 4: In a case-control study including 366 CMM patients, a history of melanoma in the family was significantly related to thin tumours (<0.8 mm), tumour site on the trunk and non-significantly associated to younger age at diagnosis. Further the risk for developing SSM-type was significantly increased with the tendency to freckle, raised naevi, propensity to sunburn and decreased with out-door occupation. The NM-type was associated with the presence of raised naevi on the forearm and to sunburn. Absence of naevus cells in the tumour had a significant correlation to sunburn and the presence of raised naevi. Paper 5: From families with CDKN2A-mutation 26 CMM patients were identified and matched with each 3 controls. The invasive level according to Clark was significantly lower among cases compared to controls. No significant differences were seen for tumour thickness. Compared to a population-based material (n=667), cases were significantly younger at diagnosis (median age 42 vs. 61 years) and had less regressive reaction in their tumours.