Primary cutaneous malignant melanoma: experience of the British Columbia Cancer Agency from 1972 to 1981.

A retrospective review of 891 patients with newly diagnosed primary cutaneous malignant melanoma (CMM) registered at the British Columbia Cancer Agency from 1972 to 1981 is presented. Age-standardized incidence rates in British Columbia have increased markedly over that time. The female-to-male ratio was 1.13:1 and the median age overall was 47 years. A change in the size of a mole was the most common presenting sign (in 43% of patients) and the median duration of signs was 5.9 months. Predominant tumour sites were the trunk for males and the lower limbs for females. Dominant growth patterns were superficial spreading melanoma (65%), nodular melanoma (25%), lentigo maligna melanoma (5%) and acral lentiginous melanoma (2%). On staging of the primary tumour, 90% of patients had local disease, 9% of patients had regional disease and 1% of patients had distant disease at presentation. Median depths of tumours were 1.45 mm for males and 1.10 mm for females; no T1 tumours (tumours 0.75 mm or less in depth [TNM classification]) were staged beyond the local area. Disease recurred in 44% of males and 32% of females. The 15-year survival rate was 55.5% for males and 70.3% for females. These findings are compared with those of recent international series. It is apparent that earlier diagnosis improves survival and that more education is needed in view of the increasing incidence and death from CMM.