Survival analysis in patients with cutaneous malignant melanoma

INTRODUCTION: Cutaneous malignant melanoma (MM) takes only 3% of all malignant tumours of the skin, but for reason of its increased frequency and pronounced tendency to rapid growth and metastases, it causes 60% of total lethal outcomes due to malignant tumours of the skin 1]. Primary MM is a diagnostic problem because of the great variety of its clinical features. Asymmetric configuration, irregular border, speckled color(r)diameter of more than 6 mm, and elevation of the surface, suggest suspicion of malignant alteration, but even then misdiagnosis is possible. For the final diagnosis of MM histopathological confirmation is necessary. The method to use is the extensive excisional biopsy of the lesion and its borders 2]. Histopathological diagnosis is based on microscopic findings which include: histogenetic type of MM, tumour thickness according to Breslow, level of invasion according to Clark, presence of ulceration, grade of lymphocyte infiltration, mitote rate, type of cells, presence of melanin in cells 2, 3]. PATIENTS AND METHODS: A five-year survival of patients with cutaneous malignant melanoma (MM) was studied according to sex, age and distinct features of the tumour: site, type of initial therapy, stage of the disease, time from the first signs of the disease to diagnosis of MM, histological findings (histogenetic type, Breslow's tumour thickness, Clark's level of invasion, presence of ulceration, degree of lymphocyte infiltration, number of mitoses, type of cells, intensity of pigmentation) and presence of metastases. The retrospective study included 336 patients with cutaneous MM. There were 185 female (55.1%) and 151 male patients (44.9%), aged 14-83 years, mean age 48.8 years, who were treated at the institute of Oncology and Radiology in Belgrade from 1978 to 1990. The mean follow-up was 60 months (1-144 months). Melanoma in situ had 16 (4.1%) patients. Stage I had 45 patients (14.1%), stage II 163 (48.5%), stage III 83 (24.7%) and stage IV 29 (8.6%) patients. Acral location on hands and feet had 40 (11.9%) patients, on head and neck 36 (10.7%), on the trunk 146 (43.5%) and on the extremities (except hands and feet) 114 (33.9%) patients. Nodular melanoma (NM) was the most frequent histogenetic type revealed in 150 (44.6%) patients, superficial spreading melanoma (SSM) in 105 (31.1%) patients, acral melanoma (AM) in 39 (11.5%) and lentigo malignant melanoma (LMM) in 32 (9.4%) patients (Table 1). Five-year survival rate was calculated according to Kaplan-Meier's method and significance of the difference between some categories was tested by Long-Rank's test; the significance less than 0.05 was accepted. RESULTS: Statistically highly significant differences in a five-year survival (p < 0.01) were related to sex p = 0.0005, age p = 0.0017, tumour site p = 0.0025, initial therapy p = 0.0036, stage of MM p = 0.0000, histological features of the tumour p = 0.0000 and presence of metastases p = 0.0000. A better five-year survival prognosis was found in female patients (64.5%) compared to male patients 44.5%, aged 27-46 years (87.3%) compared to patients younger than 26 years (43.5%); patients with melanoma on the extremities (except hands and feet) had a better five-year survival (66.7%) compared to patients younger than 26 years (43.5%); patients with melanoma on the extremities (except hands and feet) had a better five-year survival (65.7%) compared to patients with melanoma on the trunk or acral melanoma (47.3%). Higher survival was recorded in the group of patients with the tumour 1.5-3 mm thick, in whom the tumours was excised and regional nodes dissected as the primary therapy (66.9%) compared to those who underwent excision of the tumor only (48.8%). A five-year survival of patients with MM in situ was 100% for those in stage I; 85% in stage II; 42% in stage III, 16% and 0% in stage IV. The patients in whom the diagnosis of MM was established within 10 months after the first signs of the disease had significa