No abstract

Fourteen variables were tested for their ability to predict visceral or bony metastases in 177 patients with clinical Stage I melanoma of intermediate thickness (1.51 - 3.39 mm). A Cox multivariate analysis yielded a combination of four variables that best predicted bony or visceral metastases for these patients: 1) mitoses greater than 6/min 2 (p = 0.0007), 2) location other than the forearm of leg) p = 0.009, 3) ulceration width greater than 3 mm (p = 0.04), 4) microscopic satellites (p = 0.05). The overall prognostic model chi square was 32.40 with 4 degrees of freedom (p less than 10 (-5). Combinations of the above variables were used to separate these patients into at least two risk groups. The high risk patients had at least a 35% or greater chance of developing visceral metastases within five years, while the low risk group had greater than an 85% chance of being disease free at five years. Criteria for the high risk group were as follows: 1) mitoses greater than 6/mm 2 in at least one area of the tumor, irrespective of primary tumor location, or 2) a melanoma located at some site other than the forearm or leg and histologic evidence in the primary tumor of either ulceration greater than 3 mm wide or microscopic satellites. The low risk group was defined as follows: 1) mitoses less than or equal to 6/mm 2 and a location on the leg or forearm, or 2) mitoses less than or equal to 6/mm 2 and the absence in histologic sections of the primary tumor of both microscopic satellites and ulceration greater then 3 mm wide. The number of patients in this series who did not undergo elective regional node dissection (N = 47) was probably too small to detect any benefit from this procedure. Based on survival rates from this and other studies, it is estimated that approximately 1500 patients with clinical Stage I melanoma of intermediate thickness in each arm of a randomized clinical trial would be needed to detect an increase in survival rates from elective regional node dissection.

Fourteen variables were tested for their prognostic usefulness in 203 patients with clinical Stage I melanoma and primary tumor 0.76-169 mm thick. Only two variables, primary tumor location and level of invasion, were useful in predicting death from melanoma for these patients. Of the 12 deaths from melanoma, 11 occurred in patients with primary tumors located on the upper back, posterior arm, posterior neck, and posterior scalp (=BANS). There has been only one death from melanoma in 136 patients with melanoma located at other sites (11/67 vs 1/136, p less than 0.0001 Fisher's Exact Test). Of the 67 BANS patients, 51 had level II or level III lesions and five (10%0 died of melanoma. This compared with six deaths from melanoma in 16 patients (37.5%) with level IV BANS lesions (5/51 vs 6/16, p = 0.01 Fisher's Exact Test). The relatively high incidence of both melanoma deaths and regional node metastases for the BANS group merits consideration for testing the efficacy of elective regional node dissection for these patients.