[1st Stage I melanoma of the limbs. Prognosis on the basis of the depth of invasion and maximum thickness]

Abstract

The prognostic significance of 2 histological parameters, the level of invasion and maximum thickness is evaluated in 248 cases of malignant melanoma of the limbs staged T 1-3 N0M0 which were collected for Trial No. 1 of the W.H.O. Collaborating Centres for the Evaluation of Methods of Diagnosis and Treatment of Melanoma between September 1967 and December 1974. There is a linear relation of tumor thickness to mortality with a high statistical significance (P = 0.0002). Mortality also increases with progression of the level of invasion. The incidence of occult metastases to the regional lymph nodes increases with increasing thickness or level of invasion. Moreover, the age and sex adjusted survival curves are also dependent on both parameters. The comparison of the two methods revealed that the maximal tumor thickness is a more reliable prognostic factor than is the determination of the level of invasion.