Malignant melanoma: significance of disease-free interval.

One hundred and six patients dying of malignant melanoma have been studied to test alternative explanations of long disease-free intervals following primary excision. The time intervals from excision to relapse with local, lymphatic-borne or blood-borne recurrences do not correlate with the subsequent survival of the patient. If the experimental technique is valid, it supports the hypothesis that a long latent interval following primary excision represents a variable period of growth restraint followed by reactivation of disease rather than a period of continuous tumour growth throughout the disease-free interval.