Relationship between disease-free interval and survival in patients with recurrent melanoma.

A total of 2468 patients with recurrent melanoma were subdivided on the basis of disease-free interval: group 1 had recurrences within 1 year (n = 810), group 2 at years 1 to 3 (n = 1001), group 3 at years 3 to 5 (n = 363), group 4 at years 5 to 10 (n = 329), and group 5 after 10 years (n = 145). Ten-year survivals were 21%, 23%, 25%, 28%, and 35%, respectively. Patients who had recurrences within 1 year had a decreased median survival compared with those who had later recurrences, although the differences were not clinically significant (only 6 to 8 months). Survival was improved for the few patients who had recurrences longer than 10 years from diagnosis. However, for the majority of patients, who had recurrences between 1 and 10 years, the disease-free interval did not predict subsequent survival. The data support the hypothesis that malignant cells can exist in a state of relative quiescence for extended periods. Once disease reactivation occurs, however, the subsequent survival is relatively predictable and is independent of the initial period of tumor dormancy.