Changes in survival with clinical stage I malignant melanoma

Inclusion of patients referred to our cancer center following recurrence, by retracing the history and characteristics of these patients back to when they were in stage I, produced a bias that lowered the estimated disease-free survival rates. However, taking into consideration only patients referred and managed in our center when they had clinical stage I melanoma, significant differences in disease-free survival over time were revealed (P = 0.03). Thus, the estimated five-year disease-free survival rate for 86 patients treated in the period 1971-75 was 65%, whereas that from 115 patients treated in the period 1976-80 was 81%. There was no significant increase in disease-free survival for patients who had an elective node dissection in addition to wide excision.