Compliance with follow-up and prognosis among patients with thin melanomas.

The aim of this study was to report on the compliance with follow-up among patients with thin melanomas. We also examined the prognosis of patients with recurrent disease and whether there were any differences in prognosis associated with the time between the last follow-up examination and the onset of recurrence. A retrospective analysis of the records of 513 consecutive patients (50.3% males, mean age: 52.8+/-16.9 years) with thin melanomas (<1.5 mm Breslow thickness) was carried out. The estimated cumulative proportion of patients who still continued their follow-up examinations 5 years after diagnosis of the primary tumour was 55.3% (95% Confidence Interval (CI): 50.4--60.2%). The mean annual drop-out rate was 11.2%. The drop-out rate was similar for males and females and was not influenced by the patients' age or the tumour thickness. Among 263 patients who continued follow-up, 50.2% (n=132) were not compliant with the time schedule. 20 patients presented with recurrent disease after a median of 35.9 months (25--75% percentiles: 16.7--46.5 months). Six patients who did not have a follow-up examination within 1 year before the onset of recurrence presented with more advanced disease and had a worse prognosis (median survival: 12.5 months, hazard ratio: 3.5, 95% CI: 1.1--17.1, P=0.04), than those patients, who had a recent follow-up examination before the onset of recurrence (n=14, median survival: 22.3+ months). In the majority of recurrent cases with good prognosis, metastatic disease was confined to the regional lymph nodes and the presumptive diagnosis of metastatic disease was either made by palpation or by sonography of the regional lymph nodes. The observed drop-out rate of patients during the first 5 years of follow-up is substantial and does not depend on the patients' age, sex or on the tumour thickness. Although the frequency of recurrences among patients with thin melanomas is low, regular follow-up examinations including physical examination, as well as palpation and sonography of the regional lymph nodes, are essential.