An evidence base for reconsidering current follow-up guidelines for patients with cutaneous melanoma less than 0.5 mm thick at diagnosis.

Background: Despite current guidelines, there is uncertainty about the required duration and frequency of follow-up visits for patients with invasive primary cutaneous melanoma < 0.5 mm thick.

Objectives: To review patients with invasive melanoma thinner than 0.5 mm followed for at least 5 years to provide an evidence base for considering modification of guidelines.

Methods: A retrospective review of 430 patients diagnosed in the west of Scotland during 1992-2001 with melanoma < 0.5 mm was carried out. Recurrence, deaths from melanoma and second primary melanomas were all identified.

Results: From 1992 to 2001, 430 melanomas < 0.5 mm thick at diagnosis were diagnosed out of a total of 3036 primary cutaneous melanomas. To date there have been 593 deaths from melanoma (19%) in the whole group. Five of these deaths were reported in patients with melanomas < 0.5 mm, but on pathological review two were thicker than 0.5 mm at diagnosis (1.5 and > 3 mm), and the remaining three patients all developed thicker second primary melanomas (2.7, 12.0 and 19.0 mm) with a recurrence pattern and timing indicating that these thicker primaries were the cause of death. Fourteen further patients developed a second primary melanoma, and 13 are currently alive and disease free, one dying of other causes.

Conclusions: Our data indicate that recurrence and subsequent death from melanomas < 0.5 mm is a very rare event, and that quarterly follow-up for 3 years will yield very few events. Modification of current guideline recommendations are suggested to include a period of patient education concentrating on recognition of second primary tumours followed by rapid access to an expert opinion if required.