Tumour thickness and the site and time of first recurrence in cutaneous malignant melanoma (stage I).

A study was made of 326 patients first treated for clinical stage I cutaneous malignant melanoma by a wide excision (with or without split-skin graft) but no nodal dissection and who subsequently developed recurrence of their disease. Thick lesions recurred far more frequently than very thin lesions, although evidence of partial regression in very thin lesions conferred upon the latter a liability to metastasize. Thicker lesions first recurred predominantly in the vicinity of the scar of primary lesion excision whilst very thin lesions first recurred either at regional lymph nodes or at remote sites. The disease-free interval fell with increasing tumour thickness. As a result of this, local first recurrences developed more rapidly than remote first recurrences. The cumulative 10-year survival rate for patients with local first recurrences was, however, significantly higher than for patients with remote first recurrences, as the survival period after local first recurrence was considerably longer than after remote first recurrence. We conclude that tumour thickness is an easily measured, objective predictor of the site and time of first recurrence from melanoma. Thus, by facilitating early detection of first metastases, it may be possible to prolong survival time.