Relapse patterns in patients with local and regional cutaneous melanoma.

BACKGROUND: The differences in features and risk factors for recurrence after definitive surgical excision are yet to be determined. The aim of this study was to understand these factors influencing recurrence patterns with local and regional disease in these patients.

METHODS: A total of 365 relapsed patients, of whom 196 presented with local disease (stage I-II) and 169 with regional disease (stage III), were investigated in this retrospective study.

RESULTS: The median time to initial recurrence for stage I-II and stage III patients was 22.3 and 13.4 months, respectively. Stage III patients were found to have higher Clark levels (p = 0.0001) and thicker lesions (p = 0.0001), and they were more significantly associated with the absence of tumor-infiltrating lymphocytes (p = 0.02) than stage I-II patients. Stage III patients were more significantly associated with recurrences compared to the stage I-II patients (p = 0.0001). Locoregional relapses were significantly associated with stage I-II melanomas, whereas majority of the distant metastases occurred in stage III patients (p = 0.01). Pulmonary metastasis was most frequently observed and the distribution of the sites for distant metastases was similar in both groups of the patients. On univariate analysis, male sex, increased tumor depth, presence of ulceration, nodular histopathology, higher Clark level, higher mitotic rate, and presence of lymphovascular invasions were found to predict shorter time to relapse for stage I-II patients; whereas only nodular pathology, presence of ulceration, and high mitotic rate were found to be associated with poor relapse-free survival in stage III patients. However, on multivariate analysis, only mitotic rate maintained its significance for both clinical staging groups.

CONCLUSION: Potential differences among early-stage melanoma patients, who developed recurrence, were noted and mitotic rate was found as the single significant prognostic factor for recurrence in both stage I-II and III patients.