Time-varying pattern of recurrence risk for localized melanoma in China

Abstract

Background: Acral and mucosal melanomas are rarely seen in Caucasians but common in China. There are limited data on the recurrence characteristics for these patients. This study aimed to identify the recurrence pattern for localized melanoma in China, especially acral and mucosal subtypes.

Methods: Patients with localized melanoma who underwent radical resection between January 1999 and December 2014 in southern China were retrospectively reviewed. Survival and annual recurrence hazard were analyzed by Kaplan-Meier method and hazard function, respectively.

Results: Totally, 1012 patients were included (acral melanoma 400; chronic sun-induced damage (CSD)/non-CSD melanoma 314; mucosal melanoma 298). Recurrence was recorded in 808 patients (localized 14.1%; regional 29.6%, and distant 56.3%). Mucosal melanoma had local and M1c stage recurrence more frequently than cutaneous melanoma, but less frequent regional node relapse. There was no difference in recurrent site distribution between acral and CSD/non-CSD melanoma. The annual recurrence hazard curve for the entire cohort showed a double-peaked pattern with the first major peak in the second year after surgery and the second peak near the seventh year. Mucosal melanoma had a higher recurrence risk than cutaneous melanoma. Acral melanoma had a lower flat recurrence peak than CSD/non-CSD melanoma. Tumor thickness > 4.0 mm, ulceration, positive regional nodes, and wound infection were associated with a higher recurrence risk in cutaneous melanoma. Adjuvant therapy reduced the recurrence risk of cutaneous melanoma but not of mucosal melanoma.

Conclusions: This is a large cohort about the rule of recurrence risk in acral and mucosal melanoma and will provide an initial framework for development of surveillance and adjuvant strategy for Chinese melanoma patients.

Keywords: Chinese population; Melanoma; Recurrence hazard.

Fig. 1

Comparisons of the frequencies of metastatic sites between cutaneous and mucosal melanoma. The most common metastasis site of mucosal melanoma was other distant sites besides the lung, skin, or soft tissue, but for cutaneous melanoma, the most common site was the skin/soft tissue. P value refers to the chi-square test of the proportion of the metastasis sites for the two groups

Fig. 2

Kaplan–Meier curves for recurrence-free survival (RFS) in 714 patients with cutaneous melanoma analyzed by clinicopathological factors. a RFS analysis by primary site; b RFS analysis by tumor thickness; c RFS analysis by ulceration; d RFS analysis by regional lymph node metastasis; e RFS analysis by wound infection; and f RFS analysis by adjuvant therapy

Fig. 3

Recurrent hazard curve for the whole cohort

Fig. 4

Recurrence hazard analysis according to clinicopathological characteristics. a pathological types; b primary tumor thickness of cutaneous melanoma; c: ulceration of primary lesion in cutaneous melanoma; d regional lymph node status for cutaneous melanoma; e wound infection of cutaneous melanoma; f adjuvant therapy in cutaneous melanoma; g adjuvant therapy in mucosal melanoma