Prognostic Effect of Primary Tumor Characteristics in Metastatic Melanoma

Abstract

ABSTRACT Aim: Prognostic effect of pathological and clinical parameters of the primary tumor is well-defined in localized melanoma. In this study we analyzed the effect of these parameters on survival duration in metastatic melanoma. Methods: Records of cutaneous metastatic melanoma patients diagnosed between 2006 - 2013 in our center were reviewed. Patients with pathological data of the primary melanoma lesion were included in the study. We analyzed the effect of pathological and clinical parameters on disease-specific survival (DSS). DSS was measured from diagnosis of metastatic melanoma to death. Results: 140 patients were included in the study. At a median follow-up duration of 28 months, 88 deaths were observed. DSS of the patient population was 16 months (95% CI: 13.3–18.7). Male patients had a shorter median DSS (14.4 vs. 19.4 months, p: 0.046). DSS was similar in patients aged under and over 60 years. Presence of ulceration of the primary lesion was associated with worse median survival duration (15 vs. 22.3 months, p: 0.006). Mitotic count of less than 5/mm2 was associated with longer median DSS compared with 5 or more mitoses/mm2 (22.3 vs. 13.2, p: 0.013). Breslow thickness (≤2 mm vs. >2 mm) was not found to have a prognostic effect; however, patients with regional lymph node metastases at the time of diagnosis had shorter median DSS duration (13.5 vs. 23 months, p: 0.035). Localization of the primary tumor, histological subtype and presence of regression were not associated with DSS in metastatic melanoma. In multivariate analysis, presence of ulceration (HR: 2.54, 95%CI: 1.2–5.3), and mitotic count of 5 or more (HR: 2.43, 95%CI: 1.1–5.4) were associated with decreased DSS. Conclusions: Presence of ulceration, high mitotic count (≥5/mm2) and presence of regional lymph node metastases at the time of diagnosis are among the well-known prognostic factors in localized melanoma. Our results support that these factors may portend poor prognosis also in metastatic melanoma. These parameters may be associated with tumor biology and may indicate more aggressive disease. Disclosure: All authors have declared no conflicts of interest.