Background: Locoregional treatment is often insufficient to guarantee long-term disease-free survival (DFS) in American Joint Committee on Cancer stage IIIB melanoma, and, in order to improve survival, effective neoadjuvant and adjuvant strategies are needed . Selecting patients for these strategies requires risk stratification, for which clinical and molecular biomarkers can be used. We aimed to detect clinical biomarkers to identify high-risk stage IIIB melanoma patients.
Patients and methods: We performed retrospective analysis of stage IIIB melanoma patients who underwent lymph node dissection (LND) in our institution between 2000 and 2015. Sentinel node-positive patients with ulcerated primary tumors, as well as patients with clinically detectable nodal metastasis with non-ulcerated tumors, were included. Baseline characteristics, melanoma-specific survival (MSS), and DFS were assessed, and prognostic factors for recurrence and survival were analyzed, using univariate and multivariate analysis.
Results: Overall, 250 patients were included. Median follow-up was 52 months (interquartile range 29-108 months), median MSS was 141 months, and median DFS was 36 months. Five- and 10-year MSS was 59 and 52 %, respectively, and 5- and 10-year DFS was 47 and 41 %, respectively. Age >50 years, Breslow thickness >2 versus ≤2 mm, and N2 versus N1 disease all carried an increased risk of death by melanoma. Age >50 years and extracapsular extension carried an increased risk of disease recurrence after LND.
Conclusions: Age >50 years, Breslow thickness >2 mm and N2 versus N1 disease are prognostic factors for poor survival in stage IIIB melanoma. These characteristics can be used to further stratify risk of death by melanoma in this already high-risk patient population and to help select the appropriate population for adjuvant therapy (trials).