Histopathologic regression in patients with primary cutaneous melanoma undergoing sentinel lymph node biopsy is associated with favorable survival and, after metastasis, with improved progression-free survival on immune checkpoint inhibitor therapy: A single-institutional cohort study.

BACKGROUND: Histopathologic regression of cutaneous melanoma is considered a favorable prognostic factor, but its significance in clinical practice remains controversial. OBJECTIVE: To investigate the prognostic importance of regression in patients with primary cutaneous melanoma undergoing sentinel lymph node (SLN) biopsy and to assess its significance in patients progressing to an unresectable stage requiring systemic therapy. METHODS: We retrospectively reviewed patients with newly diagnosed melanoma undergoing SLN biopsy between 2010 and 2015 and available information on histopathologic regression (n = 1179). Survival data and associations of clinical variables with SLN status were assessed. RESULTS: Patients with regressive melanoma showed favorable relapse-free (hazard ratio [HR], 0.52; P = .00013), distant metastasis-free (HR, 0.56; P = .0020), and melanoma-specific survival (HR, 0.35; P = .00053). Regression was associated with negative SLN (odds ratio, 0.48; P = .0077). In patients who progressed to an unresectable stage, regression was associated with favorable progression-free survival under immune checkpoint inhibition (HR, 0.43; P = .031) but not under targeted therapy (HR, 1.14; P = .73) or chemotherapy (HR, 3.65; P = .0095). LIMITATIONS: Retrospective, single-institutional design. CONCLUSIONS: Regression of cutaneous melanoma is associated with improved prognosis in patients eligible for SLN biopsy as well as in patients with unresectable disease receiving systemic therapy with immune checkpoint inhibitors.

Absolute and relative differential blood count predicts survival of AJCC stage I-II melanoma patients scheduled for sentinel lymph node biopsy.

BACKGROUND/OBJECTIVES: Elevated neutrophil-to-lymphocyte ratio (NLR) in peripheral blood is associated with poor overall survival (OS) in metastatic melanoma patients receiving immunotherapy. However, the impact of peripheral blood cells in patients undergoing sentinel lymph node biopsy (SLNB) is still unclear. This study was intended to characterize the impact of peripheral blood leukocytic cells on overall survival (OS) in melanoma patients undergoing SLNB. METHODS: A total of 1412 AJCC stage I-II melanoma patients scheduled for SLNB at a single institution in the period 2010-2015 with available perioperative blood tests were randomly assigned to two independent cohorts. Associations of peripheral blood leukocytes with OS were analysed using Kaplan-Meier estimator and multivariate Cox proportional hazards model. RESULTS: NLR >4.26, absolute neutrophil count >5800/µL, relative neutrophil count >69.7% and relative lymphocyte count ≤ 17.5% were significantly associated with reduced OS in both cohorts. Absolute monocytes >810/µL, absolute eosinophils ≤200/µL, relative monocytes >6.6%, relative eosinophils ≤2.7% and relative basophils ≤0.6% were significantly associated with reduced OS in one cohort each. On multivariate analysis, a combined score including absolute levels of neutrophils, lymphocytes, monocytes and eosinophils was significantly associated with OS in both cohorts. The hazard ratio of patients with a risk score of 3-4 was 5.42 (95% confidence interval: 1.52-19.42, P = 0.0094) in cohort 1 and 9.42 (2.06-43.06, P = 0.0038) in cohort 2, respectively. CONCLUSIONS: We conclude that peripheral blood leukocytes are independently associated with OS in stage I-II melanoma patients and should be considered as prognostic markers in these patients. Eosinophils and basophils deserve more attention in future investigations.