Challenges in sentinel node pathology in the era of adjuvant treatment.

BACKGROUND: With the approval of adjuvant therapy for stage III melanoma, accurate staging is more important than ever. Sentinel node biopsy (SNB) is an accurate staging tool, yet the presence of capsular nevi (CN) can lead to a false-positive diagnosis. PATIENTS AND METHODS: Retrospective analysis of the American Joint Committee on Cancer 7th edition stage IIIA melanoma patients who were treated at our institute between 2000 and 2015. SNB slides were reviewed for this study by an expert melanoma pathologist. RESULTS: Of 159 eligible patients, 14 originally diagnosed with metastatic melanoma merely had CN (8.8%). Another two merely had melanophages (1.3%). Thus, 10.1% of SNs were considered false positive after revision. In 12 patients, the SN tumor burden was originally reported as larger than 1 mm but turned out to be less than 1 mm. Four patients originally reported as SN tumor burden less than 1 mm before revision turned out to have larger than 1 mm. These patients might have been over- or undertreated in the current era of adjuvant therapy for stage III melanoma. CONCLUSIONS: Distinguishing metastatic melanoma from benign CN and melanophages can be a diagnostic challenge. We plead for an expert pathologists' review, especially when using the SNB + results to determine treatment consequences.

Isolated Limb Perfusion for Melanoma is Safe and Effective in Elderly Patients.

BACKGROUND: Data on isolated limb perfusion (ILP) in elderly melanoma patients are scarce. We aimed to evaluate the efficacy and safety of ILP in our institutional cohort of melanoma patients. METHODS: We performed retrospective analysis of stage IIIB/C melanoma patients who underwent ILP for melanoma in-transit metastases (ITMs) in our institution between 2000 and 2016. Normothermic ILP was performed with either melphalan or melphalan and tumor necrosis factor. Baseline and treatment characteristics, locoregional progression-free survival (LPFS) and melanoma-specific survival (MSS) were assessed and prognostic factors for response, recurrence, and survival were analyzed using univariable and multivariable analysis. RESULTS: Overall, 91 patients were included in this study. Based on the median age of 70 years, we split patients into younger and elderly groups. No differences in response rates were observed between age groups, with an overall response rate of 81% and complete response (CR) rate of 47%. LPFS did not differ between age groups, and median LPFS was 16 months for patients with a CR. Median MSS was 38 months and differed between younger (45 months) and elderly patients (18 months). Toxicity was generally mild and did not differ between age groups. Two patients (2.2%) suffered Wieberdink IV toxicity, while no patients required amputation because of severe toxicity. CR was prognostic for improved LPFS and MSS, while patients >70 years of age and patients with stage IIIC disease had a higher risk of melanoma-specific death. CONCLUSIONS: Because of its safety profile and high CR rates, ILP is a viable option for patients with bulky or multiple melanoma ITMs, including elderly (>70 years of age) patients.

Clinical prognostic markers in stage IIIC melanoma.

BACKGROUND: Although the EORTC 18071-trial has shown a clear survival benefit for adjuvant ipilimumab, accurately selecting patients for this toxic adjuvant therapy is important. We aimed to identify prognostic factors for death and disease recurrence in AJCC stage IIIC melanoma patients. PATIENTS AND METHODS: Retrospective analysis of patients who underwent lymph node dissection (LND) for stage IIIC melanoma in our institution between 2000 and 2016. Baseline characteristics, melanoma-specific survival (MSS), and disease-free survival (DFS) were assessed, and prognostic factors for recurrence and survival were analyzed using uni- and multivariable analysis. RESULTS: A total of 205 patients were included. Median follow-up was 20 months (interquartile range 11-43 months), median MSS was 28 months, and median DFS was 11 months. Five-year MSS was 33% and 5-year DFS was 23%. N3 (≥4 involved lymph nodes) and extracapsular extension (ECE) carried an increased risk of disease recurrence after LND and death by melanoma. Patients with both N3 and ECE had virtually no long-term survival. CONCLUSIONS: Although survival for patients with stage IIIC is poor in general, patients with both N3 disease and ECE constitute the group with the worst prognosis and should be considered for adjuvant therapy with ipilimumab or any other future effective adjuvant therapy (study).

Clinical Prognostic Markers in Stage IIIB Melanoma.

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).

External validation of the American Joint Committee on Cancer 8th edition melanoma staging system: who needs adjuvant treatment?

Now effective adjuvant therapy has arrived in melanoma, accurate staging and patient selection to optimize its risk/benefit ratio is crucial. The American Joint Committee on Cancer staging system is the most widely used and validated melanoma staging system, which recently released its 8th edition. We aimed to externally validate the prognostic and discriminatory ability for survival of the 8th edition compared to the 7th edition and evaluate prognostic factors. Prospective database of stage III melanoma (2000-2016). Prognostic factors for melanoma-specific survival and distant metastasis-free survival were analyzed. Survival differentiation of the 7th and 8th edition was assessed with log-rank tests and Cox proportional hazards models. Discriminatory ability was compared using the receiver operating characteristic and Akaike's Information Criterion. Six hundred forty patients were included (median follow-up 59 months). Median melanoma-specific survival was 138 months, distant metastasis-free survival 96 months. Age, Breslow thickness, ulceration of the primary tumor and number of positive lymph nodes (N) were independent prognostic parameters for distant metastasis-free survival and melanoma-specific survival. The 8th edition performed slightly better than the 7th edition in terms of survival discrimination but showed slightly worse distant metastasis-free survival and melanoma-specific survival differentiation between stage IIIA and IIIB. Sentinel node (SN) metastasis size cutoff of 1 mm differentiated survival in both 7th and 8th edition stage IIIA, showing excellent distant metastasis-free survival and melanoma-specific survival for patients with a SN metastasis size <1 mm. The 8th edition performed at least comparably, if not better than the 7th in terms of survival discrimination. However, survival in both 7th and 8th edition stage IIIA melanoma remains heterogeneous. EORTC SN tumor burden criteria can further stratify survival and help patient selection for adjuvant therapy.

Reversal of pre-existing NGFR-driven tumor and immune therapy resistance.

Melanomas can switch to a dedifferentiated cell state upon exposure to cytotoxic T cells. However, it is unclear whether such tumor cells pre-exist in patients and whether they can be resensitized to immunotherapy. Here, we chronically expose (patient-derived) melanoma cell lines to differentiation antigen-specific cytotoxic T cells and observe strong enrichment of a pre-existing NGFRhi population. These fractions are refractory also to T cells recognizing non-differentiation antigens, as well as to BRAF + MEK inhibitors. NGFRhi cells induce the neurotrophic factor BDNF, which contributes to T cell resistance, as does NGFR. In melanoma patients, a tumor-intrinsic NGFR signature predicts anti-PD-1 therapy resistance, and NGFRhi tumor fractions are associated with immune exclusion. Lastly, pharmacologic NGFR inhibition restores tumor sensitivity to T cell attack in vitro and in melanoma xenografts. These findings demonstrate the existence of a stable and pre-existing NGFRhi multitherapy-refractory melanoma subpopulation, which ought to be eliminated to revert intrinsic resistance to immunotherapeutic intervention.

Parotidectomy in patients with head and neck cutaneous melanoma with cervical lymph node involvement.

BACKGROUND: Parotidectomy in melanoma of the coronal scalp and face with clinically involved cervical lymph node metastasis is based on predicted cervical lymphatic drainage described by O'Brien. METHODS: In total, 40 parotidectomies with en bloc therapeutic neck dissection were retrospectively analyzed. RESULTS: Lymphatic spread of melanoma to the parotid lymph nodes was observed in 10 of 40 specimens (25%). Eight of the 10 parotid-positive patients developed a recurrence vs 17 of the 30 parotid-negative patients (P = 0.28). There were no differences in overall survival, melanoma-specific survival, and disease-free survival between the parotid-positive and parotid-negative patients. CONCLUSION: Although in this series no survival differences were found, parotidectomy still merits a sustained role in therapeutic neck dissection procedures to improve regional control and to prevent facial nerve damage after surgery for a second relapse from occult metastases in the parotid.

PET/CT surveillance detects asymptomatic recurrences in stage IIIB and IIIC melanoma patients: a prospective cohort study.

AJCC stage IIIB and IIIC melanoma patients are at risk for disease relapse or progression. The advent of effective systemic therapies has made curative treatment of progressive disease a possibility. As resection of oligometastatic disease can confer a survival benefit and as immunotherapy is possibly most effective in a low tumor load setting, there is a likely benefit to early detection of progression. The aim of this pilot study was to evaluate a PET/computed tomography (CT) surveillance schedule for resected stage IIIB and IIIC melanoma. From 1-2015, stage IIIB and IIIC melanoma patients at our institution underwent 6-monthly surveillance with PET/CT, together with 3-monthly S100B assessment. When symptoms or elevated S100B were detected, an additional PET/CT was performed. Descriptive statistics were used to evaluate outcomes for this surveillance schedule. Fifty-one patients were followed up, 27 patients developed a recurrence before surveillance imaging, five were detected by an elevated S100B, and one patient was not scanned according to protocol. Eighteen patients were included. Thirty-two scans were acquired. Eleven relapses were suspected on PET/CT. Ten scans were true positive, one case was false positive, and one case was false negative. All recurrences detected by PET/CT were asymptomatic at that time, with a normal range of S100B. The number of scans needed to find one asymptomatic relapse was 3.6. PET/CT surveillance imaging seems to be an effective strategy for detecting asymptomatic recurrence in stage IIIB and IIIC melanoma patients in the first year after complete surgical resection.

Blue dye can be safely omitted in most sentinel node procedures for melanoma.

Sentinel node biopsy is a widely used staging procedure in melanoma. It is usually performed using the triple technique: lymphatic mapping after injection of a radiopharmaceutical, blue dye injection, and the use of a gamma probe. Blue dye offers visual confirmation of the location of the sentinel lymph node (SN). There are some disadvantages such as blurring of the surgical field, skin coloring, and possible anaphylactic reactions. We aimed to answer the question whether patent blue is truly necessary for correct intraoperative identification of the SN. One day preoperatively, lymphoscintigraphy (with or without single-photon emission computed tomography with integrated computed tomography) is performed and the location of the SN is marked on the skin. Perioperatively, patent blue is injected around the tumor. A handheld gamma-ray detection probe is used to determine the location of the incision and detect the SN during the operation. SNs are pursued in all regions indicated by imaging. In only six of the 681 patients (0.9%) a blue, not radioactive, sentinel node was removed. In one of them (0.15%), this was the only node excised. None of these lymph nodes harbored metastases. This study suggests that blue dye has no additional value in finding the sentinel node and is of low significance in detecting metastases. Therefore, blue dye can be safely omitted from the standardized triple technique. It may be useful in selected cases according to the surgeon's discretion.