High response rate to PD-1 blockade in desmoplastic melanomas.

Desmoplastic melanoma is a rare subtype of melanoma characterized by dense fibrous stroma, resistance to chemotherapy and a lack of actionable driver mutations, and is highly associated with ultraviolet light-induced DNA damage. We analysed sixty patients with advanced desmoplastic melanoma who had been treated with antibodies to block programmed cell death 1 (PD-1) or PD-1 ligand (PD-L1). Objective tumour responses were observed in forty-two of the sixty patients (70%; 95% confidence interval 57-81%), including nineteen patients (32%) with a complete response. Whole-exome sequencing revealed a high mutational load and frequent NF1 mutations (fourteen out of seventeen cases) in these tumours. Immunohistochemistry analysis from nineteen desmoplastic melanomas and thirteen non-desmoplastic melanomas revealed a higher percentage of PD-L1-positive cells in the tumour parenchyma in desmoplastic melanomas (P = 0.04); these cells were highly associated with increased CD8 density and PD-L1 expression in the tumour invasive margin. Therefore, patients with advanced desmoplastic melanoma derive substantial clinical benefit from PD-1 or PD-L1 immune checkpoint blockade therapy, even though desmoplastic melanoma is defined by its dense desmoplastic fibrous stroma. The benefit is likely to result from the high mutational burden and a frequent pre-existing adaptive immune response limited by PD-L1 expression.

Oncologic Outcomes of Multi-Institutional Minimally Invasive Inguinal Lymph Node Dissection for Melanoma Compared with Open Inguinal Dissection in the Second Multicenter Selective Lymphadenectomy Trial (MSLT-II).

BACKGROUND: Minimally invasive inguinal lymphadenectomy (MILND) is safe and feasible, but limited data exist regarding oncologic outcomes. METHODS: This study performed a multi-institutional retrospective cohort analysis of consecutive MILND performed for melanoma between January 2009 and June 2016. The open ILND (OILND) comparative cohort comprised patients enrolled in the second Multicenter Selective Lymphadenectomy Trial (MSLT-II) between December 2004 and March 2014.The pre-defined primary end point was the same-basin regional nodal recurrence, calculated using properties of binomial distribution. Time to events was calculated using the Kaplan-Meier method. The secondary end points were overall survival, progression-free survival, melanoma-specific survival (MSS), and distant metastasis-free survival (DMFS). RESULTS: For all the patients undergoing MILND, the same-basin regional recurrence rate was 4.4 % (10/228; 95 % confidence interval [CI], 2.1-7.9 %): 8.2 % (4/49) for clinical nodal disease and 3.4 % (6/179) for patients with a positive sentinel lymph node (SLN) as the indication. For the 288 patients enrolled in MSLT-II who underwent OILND for a positive SLN, 17 (5.9 %) had regional node recurrence as their first event. After controlling for ulceration, positive LN count and positive non-SLNs at the time of lymphadenectomy, no difference in OS, PFS, MSS or DMFS was observed for patients with a positive SLN who underwent MILND versus OILND. CONCLUSION: This large multi-institutional experience supports the oncologic safety of MILND for melanoma. The outcomes in this large multi-institutional experience of MILND compared favorably with those for an OILND population during similar periods, supporting the oncologic safety of MILND for melanoma.

Preoperative Ultrasound Assessment of Regional Lymph Nodes in Melanoma Patients Does not Provide Reliable Nodal Staging: Results From a Large Multicenter Trial.

OBJECTIVE: To assess whether preoperative ultrasound (US) assessment of regional lymph nodes in patients who present with primary cutaneous melanoma provides accurate staging. BACKGROUND: It has been suggested that preoperative US could avoid the need for sentinel node (SN) biopsy, but in most single-institution reports, the sensitivity of preoperative US has been low. METHODS: Preoperative US data and SNB results were analyzed for patients enrolled at 20 centers participating in the screening phase of the second Multicenter Selective Lymphadenectomy Trial. Excised SNs were histopathologically assessed and considered positive if any melanoma was seen. RESULTS: SNs were identified and removed from 2859 patients who had preoperative US evaluation. Among those patients, 548 had SN metastases. US was positive (abnormal) in 87 patients (3.0%). Among SN-positive patients, 39 (7.1%) had an abnormal US. When analyzed by lymph node basin, 3302 basins were evaluated, and 38 were true positive (1.2%). By basin, the sensitivity of US was 6.6% (95% confidence interval: 4.6-8.7) and the specificity 98.0% (95% CI: 97.5-98.5). Median cross-sectional area of all SN metastases was 0.13 mm2; in US true-positive nodes, it was 6.8 mm2. US sensitivity increased with increasing Breslow thickness of the primary melanoma (0% for ≤1 mm thickness, 11.9% for >4 mm thickness). US sensitivity was not significantly greater with higher trial center volume or with pre-US lymphoscintigraphy. CONCLUSION: In the MSLT-II screening phase population, SN tumor volume was usually too small to be reliably detected by US. For accurate nodal staging to guide the management of melanoma patients, US is not an effective substitute for SN biopsy.

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma.

BACKGROUND: Sentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear. METHODS: In an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis. RESULTS: Immediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in the per-protocol analysis. In the per-protocol analysis, the mean (±SE) 3-year rate of melanoma-specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log-rank test) at a median follow-up of 43 months. The rate of disease-free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log-rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log-rank test); these results must be interpreted with caution. Nonsentinel-node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group. CONCLUSIONS: Immediate completion lymph-node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma-specific survival among patients with melanoma and sentinel-node metastases. (Funded by the National Cancer Institute and others; MSLT-II ClinicalTrials.gov number, NCT00297895 .).

Regional Node Basin Recurrence in Melanoma Patients: More Common After Node Dissection for Macroscopic Rather than Clinically Occult Nodal Disease.

BACKGROUND: Recommended treatment for patients with sentinel lymph node (SLN)-positive melanoma has recently changed. Randomized trials demonstrated equivalent survival with close observation versus completion lymph node dissection (CLND), but increased regional node recurrence. We evaluated factors related to in-basin nodal recurrence after lymphadenectomy (LND) for SLN-positive or macroscopic nodal metastases. METHODS: An institutional database and the first Multicenter Selective Lymphadenectomy Trial (MSLT-I) were analyzed independently. Exclusions were multiple primaries, multi-basin involvement, or in-transit metastases. Patient demographics, primary tumor thickness and ulceration, lymph nodes retrieved, and use of adjuvant radiotherapy were analyzed. Multivariate analyses were performed to determine factors predicting in-basin nodal recurrence (significance p ≤ 0.05). RESULTS: The retrospective cohort (577 patients) showed an in-basin failure rate of 6.6% after CLND for a positive SLN and 13.1% after LND for palpable disease (p = 0.001). This recurrence risk persisted after adjustment for patient, tumor, and LND factors [hazard ratio (HR) 2.32; p = 0.004]. In the MSLT-I cohort (326 patients), the failure rate after CLND following SLNB was 6.2%, but 10.1% after LND for palpable recurrence in observation patients. After adjustment for other factors, macroscopic disease was associated with an increased risk of recurrence after LND (HR 2.24; p = 0.05). CONCLUSION: After LND for melanoma, in-basin recurrence is infrequent, but a clinically significant fraction will fail. Failure is less likely if dissection is performed for clinically occult disease. Further research is warranted to evaluate the long-term regional control and quality of life associated with nodal basin observation, which has now become standard practice.

Final trial report of sentinel-node biopsy versus nodal observation in melanoma.

BACKGROUND: Sentinel-node biopsy, a minimally invasive procedure for regional melanoma staging, was evaluated in a phase 3 trial. METHODS: We evaluated outcomes in 2001 patients with primary cutaneous melanomas randomly assigned to undergo wide excision and nodal observation, with lymphadenectomy for nodal relapse (observation group), or wide excision and sentinel-node biopsy, with immediate lymphadenectomy for nodal metastases detected on biopsy (biopsy group). Results No significant treatment-related difference in the 10-year melanoma-specific survival rate was seen in the overall study population (20.8% with and 79.2% without nodal metastases). Mean (± SE) 10-year disease-free survival rates were significantly improved in the biopsy group, as compared with the observation group, among patients with intermediate-thickness melanomas, defined as 1.20 to 3.50 mm (71.3 ± 1.8% vs. 64.7 ± 2.3%; hazard ratio for recurrence or metastasis, 0.76; P=0.01), and those with thick melanomas, defined as >3.50 mm (50.7 ± 4.0% vs. 40.5 ± 4.7%; hazard ratio, 0.70; P=0.03). Among patients with intermediate-thickness melanomas, the 10-year melanoma-specific survival rate was 62.1 ± 4.8% among those with metastasis versus 85.1 ± 1.5% for those without metastasis (hazard ratio for death from melanoma, 3.09; P<0.001); among patients with thick melanomas, the respective rates were 48.0 ± 7.0% and 64.6 ± 4.9% (hazard ratio, 1.75; P=0.03). Biopsy-based management improved the 10-year rate of distant disease-free survival (hazard ratio for distant metastasis, 0.62; P=0.02) and the 10-year rate of melanoma-specific survival (hazard ratio for death from melanoma, 0.56; P=0.006) for patients with intermediate-thickness melanomas and nodal metastases. Accelerated-failure-time latent-subgroup analysis was performed to account for the fact that nodal status was initially known only in the biopsy group, and a significant treatment benefit persisted. CONCLUSIONS: Biopsy-based staging of intermediate-thickness or thick primary melanomas provides important prognostic information and identifies patients with nodal metastases who may benefit from immediate complete lymphadenectomy. Biopsy-based management prolongs disease-free survival for all patients and prolongs distant disease-free survival and melanoma-specific survival for patients with nodal metastases from intermediate-thickness melanomas. (Funded by the National Cancer Institute, National Institutes of Health, and the Australia and New Zealand Melanoma Trials Group; ClinicalTrials.gov number, NCT00275496.).

Tumour-induced immune modulation of sentinel lymph nodes.

Sentinel lymph nodes (SLNs), being the first nodes to receive lymph from a primary tumour and the preferential site of initial tumour metastases, are intensively exposed to the bioactive products of tumour cells and other associated cells. This makes them ideal for studies of the factors that determine selective tissue susceptibility to metastases. We postulate that tumour-induced immune modulation of SLNs facilitates lymph-node metastases by inhibiting the generation of tumour-specific cytotoxic T cells that are active against tumour cells of primary and metastatic melanomas. Immune modulation of the lymph nodes can be reversed by granulocyte/macrophage colony-stimulating factor (GM-CSF), a finding that has implications for the future therapy of lymph-node metastases.

Keratoacanthoma and squamous cell carcinoma are distinct from a molecular perspective.

Keratoacanthoma is a controversial entity. Some consider keratoacanthoma as a variant of squamous cell carcinoma, whereas others see it as a distinct self-resolving squamoproliferative lesion. Our objective is to examine the relationship of keratoacanthoma with squamous cell carcinoma and normal skin by using DNA microarrays. DNA microarray studies were performed on formalin-fixed and paraffin-embedded blocks from ten cases of actinic keratoacanthoma utilizing the U133plus2.0 array. These results were compared with our previously developed microarray database of ten squamous cell carcinoma and ten normal skin samples. Keratoacanthoma demonstrated 1449 differentially expressed genes in comparison with squamous cell carcinoma (>5-fold change: P<0.01) with 908 genes upregulated and 541 genes downregulated. Keratoacanthoma showed 2435 differentially expressed genes in comparison with normal skin (>5-fold change: P<0.01) with 1085 genes upregulated and 1350 genes downregulated. The most upregulated genes, comparing keratoacanthoma with normal skin included MALAT1, S100A8, CDR1, TPM4, and CALM1. The most downregulated genes included SCGB2A2, DCD, THRSP, ADIPOQ, adiponectin, and ADH1B. The molecular biological pathway analysis comparing keratoacanthoma with normal skin showed that cellular development, cellular growth and proliferation, cell death/apoptosis, and cell cycle pathways are prominently involved in the pathogenesis of keratoacanthoma. The most enriched canonical pathways were clathrin-mediated endocytosis signaling, molecular mechanisms of cancer and integrin signaling. The distinctive gene expression profile of keratoacanthoma reveals that it is molecularly distinct from squamous cell carcinoma. The molecular pathways and genes differentially expressed in comparing keratoacanthoma with normal skin suggest that keratoacanthoma is a neoplasm that can regress due to upregulation of the cell death/apoptosis pathway.

Age as a predictor of sentinel node metastasis among patients with localized melanoma: an inverse correlation of melanoma mortality and incidence of sentinel node metastasis among young and old patients.

PURPOSE: We have previously reported that older patients with clinical stage I and II primary cutaneous. Melanoma had lower survival rates compared to younger patients. We postulated that the incidence of nodal metastasis would therefore be higher among older melanoma patients. METHODS: The expanded American Joint Committee on Cancer melanoma staging database contains a cohort of 7,756 melanoma patients who presented without clinical evidence of regional lymph node or distant metastasis and who underwent a sentinel node biopsy procedure as a component of their staging assessment. RESULTS: Although older patients had primary melanoma features associated with more aggressive biology, we paradoxically observed a significant decrease in the incidence of sentinel node metastasis as patient age increased. Overall, the highest incidence of sentinel node metastasis was 25.8 % in patients under 20 years of age, compared to 15.5 % in patients 80 years and older (p < 0.001). In contrast, 5-year mortality rates for clinical stage II patients ranged from a low of 20 % for those 20-40 years of age up to 38 % for those over 70 years of age. Patient age was an independent predictor of sentinel node metastasis in a multifactorial analysis (p < 0.001). CONCLUSIONS: Patients with clinical stage I and II melanoma under 20 years of age had a higher incidence of sentinel lymph node metastasis but, paradoxically, a more favorable survival outcome compared to all other age groups. In contrast, patients >70 years had the most aggressive primary melanoma features and a higher mortality rate compared to all other age groups but a lower incidence of sentinel lymph node metastasis.

Smoking Status and Survival in Patients With Early-Stage Primary Cutaneous Melanoma.

Importance: While smoking is associated with a decreased incidence of cutaneous melanoma, the association of smoking with melanoma progression and death is not well defined. Objective: To determine the association of smoking with survival in patients with early-stage primary cutaneous melanoma. Design, Setting, and Participants: This cohort study performed a post hoc analysis of data derived from the randomized, multinational first and second Multicenter Selective Lymphadenectomy Trials (MSLT-I and MSLT-II). Participants were accrued for MSLT-I from January 20, 1994, to March 29, 2002; MSLT-II, from December 21, 2004, to March 31, 2014. Median follow-up was 110.0 (IQR, 53.4-120.0) months for MSLT-I and 67.6 (IQR, 25.8-110.2) months for MSLT-II. Patients aged 18 to 75 years with clinical stages I or II melanoma with a Breslow thickness of 1.00 mm or greater or Clark level IV to V and available standard prognostic and smoking data were included. Analyses were performed from October 4, 2022, to March 31, 2023. Exposure: Current, former, and never smoking. Main Outcomes and Measures: Melanoma-specific survival of patients with current, former, and never smoking status was assessed for the entire cohort and for nodal observation and among subgroups with sentinel lymph node biopsy (SLNB)-negative and SLNB-positive findings. Results: Of 6279 included patients, 3635 (57.9%) were men, and mean (SD) age was 52.7 (13.4) years. The most common tumor location was an extremity (2743 [43.7%]), and mean (SD) Breslow thickness was 2.44 (2.06) mm. Smoking status included 1077 (17.2%) current, 1694 (27.0%) former, and 3508 (55.9%) never. Median follow-up was 78.4 (IQR, 30.5-119.6) months. Current smoking was associated with male sex, younger age, trunk site, thicker tumors, tumor ulceration, and SLNB positivity. Current smoking was associated with a greater risk of melanoma-associated death by multivariable analysis for the entire study (hazard ratio [HR], 1.48 [95% CI, 1.26-1.75]; P < .001). Former smoking was not. The increased risk of melanoma-specific mortality associated with current smoking was greatest for patients with SLNB-negative melanoma (HR, 1.85 [95% CI, 1.35-2.52]; P < .001), but also present for patients with SLNB-positive melanoma (HR, 1.29 [95% CI, 1.04-1.59]; P = .02) and nodal observation (HR, 1.68 [95% CI, 1.09-2.61]; P = .02). Smoking at least 20 cigarettes/d doubled the risk of death due to melanoma for patients with SLNB-negative disease (HR, 2.06 [95% CI, 1.36-3.13]; P < .001). Conclusions and Relevance: The findings of this cohort study suggest that patients with clinical stage I and II melanoma who smoked had a significantly increased risk of death due to melanoma. Smoking status should be assessed at time of melanoma diagnosis and may be considered a risk factor for disease progression.

Age as a prognostic factor in patients with localized melanoma and regional metastases.

BACKGROUND: We postulated that the worse prognosis of melanoma with advancing age reflected more aggressive tumor biology and that in younger patients the prognosis would be more favorable. MATERIALS AND METHODS: The expanded AJCC melanoma staging database contained 11,088 patients with complete data for analysis, including mitotic rate. RESULTS: With increasing age by decade, primary melanomas were thicker, exhibited higher mitotic rates, and were more likely to be ulcerated. In a multivariate analysis of patients with localized melanoma, thickness and ulceration were highly significant predictors of outcome at all decades of life (except for patients younger than 20 years). Mitotic rate was significantly predictive in all age groups except patients <20 and >80 years. For patients with stage III melanoma, there were four independent variables associated with patient survival: number of nodal metastases, patient age, ulceration, and mitotic rate. Patients younger than 20 years of age had primary tumors with slightly more aggressive features, a higher incidence of sentinel lymph node metastasis, but, paradoxically, more favorable survival than all other age groups. In contrast, patients >70 years old had primary melanomas with the most aggressive prognostic features, were more likely to be head and neck primaries, and were associated with a higher mortality rate than the other age groups. Surprisingly, however, these patients had a lower rate of sentinel lymph node metastasis per T stage. Among patients between the two age extremes, clinicopathologic features and survival tended to be more homogeneous. CONCLUSIONS: Melanomas in patients at the extremes of age have a distinct natural history.

Differential gene expression profiling of primary cutaneous melanoma and sentinel lymph node metastases.

Limited understanding of molecular mechanisms of metastasis in melanoma contributes to the absence of effective treatments. Increased knowledge of alterations in genes that underpin critical molecular events that lead to metastasis is essential. We have investigated the gene expression profiles of primary melanomas and melanoma metastases in sentinel lymph nodes. A total of 19 samples (10 primary melanomas and 9 sentinel lymph node metastases) were evaluated. Melanoma cells were dissected from tissue blocks. Total mRNA was isolated, amplified, and labeled using an Ambion Recover All Total Nucleic Acid Isolation kit, Nu-GEN WT-Ovation formalin-fixed, paraffin-embedded RNA Amplification System, and FL-Ovation cDNA Biotin Module V2, respectively. Samples were hybridized to the Affymetrix Gene Chip Human U133 Plus 2.0 Array. Data were analyzed using Partek Genomics Suite Version 6.4. Genes selected showed ≥2-fold difference in expression and P<5.00E-2. Validation studies used standard immunohistochemical assays. Hierarchical clustering disclosed two distinct groups: 10 primary melanomas and 9 sentinel lymph node metastases. Gene expression analysis identified 576 genes that showed significant differential expression. Most differences reflected decreased gene expression in metastases relative to primaries. Reduced gene expression in primaries was less frequent and less dramatic. Genes significantly increased or decreased in sentinel lymph node metastases were active in cell adhesion/structural integrity, tumor suppression, cell cycle regulation, and apoptosis. Validation studies indicate that MAGEC1 (melanoma antigen family C1) and FCRL1 (Fc receptor-like 1) are involved in melanoma progression. There are striking differential gene expression patterns between primary and nodally metastatic melanomas. Similar findings were seen with autologous paired primary melanomas and sentinel lymph node metastases, supporting involvement of these gene alterations in evolution of metastases. With further study, it may be possible to determine the exact sequence of molecular events that underlie melanoma metastases.

Exome sequencing-based copy-number variation and loss of heterozygosity detection: ExomeCNV.

MOTIVATION: The ability to detect copy-number variation (CNV) and loss of heterozygosity (LOH) from exome sequencing data extends the utility of this powerful approach that has mainly been used for point or small insertion/deletion detection. RESULTS: We present ExomeCNV, a statistical method to detect CNV and LOH using depth-of-coverage and B-allele frequencies, from mapped short sequence reads, and we assess both the method's power and the effects of confounding variables. We apply our method to a cancer exome resequencing dataset. As expected, accuracy and resolution are dependent on depth-of-coverage and capture probe design. AVAILABILITY: CRAN package 'ExomeCNV'. CONTACT: fsathira@fas.harvard.edu; snelson@ucla.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Metastasectomy for distant metastatic melanoma: analysis of data from the first Multicenter Selective Lymphadenectomy Trial (MSLT-I).

BACKGROUND: For stage IV melanoma, systemic medical therapy (SMT) is used most frequently; surgery is considered an adjunct in selected patients. We retrospectively compared survival after surgery with or without SMT versus SMT alone for melanoma patients developing distant metastases while enrolled in the first Multicenter Selective Lymphadenectomy Trial. METHODS: Patients were randomized to wide excision and sentinel node biopsy, or wide excision and nodal observation. We evaluated recurrence site, therapy (selected by treating clinician), and survival after stage IV diagnosis. RESULTS: Of 291 patients with complete data for stage IV recurrence, 161 (55 %) underwent surgery with or without SMT. Median survival was 15.8 versus 6.9 months, and 4-year survival was 20.8 versus 7.0 % for patients receiving surgery with or without SMT versus SMT alone (p < 0.0001; hazard ratio 0.406). Surgery with or without SMT conferred a survival advantage for patients with M1a (median > 60 months vs. 12.4 months; 4-year survival 69.3 % vs. 0; p = 0.0106), M1b (median 17.9 vs. 9.1 months; 4-year survival 24.1 vs. 14.3 %; p = 0.1143), and M1c (median 15.0 vs. 6.3 months; 4-year survival 10.5 vs. 4.6 %; p = 0.0001) disease. Patients with multiple metastases treated surgically had a survival advantage, and number of operations did not reduce survival in the 67 patients (42 %) who had multiple surgeries for distant melanoma. CONCLUSIONS: Our findings suggest that over half of stage IV patients are candidates for resection and exhibit improved survival over patients receiving SMT alone, regardless of site and number of metastases. We have begun a multicenter randomized phase III trial comparing surgery versus SMT as initial treatment for resectable distant melanoma.