Faculty Bibliography

BACKGROUND:Vulvar squamous cell carcinoma (vSCC) is a rare tumor with a good prognosis when treated at a localized stage. However, once regional/distant metastasis occurs, vSCC can be rapidly fatal. Thus, it is important to identify tumor prognostic features so that high-risk cases can be prioritized for further diagnostic workup and treatment. OBJECTIVE:To estimate the risk of regional/distant metastasis at presentation and sentinel lymph node status for vSCC based on histopathologic characteristics. METHODS:A retrospective cohort study of 15,188 adult vSCC cases from the National Cancer Database diagnosed from 2012 to 2019. RESULTS:We provide specific estimates of the risk of clinically positive nodes and metastatic disease at presentation and sentinel lymph node positivity according to tumor size, moderate/poor tumor differentiation, and lymph-vascular invasion. These histopathologic factors were all significantly associated with the tested clinical outcomes in a multivariable analysis. Moderate (hazard ratio, 1.190; P < .001) and poor differentiation (hazard ratio, 1.204; P < .001) and lymph-vascular invasion (hazard ratio, 1.465; P < .001) were also associated with significantly poorer overall survival. LIMITATIONS/CONCLUSIONS:Data on disease-specific survival not available in the data set. CONCLUSIONS:We demonstrate the association of the histopathologic characteristics of vSCC with clinically important outcomes. These data may provide individualized information when discussing diagnostic/treatment recommendations, particularly regarding sentinel lymph node biopsy. These data may also guide future staging and risk stratification efforts for vSCC.

BACKGROUND:Lymphocyte activation-gene 3 (LAG-3) is an emerging next-generation immune checkpoint molecule. We aim to define the expression pattern of LAG-3 in cutaneous squamous cell carcinoma (cSCC) as a first step to understand the role of LAG-3 in cSCC prognosis and therapy. OBJECTIVE:To define the expression pattern of LAG-3 in cSCC as a first step to understand the role of LAG-3 in cSCC prognosis and therapy. METHODS:To test whether LAG-3 is expressed on cSCC infiltrating lymphocytes, we isolated CD8 + T lymphocytes from three SCC tumors using flow cytometry and performed single-cell RNA sequencing for LAG-3 and programmed cell death protein -1 (PD-1). In addition, we evaluated LAG-3 mRNA expression in formalin-fixed, paraffin-embedded tissue using NanoString technology. RESULTS:Single-cell RNA sequencing showed that LAG-3 is expressed more than PD-1 in CD8 + tumor infiltrating lymphocytes (50.8% vs 35.2%, respectively). Quantifying LAG-3 mRNA expression showed that compared with normal skin, LAG-3 mRNA is approximately 8 fold higher in immunocompetent associated SCC tumors and approximately 2 fold higher in transplant associated SCC tumors ( p -values <.05). In addition, LAG-3 mRNA was expressed 7.2 fold higher in T2a SCC tumors compared with normal skin ( p -value <.05). CONCLUSION:Lymphocyte activation-gene 3 is expressed on SCC infiltrating T lymphocytes at a higher percentage than PD-1. In addition, LAG-3 mRNA expression is significantly higher in SCC tumors. Ongoing studies will be performed to define its role as an immune-related biomarker and as a therapeutic target.

IMPORTANCE:Merkel cell carcinoma (MCC) is a rare cutaneous malignant neoplasm with increasing incidence and high mortality. Although it is accepted that the optimal treatment for localized tumors is surgical, the data surrounding the optimal surgical approach are mixed, and current National Comprehensive Cancer Network guidelines state that Mohs micrographic surgery (MMS) and wide local excision (WLE) can both be used. The current National Comprehensive Cancer Network guidelines do not advocate a preference for MMS or WLE and suggest that they can be used interchangeably. OBJECTIVE:To evaluate the association of surgical approach with overall survival after excision of localized T1/T2 MCC. DESIGN, SETTING, AND PARTICIPANTS:This retrospective cohort study used the National Cancer Database to assess adults with T1/T2 MCC who were diagnosed between January 1, 2004, and December 31, 2018, with pathologically confirmed, negative regional lymph nodes and treated with surgery. The National Cancer Database includes all reportable cases from Commission on Cancer-accredited facilities. Data analysis was performed from October 2022 to May 2023. EXPOSURE:Surgical approach. MAIN OUTCOMES AND MEASURES:Overall survival. RESULTS:A total of 2313 patients (mean [SD] age, 71 [10.6] years; 1340 [57.9%] male) were included in the study. Excision with MMS had the best unadjusted survival, with mean (SE) survival rates of 87.4% (3.4%) at 3 years, 84.5% (3.9%) at 5 years, and 81.8% (4.6%) at 10 years vs 86.1% (0.9%) at 3 years, 76.9% (1.2%) at 5 years, and 60.9% (2.0%) at 10 years for patients treated with WLE. Patients treated with narrow-margin excision had similar survival as those treated with WLE, with mean (SE) survival rates of 84.8% (1.4%) at 3 years, 78.3% (1.7%) at 5 years, and 60.8% (3.6%) at 10 years. On multivariable survival analysis, excision with MMS was associated with significantly improved survival compared with WLE (hazard ratio, 0.59; 95% CI, 0.36-0.97; P = .04). High-volume MCC centers were significantly more likely to use MMS over WLE compared with other centers (odds ratio, 1.99; 95% CI, 1.63-2.44; P < .001). CONCLUSIONS AND RELEVANCE:In this cohort study, the use of MMS (compared with WLE) was associated with significantly improved survival for patients with localized MCC with pathologically confirmed negative lymph nodes treated with surgery. These data suggest that Mohs surgery may provide a more effective treatment for MCC primary tumors than conventional WLE, although the lack of randomization and potential for selection bias in this study highlight the need for future prospective work evaluating this issue.

Whereas the cellular and molecular features of human inflammatory skin diseases are well characterized, their tissue context and systemic impact remain poorly understood. We thus profiled human psoriasis (PsO) as a prototypic immune-mediated condition with a high predilection for extracutaneous involvement. Spatial transcriptomics (ST) analyses of 25 healthy, active lesion, and clinically uninvolved skin biopsies and integration with public single-cell transcriptomics data revealed marked differences in immune microniches between healthy and inflamed skin. Tissue-scale cartography further identified core disease features across all active lesions, including the emergence of an inflamed suprabasal epidermal state and the presence of B lymphocytes in lesional skin. Both lesional and distal nonlesional samples were stratified by skin disease severity and not by the presence of systemic disease. This segregation was driven by macrophage-, fibroblast-, and lymphatic-enriched spatial regions with gene signatures associated with metabolic dysfunction. Together, these findings suggest that mild and severe forms of PsO have distinct molecular features and that severe PsO may profoundly alter the cellular and metabolic composition of distal unaffected skin sites. In addition, our study provides a valuable resource for the research community to study spatial gene organization of healthy and inflamed human skin.

BACKGROUND:Vulvar melanoma is a rare malignancy with frequent recurrence and poor prognosis. National guidelines recommend wide local excision of these tumors with allowances for narrower margins for anatomic and functional limitations, which are common on specialty sites. There is presently a lack of data of margin positivity after standard excision of vulvar melanomas. OBJECTIVE:We aim to evaluate the rate of positive margins after standard excision of vulvar melanomas. MATERIALS AND METHODS/METHODS:Retrospective cohort study of surgically excised vulvar melanomas from the NCDB diagnosed from 2004 to 2019. RESULTS:We identified a total of 2,226 cases. Across surgical approaches and tumor stages, 17.2% (Standard Error [SE]: 0.8%) of cases had positive surgical margins. Among tumor stages, T4 tumors were most commonly excised with positive margins (22.9%, SE: 1.5%). On multivariable survival analysis, excision with positive margins was associated with significantly poorer survival (Hazard Ratio 1.299, p = .015). CONCLUSION/CONCLUSIONS:We find that positive margin rates after standard excision of vulvar malignancies are higher than for other specialty site melanomas. Our data suggest that use of surgical approaches with complete margin assessment may improve local control and functional outcomes for patients with vulvar melanoma as they have for patients with other specialty site melanomas.

LINE-1 retrotransposons are sequences capable of copying themselves to new genomic loci via an RNA intermediate. New studies implicate LINE-1 in a range of diseases, especially in the context of aging, but without an accurate understanding of where and when LINE-1 is expressed, a full accounting of its role in health and disease is not possible. We therefore developed a method-5' scL1seq-that makes use of a widely available library preparation method (10x Genomics 5' single cell RNA-seq) to measure LINE-1 expression in tens of thousands of single cells. We recapitulated the known pattern of LINE-1 expression in tumors-present in cancer cells, absent from immune cells-and identified hitherto undescribed LINE-1 expression in human epithelial cells and mouse hippocampal neurons. In both cases, we saw a modest increase with age, supporting recent research connecting LINE-1 to age related diseases.