Faculty Bibliography

Primary cutaneous squamous cell carcinoma (cSCC) is the second most common human cancer with a rising incidence of about 1.8 million in the United States annually. Primary cSCC is usually curable by surgery; however, in some cases, cSCC eventuates in nodal metastasis and death from disease specific death. cSCC results in up to 15,000 deaths each year in the United States. Until recently, non-surgical options for treatment of locally advanced or metastatic cSCC were largely ineffective. With the advent of checkpoint inhibitor immunotherapy, including cemiplimab and pembrolizumab, response rates climbed to 50%, representing a vast improvement over chemotherapeutic agents used previously. Herein, we discuss the phenotype and function of SCC associated Langerhans cells, dendritic cells, macrophages, myeloid derived suppressor cells and T cells as well as SCC-associated lymphatics and blood vessels. Possible role(s) of SCC-associated cytokines in progression and invasion are reviewed. We also discuss the SCC immune microenvironment in the context of currently available and pipeline therapeutics.

IMPORTANCE/UNASSIGNED:Primary cutaneous squamous cell carcinoma is usually curable; however, a subset of patients develops poor outcomes, including local recurrence, nodal metastasis, distant metastasis, and disease-specific death. OBJECTIVES/UNASSIGNED:To evaluate all evidence-based reports of patient risk factors and tumor characteristics associated with poor outcomes in primary cutaneous squamous cell carcinoma and to identify treatment modalities that minimize poor outcomes. DATA SOURCES/UNASSIGNED:PubMed, Embase, and SCOPUS databases were searched for studies of the topic in humans, published in the English language, from database inception through February 8, 2022. STUDY SELECTION/UNASSIGNED:Two authors independently screened the identified articles and included those that were original research with a sample size of 10 patients or more and that assessed risk factors and/or treatment modalities associated with poor outcomes among patients with primary cutaneous squamous cell carcinoma. DATA EXTRACTION AND SYNTHESIS/UNASSIGNED:Data extraction was performed by a single author, per international guidelines. The search terms, study objectives, and protocol methods were defined before study initiation. A total of 310 studies were included for full-text assessment. Owing to heterogeneity of the included studies, a random-effects model was used. Data analyses were performed from May 25 to September 15, 2022. MAIN OUTCOMES AND MEASURES/UNASSIGNED:For studies of risk factors, risk ratios and incidence proportions; and for treatment studies, incidence proportions. RESULTS/UNASSIGNED:In all, 129 studies and a total of 137 449 patients with primary cutaneous squamous cell carcinoma and 126 553 tumors were included in the meta-analysis. Several patient risk factors and tumor characteristics were associated with local recurrence, nodal metastasis, distant metastasis, disease-specific death, and all-cause death were identified. Among all factors reported by more than 1 study, the highest risks for local recurrence and disease-specific death were associated with tumor invasion beyond subcutaneous fat (risk ratio, 9.1 [95% CI, 2.8-29.2] and 10.4 [95% CI, 3.0- 36.3], respectively), and the highest risk of any metastasis was associated with perineural invasion (risk ratio, 5.0; 95% CI, 2.3-11.1). Patients who received Mohs micrographic surgery had the lowest incidence of nearly all poor outcomes; however, in some results, the 95% CIs overlapped with those of other treatment modalities. CONCLUSIONS AND RELEVANCE/UNASSIGNED:This meta-analysis identified the prognostic value of several risk factors and the effectiveness of the available treatment modalities. These findings carry important implications for the prognostication, workup, treatment, and follow-up of patients with primary cutaneous squamous cell carcinoma. TRIAL REGISTRATION/UNASSIGNED:PROSPERO Identifier: CRD42022311250.

There is controversy regarding the optimal surgical modality and ideal recommended margins for treating melanoma in situ (MIS) and invasive melanoma (IM). Although wide local excision is recommended, staged excision offers excellent margin control and low recurrence rates. In this manuscript, we reviewed a 10-year experience of staged excisions for the treatment of MIS and IM. A retrospective review was performed of 130 MIS and 32 IM cases treated with staged excision from April 2012 to April 2022. Staged excision was performed on the head and neck in 102 (79%) MIS and 23 (72%) IM cases. Approximately 10% of cases required surgical margins above the current recommendations (11 (9%) MIS and 6 (19%) IM). Twenty-three (19%) MIS and 7 (22%) IM cases required more than one excision to obtain clearance. Recurrence rates among MIS and IM were 0.0% and 0.6%, respectively. Upstaging occurred in 5 (4%) MIS and 7 (22%) IM cases. Complex repairs were performed on 82 (63%) MIS and 17 (53%) IM cases. Our findings revealed that staged excision provides effective margin control and low recurrence rates. Approximately 10% of patients required margins greater than the current recommendations, leading to larger defects and more complex repairs.

It is well established that immunosuppressed patients are at increased risk for poor outcomes (PO) from cutaneous squamous cell carcinoma (cSCC), including local recurrence (LR), nodal metastasis (NM), distant metastasis (DM), and disease-specific death (DSD). Defining PO risk is challenging but may be beneficial in guiding management. We aimed to define PO risk factors and evaluated their importance in immunosuppressed versus immunocompetent patients. We conducted a 4-year single-center retrospective review of patients with cSCC. Patient and tumor characteristics were evaluated in those that experienced PO. Immunosuppressed patients were ~ 11-fold more likely than immunocompetent patients to develop PO (10/85 vs. 15/1332, p < 0.0001). Among those with PO, immunosuppressed patients had diminished relapse free (p = 0.026) and progression free (p < 0.001) survival compared to immunocompetent. Immunosuppression was significantly associated with LR (p < 0.00001). Immunosuppressed patients were also more likely to develop NM, DM and experience DSD (p = 0.027). Mohs Appropriate Use Criteria was associated with NM, DM and DSD (p = 0.029), with area H tumors more likely to result in metastasis and death. In conclusion, immunosuppressed patients are more likely to develop LR, metastasis, and DSD from cSCC compared to immunocompetent patients. Immunosuppressed status was an independent risk factor for PO in this cohort and further considered for its inclusion in prognostication schema is warranted.

INTRODUCTION/BACKGROUND:Nasal reconstruction has important functional and cosmetic considerations, as proper repair of nasal defects is necessary to maintain function of the nasal airway and to recreate the normal appearance of this central facial structure. Cheek advancement flaps provide matched, mobile and highly vascularized tissue for the reconstruction of nasal defects, allowing for the concealment of incisions within natural creases in a one-stage approach. However, cheek advancement flaps are often underutilized for nasal reconstruction because of their difficulty restoring nasal contour. METHODS:We describe reconstruction of 19 nasal dorsal and sidewall defects 0.8 to 3.0 centimeters (cm) in size. We incorporated a periosteal anchoring suture to maintain/restore nasal contour and additionally removed a half standing cone inferior to the defect to prevent encroachment of the nasal ala or alar crease. All patients were evaluated at least 3 months post-operatively. RESULTS:In all patients, we were able to restore concavity of the nasofacial sulcus, preserve the biconvex nasal tips, prevent alar flaring and retraction and conserve the alar groove. All patients had excellent functional and cosmetic outcomes. CONCLUSION/CONCLUSIONS:We believe this modified cheek advancement flap provides functionally and aesthetically superior results and can be considered as a first-line approach for repair of nasal dorsal and sidewall defects in sub selected patients.

Background/Purpose: The skin is recognized as a window into the immunopathogenic mechanisms driving the vast phenotypic spectrum of psoriatic disease.
Method(s): To better decipher the cellular landscape of both healthy and psoriatic skin, we employed spatial transcriptomics (ST), a ground-breaking technology that precisely maps gene expression from histologically-intact tissue sections (Fig. 1A).
Result(s): Findings gleaned from computationally integrating our 23 matched lesional and non-lesional psoriatic and 7 healthy control samples with publicly-available single-cell ribonucleic acid (RNA) sequencing datasets established the ability of ST to recapitulate the tissue architecture of both healthy and inflamed skin (Fig. 1B) and highlighted topographic shifts in the immune cell milieu, from a predominantly perifollicular distribution in steady-state skin to the papillary and upper reticular dermis in psoriatic lesional skin. We also incidentally discovered that ST's ability to ascertain gene expression patterns from intact tissue rendered it particularly conducive to studying the transcriptome of lipid-laden cells such as dermal adipose tissue and sebaceous glands (Fig. 1C), whose expression profiles are typically lost in the process of tissue handling and dissociation for bulk and single-cell RNA seq. Unbiased clustering of pooled healthy and psoriatic samples identified two epidermal clusters and one dermal cluster that were differentially expanded in psoriatic lesional skin (p values <=0.05) (Fig. 1D); pathway analysis of these clusters revealed enrichment of known psoriatic inflammatory pathways (Fig. 1E). Unsupervised classification of skin-limited psoriasis and psoriatic arthritis samples revealed stratification by cutaneous disease severity or Psoriasis Area and Severity Index (PASI) score and not by presence or absence of concomitant systemic/synovial disease (Fig. 1F). Remarkably, this PASI-dependent segregation was also evident in distal, non-lesional samples and was driven by the dermal macrophage and fibroblast cluster and the lymphatic endothelium (Fig. 2A). Inquiry into the mechanistic drivers of this observed stratification yielded enrichment of pathways associated with key T cell and innate immune cell activation, B cells, and metabolic dysfunction (Fig. 2B). Finally, tissue scale computational cartography of gene expression revealed differences in regional enrichment of specific cell types across phenotypic groups, most notably upward extension of fibroblasts to the upper dermis in both lesional and non-lesional samples from mild psoriasis and restriction to the lower dermis in the moderate-to-severe psoriasis samples (Fig. 2C), suggesting that disease severity stratification may be driven by emergent cellular ecosystems in the upper dermis. Fig. 1. (A) Schematic of spatial transcriptomics study workflow. Four mm skin punch biopsies were obtained from healthy volunteers (n=3) and lesional and non-lesional skin from patients with psoriatic disease (n=11). Ten micron-thick sections were then placed on capture areas on the ST microarray slide, each containing molecularly barcoded, spatially encoded spots with a diameter of 50 microns and a center-to-center distance of 100 microns. (B) Side-by-side comparison of a hematoxylin-eosin (H&E) stained section of representative healthy, lesional, and non-lesional skin samples and the corresponding ST plots showed concordance of unbiased gene expression-based clustering with histologic tissue architecture. (C) Pathway analysis of the adipose cluster in healthy skin (cluster 2) confirmed upregulation of lipid-associated processes. Inset: Spots corresponding to the adipose cluster highlighted in yellow. (D) Wilcoxon rank sum test (results displayed as box plots) yielded statistically significant expansion of three clusters in lesional skin compared to both non-lesional and healthy skin-inflamed suprabasal epidermis (cluster 4), epidermis 2 (cluster 7), and inflamed dermis (cluster 10). HC=healthy control, L=lesional psoriatic skin, NL=non-lesional psoriatic skin. (E) Pathways enriched in clusters 4, 7, and 10. (F) Principal component analysis (PCA) plots demonstrating segregation of samples by severity of cutaneous disease in both lesional and non-lesional samples along the first principal component (right) that was not seen in the samples categorized according to presence or absence of arthritis (left). PsA=psoriatic arthritis, PsO=skin-limited psoriasis. Fig. 2. (A) PCA of lesional and non-lesional samples colored by disease severity in spatial clusters 1 (left) and 12 (right) revealed more discrete clustering. (B) Pathways significantly enriched in clusters 1 (left) and 12 (right) showed enrichment of pathways associated with key T cell and innate immune cell activation, B cells, and metabolic dysfunction (highlighted in red). (C) SpaceFold one dimension projection of cell distribution from an independently-generated single-cell RNA seq data set on aggregated ST lesional and non-lesional samples from mild (PASI-low) and moderate-severe (PASI-high) samples. Y-axis represents tissue position, starting with the lower dermis marked as position 0 to suprabasal epidermis marked as position 1. Dashed line represents epidermal-dermal junction, discerned by cell types in the basal epidermal layer (melanocytes and Langerhans cells). Fibroblast signatures (red arrows) were largely relegated to the lower dermis in the PASI-high group, but extended to the upper dermis in the PASI-low group. This striking difference in fibroblast localization was also noted in non-lesional PASI-high vs. PASI-low groups. In addition to fibroblasts, lymphatic, endothelial, myeloid, and T cells signatures (black arrows) were also observed in the upper dermis of lesional PASI-low samples, but were much lower in the dermis of PASI-low non-lesional and all samples in the PASI-high group. Interfollicular epidermis (IFE), hair follicle and infundibulum (HF/IFN), n= number of individual biopsies.
Conclusion(s): Thus, we have been able to successfully leverage ST integrated with independently-generated single-cell RNA seq data to spatially define the emergent cellular ecosystems of healthy and matched psoriatic lesional and non-lesional skin and in so doing, demonstrated the value of ST in unearthing the genetic groundwork at both the site of inflammation and in distal, clinically-uninvolved skin