Invasive Squamous Cell Carcinoma of the Skin: Defining a High-Risk Group

Distinguishing of Histopathological Staging Features of H-E Stained Human cSCC by Microscopical Multispectral Imaging

Cutaneous squamous cell carcinoma (cSCC) is the second most common malignant skin tumor. Early and precise diagnosis of tumor staging is crucial for long-term outcomes. While pathological diagnosis has traditionally served as the gold standard, the assessment of differentiation levels heavily depends on subjective judgments. Therefore, how to improve the diagnosis accuracy and objectivity of pathologists has become an urgent problem to be solved. We used multispectral imaging (MSI) to enhance tumor classification. The hematoxylin and eosin (H&E) stained cSCC slides were from Shanghai Ruijin Hospital. Scale-invariant feature transform was applied to multispectral images for image stitching, while the adaptive threshold segmentation method and random forest segmentation method were used for image segmentation, respectively. Synthetic pseudo-color images effectively highlight tissue differences. Quantitative analysis confirms significant variation in the nuclear area between normal and cSCC tissues (p < 0.001), supported by an AUC of 1 in ROC analysis. The AUC within cSCC tissues is 0.57. Further study shows higher nuclear atypia in poorly differentiated cSCC tissues compared to well-differentiated cSCC (p < 0.001), also with an AUC of 1. Lastly, well differentiated cSCC tissues show more and larger keratin pearls. These results have shown that combined MSI with imaging processing techniques will improve H&E stained human cSCC diagnosis accuracy, and it will be well utilized to distinguish histopathological staging features.

Competing-risks analysis for evaluating the prognosis of patients with microinvasive cutaneous squamous cell carcinoma based on the SEER database

BACKGROUND

Utilizing the traditional Cox regression model to identify the factors affecting the risk of mortality due to microinvasive cutaneous squamous cell carcinoma (micSCC) may produce skewed results. Since cause-specific mortality can guide clinical decision-making, this study employed the Fine-Gray model based on the Surveillance, Epidemiology, and End Results (SEER) database to identify significant predictive variables for the risk of micSCC-related mortality.

METHODS

This study used the information of patients with micSCC who were listed in the SEER database during 2000-2015. Cox regression and Fine-Gray models were utilized for the multivariable analysis, and Gray's test and the cumulative incidence function were used for the univariable analyses.

RESULTS

There were 100 patients who died from other reasons and 38 who died from micSCC among the 1259 qualified patients with micSCC. Most were female, white, married, had localized metastasis, etc. According to the univariable Gray's test (P < 0.05), the cumulative incidence rate for events of interest was strongly associated with age, sex, marital status, American Joint Committee on Cancer staging, radiation status, summary stage, chemotherapy status, surgery status, and tumor size. Multivariable Cox regression analysis and multivariable competing-risks analysis indicated that age, tumor size, and income were independent risk variables for the prognosis of patients with micSCC. In both age and tumor size variables, the competing-risks model showed a slight decrease in the hazard ratio and a slight narrowing of the 95% confidence interval compared with the Cox regression model. However, this pattern is not evident in the income variable.

CONCLUSIONS

This study established a Fine-Gray model for identifying the independent risk factors that influence the risk of mortality among patients with micSCC. This study uncovers that, in the context of competing risks, age, tumor size, and income serve as independent risk factors influencing the risk of mortality due to micSCC among patients. Our findings have the potential to provide more accurate risk assessments for patient outcomes and contribute to the development of individualized treatment plans.

Defining and quantifying histopathologic risk factors for regional and distant metastases in a large cohort of vulvar squamous cell carcinomas

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

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.

Validation of the 2022 National Comprehensive Cancer Network Risk Stratification for Cutaneous Squamous Cell Carcinoma

Importance

The 2022 National Comprehensive Cancer Network (NCCN) reclassified cutaneous squamous cell carcinoma (CSCC) into low-, high-, and very high-risk groups to better risk stratify tumors. Mohs micrographic surgery (Mohs) or peripheral and deep en face margin assessment (PDEMA) became preferred surgical modalities for high- and very high-risk tumors. This new risk stratification and the recommendation for Mohs or PDEMA in high- and very high-risk groups have not been validated.

Objective

To compare outcomes in very high-, high-, and low-risk NCCN groups of CSCCs and in CSCCs treated with Mohs or PDEMA compared with wide local excision (WLE).

Design, Setting, and Participants

This retrospective cohort study of CSCCs was performed in 2 tertiary care academic medical centers. Patients 18 years or older and diagnosed between January 1, 1996, and December 31, 2019, at Brigham and Women's Hospital and Cleveland Clinic Foundation were included. Data were analyzed from October 20, 2021, to March 29, 2023.

Exposures

NCCN risk group, Mohs or PDEMA, and WLE.

Main Outcomes and Measures

Local recurrence (LR), nodal metastasis (NM), distant metastasis (DM), and disease-specific death (DSD).

Results

A total of 10 196 tumors from 8727 patients were stratified by NCCN guidelines into low-, high-, and very high-risk groups (6003 [59.0%] men; mean [SD] age, 72.4 [11.8] years). Compared with the low-risk group, the high- and very high-risk groups demonstrated a greater risk of LR (high-risk subhazard ratio [SHR], 1.99 [95% CI, 1.21-3.27; P = .007]; very high-risk SHR, 12.66 [95% CI, 7.86-20.39; P < .001]), NM (high-risk SHR, 4.26 [95% CI, 1.28-14.23; P = .02]; very high-risk SHR, 62.98 [95% CI, 19.24-206.17; P < .001]), DM (high-risk SHR, 2.2 × 107 [95% CI, 4.7 × 103-1.1 × 1011; P < .001]; very high-risk SHR, 6.3 × 108 [95% CI, 1.4 × 105-2.9 × 1012; P < .001]), and DSD (high-risk SHR, 4.02 [95% CI, 1.18-13.71; P = .03]; very high-risk SHR, 93.87 [95% CI, 29.19-301.85; P < .001]). Adjusted 5-year cumulative incidence was significantly higher in very high- vs high- and low-risk groups for LR (9.4% [95% CI, 9.2%-14.0%] vs 1.5% [95% CI, 1.4%-2.1%] and 0.8% [95% CI, 0.5%-1.2%], respectively), NM (7.3% [95% CI, 6.8%-10.9%] vs 0.5% [95% CI, 0.4%-0.8%] and 0.1% [95% CI, 0.03%-0.3%], respectively), DM (3.9% [95% CI, 2.6%-5.6%] vs 0.1% [95% CI, 0.04%-0.2%] and 0.01% [95% CI, not applicable], respectively), and DSD (10.5% [95% CI, 10.3%-15.4%] vs 0.5% [95% CI, 0.4%-0.8%] and 0.1% [95% CI, 0.04%-0.3%], respectively). Compared with CSCCs treated with WLE, those treated with Mohs or PDEMA had lower risk of LR (SHR, 0.65 [95% CI, 0.46-0.90]; P = .009), DM (SHR, 0.38 [95% CI, 0.18-0.83]; P = .02), and DSD (SHR, 0.55 [95% CI, 0.36-0.84]; P = .006).

Conclusions and Relevance

The findings of this cohort study suggest that the NCCN high- and very high-risk groups identify CSCCs at greatest risk for developing poor outcomes. Further, Mohs or PDEMA resulted in lower LR, DM, and DSD compared with WLE.

Role of Sentinel Lymph Node Biopsy for Skin Cancer Based on Clinical Studies

The sentinel lymph node is the first lymph node from the primary tumor. Sentinel lymph node biopsy (SLNB) is a surgical procedure that can detect occult nodal metastasis with relatively low morbidity. It may also have a therapeutic effect via regional disease control. The Multicenter Selective Lymphadenectomy-I (MSLT-I) trial revealed a prognostic benefit from SLNB in melanoma patients. However, it remains unclear whether there is a prognostic benefit from SLNB in patients with nonmelanoma skin cancer owing to a lack of randomized prospective studies. Nevertheless, SLNB provides important information about nodal status, which is one of the strongest factors to predict prognosis and may guide additional nodal treatment. Currently, SLNB is widely used in the management of not only patients with melanoma but also those with nonmelanoma skin cancer. However, the utilization and outcomes of SLNB differ among skin cancers. In addition, SLNB is not recommended for routine use in all patients with skin cancer. In this review, we provide a summary of the role of SLNB and of the indications for SLNB in each skin cancer based on previously published articles.

Association of Patient Risk Factors, Tumor Characteristics, and Treatment Modality With Poor Outcomes in Primary Cutaneous Squamous Cell Carcinoma: A Systematic Review and Meta-analysis

Importance

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

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

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

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

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

For studies of risk factors, risk ratios and incidence proportions; and for treatment studies, incidence proportions.

Results

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

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

PROSPERO Identifier: CRD42022311250.

Predictors of Nodal Metastasis in Cutaneous Head and Neck Cancers

PURPOSE OF REVIEW

The complex and varied drainage patterns in the head and neck present a challenge in the regional control of cutaneous neoplasms. Lymph node involvement significantly diminishes survival, often warranting more aggressive treatment. Here, we review the risk factors associated with lymphatic metastasis, in the context of the evolving role of sentinel lymph node biopsy.

RECENT FINDINGS

In cutaneous head and neck melanomas, tumor thickness, age, size, mitosis, ulceration, and specific histology have been associated with lymph node metastasis (LNM). In head and neck cutaneous squamous cell carcinomas, tumor thickness, size, perineural invasion, and immunosuppression are all risk factors for nodal metastasis. The risk factors for lymph node involvement in Merkel cell carcinoma are not yet fully defined, but emerging evidence indicates that tumor thickness and size may be  associated with regional metastasis. The specific factors that predict a greater risk of LNM for cutaneous head and neck cancers generally include depth of invasion, tumor size, mitotic rate, ulceration, immunosuppression, and other histopathological factors.

Recurrence Status, Perineural Invasion, and Hypothyroidism Are Associated With Lymph Node Metastasis in Cutaneous Squamous Cell Carcinoma: A Case-Control Study

BACKGROUND

Lymph node metastasis is a critical prognostic indicator for mortality in patients with cutaneous squamous cell carcinoma (SCC).

OBJECTIVE

To identify and characterize key risk factors for SCC lymph node metastasis.

METHODS

This was a multi-institutional, case-control study of 65 cutaneous SCCs with known lymph node metastasis matched with 195 cutaneous SCCs without lymph node metastasis (3:1 matching). The cases and controls were matched by anatomic location, age, and sex. Odds ratios (ORs) and their 95% confidence intervals (CIs) were generated to determine the association between specific risk factors and lymph node metastasis in a multivariate analysis.

RESULTS

Recurrent tumors (p < .001), perineural invasion (p < .001), lymphovascular invasion (p = .002), size of 2 cm or greater (p = .008), and hypothyroidism (p = .03) were significantly more common in the lymph node metastasis cohort. Recurrence (OR 6.3, 95% CI 2.6-15.3), perineural invasion (OR 4.5, 95% CI 1.7-11.8), and hypothyroidism (OR 2.7, 95% CI 1.04-7.0) remained significant on performing a multivariate analysis.

CONCLUSION

Lymph node metastasis in SCC is associated with recurrence, perineural invasion, lymphovascular invasion, size of 2 cm or greater, and hypothyroidism. Clinical consideration of these findings within the context of current staging systems may help improve patient outcomes.

Implications of Satellitosis or In-transit Metastasis in Cutaneous Squamous Cell Carcinoma: A Prognostic Omission in Cancer Staging Systems

IMPORTANCE

Unlike Merkel cell carcinoma and melanoma, satellitosis or in-transit metastasis (S-ITM) is not incorporated into the current cutaneous squamous cell carcinoma (CSCC) staging systems. It is important to determine if the clinical outcomes of S-ITM are relevant to prognosis for patients with CSCC.

OBJECTIVES

To evaluate the association of S-ITM with clinical outcomes in patients with CSCC and to determine its prognostic implications.

DESIGN, SETTINGS, AND PARTICIPANTS

A dual-institution (Cleveland Clinic and Brigham and Women's Hospital) database was queried for patients who were treated for CSCC in 2010 to 2020. Patients who were node-negative and had S-ITM-the presence of dermal lesions between the primary tumor and first-echelon lymphatic nodal basins at any point in the disease course-were identified. Subcohorts of patients with T3N0 tumors, T4N0 tumors (bone invasive), N1 to 3, and M1 disease were identified for comparison. The American Joint Committee on Cancer staging system was used to define cancer stages. Data were analyzed from January 15 to March 31, 2021.

MAIN OUTCOMES AND MEASURES

Pairwise comparison of CSCC recurrence and disease-specific survival in patients with and without S-ITM was performed using Cox proportional hazard modeling. Kaplan-Meier and Fine-Gray competing risk methods were used to estimate disease-specific survival and CSCC recurrence, respectively.

RESULTS

In a total of 518 patients with CSCC, S-ITM was present in 72 (13.9 %) patients (median age [range], 73.9 [31.6-95.8] years; 59 [82%] men; 69 [96%] White non-Hispanic individuals; 25 [35%] patients with immunosuppression) who were node-negative. The subcohorts were composed of 341 patients with T3N0 cancer, 36 with T4N0, 70 with N1 to 3, and 19 with M1 disease. Pairwise comparisons between disease levels using Cox proportional hazard model demonstrated lower cumulative incidence of CSCC recurrence rates in the T3N0 (HR, 0.21; 95% CI, 0.14-0.30; P < .001) and T4N0 (HR, 0.36; 95% CI, 0.19-0.68; P = .001) cohorts compared with the S-ITM cohort. No significant difference was observed between patients who were node-positive and those with S-ITM (HR, 0.74; 95% CI, 0.48-1.14; P = .16). The 5-year disease-specific survival rates were 76% for T3N0, 64% for T4N0, 41% for S-ITM, and 39% for N1 to 3. Compared with the S-ITM cohort, DSS was significantly higher in the T3N0 (HR, 0.23; 95% CI, 0.15-0.35; P < .0001) and T4N0 (HR, 0.37; 95% CI, 0.19-0.76; P = .01) cohorts, and not significantly different in the node-positive (HR, 0.77; 95% CI, 0.84-3.93; P = .30) and metastatic cohorts (HR, 1.81; 95% CI, 0.84-3.93; P = .13).

CONCLUSIONS AND RELEVANCE

This multi-institutional cohort study found that patients with CSCC and S-ITM appear to have clinical outcomes comparable to those of patients who are node-positive, and an increased risk of recurrence and worse survival compared with patients who have T3 and T4 disease. These outcomes are similar to those observed for Merkel cell carcinoma and melanoma. Given that S-ITM may be a powerful prognostic factor, it should be incorporated into clinical staging systems.

Adjuvant radiotherapy may not significantly change outcomes in high-risk cutaneous squamous cell carcinomas with clear surgical margins: A systematic review and meta-analysis

BACKGROUND

The role of adjuvant radiotherapy for high-risk cutaneous squamous cell carcinomas (cSCC) after surgery with negative margins is unclear.

OBJECTIVE

To conduct a systematic review and meta-analysis examining the risk of poor outcomes for those treated with surgery vs. surgery and adjuvant radiotherapy.

METHODS

A comprehensive search of articles was executed in PubMed, Embase, and Cochrane Database. Random-effected meta-analyses were conducted.

RESULTS

Thirty-three studies comprised of 3,867 high-risk cSCC were included. There were no statistically significant differences in poor outcomes between the surgery vs. surgery and adjuvant radiotherapy groups. Estimates for local recurrence were 15.2% (95% confidence interval [CI]: 6.3%-27%) vs. 8.8% (CI: 1.6%-20.9%), regional metastases were 11.5% (CI: 7.2%-16.7%) vs. 4.4% (CI: 0%-18%), distant metastases were 2.6% (CI: 0.6%-6%) vs. 1.7% (CI: 0.2%-4.5%) and disease-specific deaths were 8.2% (CI: 1.2%-20.6%) vs. 19.7% (CI: 3.8%-43.7%) for the surgery group vs. surgery and adjuvant radiotherapy group respectively.

LIMITATIONS

Retrospective nature of most studies with a lack of sufficient patient-specific data.

CONCLUSIONS

For patients with high risk cSCC treated with margin-negative resection, there were no differences in poor outcomes between the surgery vs. surgery and adjuvant radiotherapy groups. Randomized-controlled trials are necessary to define the benefit of adjuvant radiotherapy in this setting.

Higher metastasis and death rates in cutaneous squamous cell carcinomas with lymphovascular invasion

BACKGROUND

Lymphovascular invasion (LVI) is an aggressive histologic finding but is excluded from current staging systems due to its lack of demonstrated independent prognostic significance.

OBJECTIVE

To evaluate the impact of LVI on cutaneous squamous cell carcinoma tumor outcomes.

METHODS

In total, 10,707 cutaneous squamous cell carcinoma tumors from a 20-year, retrospective, multicenter cohort were stratified by the presence (LVI⁺) or absence (LVI^-) of LVI. Outcomes (local recurrence, in-transit metastasis, nodal metastasis, disease-specific death) were compared based on low (Brigham and Women's Hospital [BWH] stage T1/T2a) and high (BWH T2b/T3) tumor stages.

RESULTS

Of the 10,707 tumors, 78 had LVI. The analysis of low-stage BWH tumors showed the LVI⁺ group had a significantly higher 5-year cumulative incidence of local recurrence (LVI⁺: 12.3%; LVI^-: 1.1%; P < .01), metastasis (LVI⁺: 4.2%; LVI^-: 0.4%; P < .01), and disease-specific death (LVI⁺: 16.2%; LVI^-: 0.4%; P < .01). The analysis of BWH high-stage tumors showed the LVI⁺ group maintained a higher 5-year cumulative incidence of metastasis (LVI⁺: 28.5%; LVI^-: 16.8%; P = .06) and disease-specific death (LVI⁺: 25.3%; LVI^-: 13.9%; P = .03), however, there was no difference in local recurrence (LVI⁺: 16.3%; LVI^-: 15.8%; P = .11).

LIMITATIONS

Retrospective study design.

CONCLUSION

LVI⁺ cutaneous squamous cell carcinomas have higher rates of metastasis and death at 5 years. Future staging systems should consider incorporating LVI.

The immunoexpression of epidermal growth factor receptor in cutaneous squamous cell carcinoma

Although cutaneous squamous cell carcinomas (cSCCs) account for only 20–25% of non-melanoma skin cancers (NMSCs), they are responsible for most deaths attributable to NMSCs. Apart from SCC seric level, which increases in late-stage disease, no other predictive biomarker for cSCC exists. Epidermal growth factor receptor (EGFR) serves as a predictive biomarker and therapeutic target in numerous malignancies. EGFR immunoexpression is highly elevated in head and neck mucosal SCC. However, its immunoexpression pattern, its relationship with prognosis and survival, and the effect of EGFR targeted therapy in advanced cSCC have not been clarified. We assessed EGFR immunoexpression in 18 cases of cSCC and correlated our findings with the clinicopathological features. Immunohistochemical stainings with anti-EGFR monoclonal antibodies were practiced and the membrane and cytoplasmic immunostaining intensity and quality in the tumors and the non-lesional epithelium were analyzed. Membrane EGFR immunoexpression within the tumors increased with the tumor grade. EGFR overexpression was more frequently found in head and neck cSCCs. We did not find a direct relationship between cytoplasmic EGFR immunoexpression and clinicopathological findings and prognosis. Our results confirm that increased EGFR immunoexpression correlates with aggressive cSCC phenotypes and underline the need for novel treatments for these patients.

Cutaneous Malignancies of the Head and Neck

Cutaneous malignancies (CMs), or skin cancers, are the most common cancer worldwide, with a quarter million cases diagnosed annually in the United States alone. The best described risk factor for CM is ultraviolet radiation from sunlight, and therefore most of these cancers develop in sun-exposed skin, including the head and neck. Beginning with melanoma, immunotherapy has increasingly been used over the past decade for treatment of unresectable CM, and immune checkpoint inhibitors are now Food and Drug Administration-approved for first-line treatment of unresectable melanoma, Merkel cell carcinoma, and cutaneous squamous cell carcinoma, and second-line for basal cell carcinoma.

A Computational Systems Analyses to Identify Biomarkers and Mechanistic Link in Psoriasis and Cutaneous Squamous Cell Carcinoma

Psoriasis is the most common and chronic skin disease that affects individuals from every age group. The rate of psoriasis is increasing over the time in both developed and developing countries. Studies have revealed the possibility of association of psoriasis with skin cancers, particularly non-melanoma skin cancers (NMSC), which, include basal cell carcinoma and cutaneous squamous cell carcinoma (cSCC). There is a need to analyze the disease at molecular level to propose potential biomarkers and therapeutic targets in comparison to cSCC. Therefore, the second analyzed disease of this study is cSCC. It is the second most common prevalent skin cancer all over the world with the potential to metastasize and recur. There is an urge to validate the proposed biomarkers and discover new potential biomarkers as well. In order to achieve the goals and objectives of the study, microarray and RNA-sequencing data analyses were performed followed by network analysis. Afterwards, quantitative systems biology was implemented to analyze the results at a holistic level. The aim was to predict the molecular patterns that can lead psoriasis to cancer. The current study proposed potential biomarkers and therapeutic targets for psoriasis and cSCC. IL-17 signaling pathway is also identified as significant pathway in both diseases. Moreover, the current study proposed that autoimmune pathology, neutrophil recruitment, and immunity to extracellular pathogens are sensitive towards MAPKs (MAPK13 and MAPK14) and genes for AP-1 (FOSL1 and FOS). Therefore, these genes should be further studied in gene knock down based studies as they may play significant role in leading psoriasis towards cancer.

A Rare Case of Invasive Keratinizing Squamous Cell Carcinoma of the Foot

Lower extremity soft-tissue lesions are frequently encountered in clinical practice. Cellulitis, osteomyelitis, and diabetic foot ulcerations remain the top differentials. The acuity of illness, imaging studies, and deep wound cultures are helpful in most cases. Malignancies are rare but need immediate attention. Hereby, we report a case of a chronic heel wound which on workup was confirmed as cutaneous squamous cell carcinoma (SCC).

Risk Factors Party Together: The Role of Perineural Invasion and Desmoplasia in Cutaneous Squamous Cell Carcinoma Prognosis

In the current issue, Haug et al. 2020 report on the prognostic impact of perineural invasion (PNI) and desmoplasia on cutaneous squamous cell carcinoma (CSCC) recurrence and metastasis. They find that PNI occurs exclusively in desmoplastic CSCC, and desmoplasia is independently associated with CSCC recurrence and metastasis after adjusting for well-established CSCC risk factors. Future studies should assess the contribution of desmoplasia in CSCC prognosis.

Outcomes of patients with metastatic cutaneous squamous cell carcinoma to the axilla: a multicentre cohort study

BACKGROUND

Metastatic cutaneous squamous cell carcinoma to the axilla is uncommon, with limited data to guide management. We sought to assess the outcomes of patients with this condition after surgery and radiotherapy.

METHODS

A retrospective cohort study of patients treated at two Australian hospitals from 1994 through 2016 was performed.

RESULTS

A total of 74 patients were identified, including 48 treated curatively with surgery-plus-radiotherapy and 15 with surgery alone. Compared with patients treated with surgery alone, a higher proportion of patients treated with surgery-plus-radiotherapy had lymph nodes larger than 6 cm (53% versus 8%, P = 0.012) and multiple adverse histopathological features (75% versus 47%, P = 0.04). The groups had similar 5-year disease-free survival (45% versus 46%) and overall survival (51% versus 48%). Presence of multiple positive lymph nodes was associated with reduced disease-free survival (hazard ratio 4.57, P = 0.01) and overall survival (hazard ratio 3.53, P = 0.02). Regional recurrence was higher in patients treated with surgery alone (38% versus 22%, P = 0.22) and patients with lymph nodes larger than 6 cm (34% versus 10%, P = 0.03). All recurrences occurred within 2 years following treatment.

CONCLUSION

Combined-modality therapy for metastatic cutaneous squamous cell carcinoma to the axilla is recommended for high-risk patients, although outcomes remain modest. The key period for recurrence is within 2 years following treatment.

Risk factors for lymph node metastasis in cutaneous squamous cell carcinoma: a long-term retrospective study of Japanese patients

BACKGROUND

Cutaneous squamous cell carcinoma (CSCC) is one of the most common skin cancers. Prognosis is favorable following surgical resection of early-stage disease, but the management of the metastatic disease is challenging. Several prognostic risk factors have been described in the American Joint Committee on Cancer/the Union for International Cancer Control (UICC) 8th edition staging and the Brigham and Women's Hospital T classification system. However, their clinical validity in Asian populations is unclear because of racial differences in the clinical characteristics of CSCC. This study aimed to identify factors that could predict lymph node metastasis in Asian patients.

METHODS

This retrospective single-center study evaluated 540 patients with primary CSCC between 1989 and 2013. Five factors were evaluated for their ability to predict lymph node metastasis: maximum tumor diameter, tumor thickness, depth of invasion, degree of differentiation, and infiltrative growth pattern (INF).

RESULTS

Tumor diameter > 2 cm (p < 0.0001), tumor thickness > 6 mm (p < 0.0001), invasion beyond the subcutaneous fat (p < 0.0001), poor differentiation (p = 0.042), and INFc infiltration (p < 0.0001) were associated with lymph node metastasis in the univariate analyses. In the multivariate analysis, lymph node metastasis was independently associated with tumor size > 2 cm [hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.4-6.2; p = 0.006], tumor thickness > 6.0 mm (HR 2.9, 95% CI 1.3-6.4; p = 0.007), and invasion beyond the subcutaneous fat (HR 2.3, 95% CI 1.0-5.1; p = 0.045).

CONCLUSION

Larger tumor diameter, greater tumor thickness, and deeper invasion included in the UICC T classification system are associated with increased risks of lymph node metastasis from CSCC in Japanese patients.

Identifying risk factors for the prognosis of head and neck cutaneous squamous cell carcinoma: A systematic review and meta-analysis

In this study, we sought to identify the potential impacts of disease characteristics on the prognosis of cutaneous squamous cell carcinoma (cSCC). We searched the PubMed, EmBase, and Cochrane Library databases from their inception until February 2020 to identify studies that investigated the prognosis of cSCC. The pooled effect estimates were applied using odds ratios (OR) and 95% confidence intervals (CI) and were calculated using the random-effects model. Forty-three studies including a total of 21,530 patients and reporting 28,627 cases of cSCC were selected for the final meta-analysis. Poor differentiation (OR, 3.54; 95% CI, 2.30–5.46; P < 0.001), perineural invasion (OR, 3.27; 95% CI, 1.60–6.67; P = 0.001), Breslow greater than 2 mm (OR, 5.47; 95% CI, 2.63–11.37; P < 0.001), diameter greater than 20 mm (OR, 4.62; 95% CI, 2.95–7.23; P < 0.001), and location on temple (OR, 3.20; 95% CI, 1.12–9.15; P = 0.030) were associated with an increased risk of recurrence, whereas immunosuppression status and location on cheek, ear, or lip were not associated with the risk of recurrence. Poor differentiation (OR, 6.82; 95% CI, 4.66–9.99; P < 0.001); perineural invasion (OR, 7.15; 95% CI, 4.73–10.83; P < 0.001); Breslow greater than 2 mm (OR, 6.11; 95% CI, 4.05–9.21; P < 0.001); diameter greater than 20 mm (OR, 5.01; 95% CI, 2.56–9.80; P < 0.001); and location on ear (OR, 2.38; 95% CI, 1.39–4.09; P = 0.002), lip (OR, 2.15; 95% CI, 1.26–3.68; P = 0.005), and temple (OR, 2.77; 95% CI, 1.20–6.40; P = 0.017) were associated with an increased risk of metastasis, whereas immunosuppression status and location on cheek did not affect the risk of metastasis. Finally, poor differentiation (OR, 5.97; 95% CI, 1.82–19.62; P = 0.003), perineural invasion (OR, 6.64; 95% CI, 3.63–12.12; P < 0.001), and Breslow greater than 2 mm (OR, 3.42; 95% CI, 1.76–6.66; P < 0.001) were associated with an increased risk of disease-specific death, whereas diameter; immunosuppression status; and location on ear, lip, and temple did not affect the risk of disease-specific death. We found that differentiation, perineural invasion, depth, diameter, and location could affect the prognosis of cSCC. The potential role of other patient characteristics on the prognosis of cSCC should be identified in further large-scale prospective studies.

Skin Cancers of the Auricle: A Retrospective Analysis of 41 Patients

Objective

Skin cancers of the auricle usually present with challenges because of the unique anatomy and topography of the auricle and the behavior of the tumor. The purpose of this study was to evaluate the clinical and histopathological characteristics and the surgical outcomes in patients with skin cancer of the auricle.

Methods

Medical records of patients who underwent surgery for a skin cancer of the auricle at two different tertiary medical centers during 2010 to 2020 were reviewed retrospectively. Sociodemographic data of patients, tumor location and size, histopathological type and subtype, T-stage, recurrence, and reconstructive technique were evaluated.

Results

The study included 41 patients with skin cancers of the auricle. Thirty-six (87.8%) were male and five (12.2%) were female; with a male-to-female ratio of 7.2:1. The mean age of the patients was 71.4 (46-92) years. Eighteen (43.9%) tumors were basal cell carcinoma (BCC) and 17 (41.5%) tumors were cutaneous squamous cell carcinoma (cSCC). The most common subunit for tumor location was the helix (n=17, 41.5%). Wedge resection plus primary closure was the most common surgical technique (58.5%). Recurrent disease was detected in five patients (12.1%).

Conclusion

The frequency of the skin cancers of the auricle was remarkably high in men, and the helix was the most common subunit. Both BCC and cSCC were the most common histopathological types. Poor prognostic factors such as lymph node metastasis, perineural invasion, and recurrence were relatively common in patients with cSCC of the auricle.

UV biomarker genes for classification and risk stratification of cutaneous actinic keratoses and squamous cell carcinoma subtypes

Currently, there is no sensitive molecular test for identifying transformation-prone actinic keratoses (AKs) and aggressive squamous cell carcinoma (SCC) subtypes. Biomarker-based molecular testing represents a promising tool for risk stratifying these lesions. We evaluated the utility of a panel of ultraviolet (UV) radiation-biomarker genes in distinguishing between benign and transformation-prone AKs and SCCs. The expression of the UV-biomarker genes in 31 SCC and normal skin (NS) pairs and 10 AK/NS pairs was quantified using the NanoString nCounter system. Biomarker testing models were built using logistic regression models with leave-one-out cross validation in the training set. The best model to classify AKs versus SCCs (area under curve (AUC) 0.814, precision score 0.833, recall 0.714) was constructed using a top-ranked set of 13 UV-biomarker genes. Another model based on a 15-gene panel was developed to differentiate histologically concerning from less concerning SCCs (AUC 1, precision score 1, recall 0.714). Finally, 12 of the UV-biomarker genes were differentially expressed between AKs and SCCs, while 10 genes were uniquely expressed in the more concerning SCCs. UV-biomarker gene subsets demonstrate dynamic utility as molecular tools to classify and risk stratify AK and SCC lesions, which will complement histopathologic diagnosis to guide treatment of high-risk patients.

Primary Invasive Squamous Cell Carcinoma of the Foot

Malignant transformation of wounds is a rare complication that if missed can lead to loss of life or limb. This case report presents a rare invasive variant of squamous cell carcinoma presenting in the setting of a chronic wound complicated by osteomyelitis. This aggressive form of squamous cell carcinoma has a high growth rate and a high propensity for metastasis and recurrence. Early intervention greatly decreases the risk of metastasis and recurrence. We present the systematic evaluation and surgical management of an aggressive primary tumor occurring in the forefoot.

Phenformin Promotes Keratinocyte Differentiation via the Calcineurin/NFAT Pathway

Phenformin is a drug in the biguanide class that was previously used to treat type 2 diabetes. We have reported the antitumor activities of phenformin to enhance the efficacy of BRAF-MAPK kinase-extracellular signal-regulated kinase pathway inhibition and to inhibit myeloid-derived suppressor cells in various melanoma models. Here we demonstrate that phenformin suppresses tumor growth and promotes keratinocyte differentiation in the 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate two-stage skin carcinogenesis mouse model. Moreover, phenformin enhances the suspension-induced differentiation of mouse and human keratinocytes. Mechanistically, phenformin induces the nuclear translocation of NFATc1 in keratinocytes in an AMPK-dependent manner. Pharmacologic or genetic inhibition of calcineurin and NFAT signaling reverses the effects of phenformin on keratinocyte differentiation. Taken together, our study reveals an antitumor activity of phenformin to promote keratinocyte differentiation that warrants future translational efforts to repurpose phenformin for the treatment of cutaneous squamous cell carcinomas.

A review of terms used to define cutaneous squamous cell carcinoma with a poor prognosis

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer in humans and its incidence is both underestimated and on the rise. cSCC is referred to in the literature as high-risk cSCC, locally advanced cSCC, metastatic cSCC, advanced cSCC, and aggressive cSCC. These terms can give rise to confusion and are not always well defined. In this review, we aim to clarify the concepts underlying these terms with a view to standardizing the description of this tumor, something we believe is necessary in light of the new drugs that have been approved or are in development for cSCC.

AXIN2 and SNAIL expression predict the risk of recurrence in cutaneous squamous cell carcinoma after Mohs micrographic surgery

Recurrence is a common complication observed during cutaneous squamous cell carcinoma (cSCC) treatment; however, biomarkers for predicting recurrence in cSCC remain unknown. The present study aimed to investigate the predictive value of axis inhibition protein 2 (AXIN2) and SNAIL expression in cSCC recurrence. AXIN2 and SNAIL expression was evaluated using immunohistochemistry in 111 cSCC tissue samples obtained from 18 patients who presented recurrence (recurrence interval, 1–91 months) and 93 patients who did not experience recurrence following Mohs micrographic surgery (MMS) during the follow-up period (156 months). Nomogram construction was performed using patients' clinicopathological characteristics and AXIN2 and SNAIL protein expression. The results demonstrated that high AXIN2 (histoscore >100) and SNAIL (histoscore >100) expression was detected in 35 and 44 cSCC tissues, respectively. Furthermore, the expression levels of AXIN2 and SNAIL were significantly associated in patients with cSCC (P=0.001). AXIN2 and SNAIL expression levels were significantly associated with tumor size (P=0.021 and P=0.044, respectively) and recurrence of cSCC (P=0.017 and P=0.042, respectively). In addition, the results of the Kaplan-Meier curve analysis revealed that recurrence-free survival was significantly associated with tumor size (P=0.025), differentiation status (P<0.001), AXIN2 expression (P=0.001) and SNAIL expression (P=0.001). Furthermore, the results of the multivariate analysis demonstrated that age (P=0.043), AXIN2 expression (P=0.001) and SNAIL expression (P=0.045) were independent risk factors for cSCC recurrence in the present cohort. A nomogram for predicting the 1-, 2-, 3-, and 5-year recurrence-free survival was developed for patients with cSCC by including independent risk factors with a concordance index of 0.75. The results suggested that high AXIN2 and SNAIL expression may be considered as potential risk factors for cSCC recurrence. This nomogram may therefore be useful to assess the probability of recurrence in patients with cSCC following MMS.

Cutaneous Squamous Cell Carcinoma: Updates in Staging and Management

Cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in the United States. Outcomes are generally favorable, but a subset of cSCC is biologically distinct and requires a different approach because of its higher risk of local recurrence, metastasis, and death. This article focuses on the recent literature regarding identification of this high-risk subset, efforts to validate and improve the prognostic ability of staging systems, and updates in management.

Facial cutaneous squamous cell carcinoma - microscopic safety margins and their impact on developing local recurrences

OBJECTIVES

Surgical excision remains the treatment of choice for facial cutaneous squamous cell carcinoma (cSCC) despite there being no generally accepted diameter of clear margins. Therefore, the aim of this study was to evaluate the impact of microscopic clear margins diameter (mCMD) with respect to the development of local recurrences (LR).

MATERIALS AND METHODS

The medical records of 99 patients with a total of 142 cases of facial cSCC, who underwent surgical treatment between January 2010 and December 2015, were reviewed for demographic data and clinicopathological features.

RESULTS

100 cases were diagnosed as primary cSCC and 42 cases as secondary cSCC. Of these, nine (6.3%) developed LR. Mean time to LR was 20 months, with the cheek as the predominant site 55.5% (n = 5). Wound closure was either primary (56%) or secondary (44%), depending on the site. Although no significant correlation between mCMD and LR was found (r_Pearson = 0.029; r_Pearson = 0.015), >4.1 mm was shown to be a negative cut-off-value (horizontally and vertically) without LR (100% vs 0%).

CONCLUSIONS

Based on these results, however descriptive they are, the authors consider histological confirmation of clear margins to be necessary for reducing the formation of LR. Thus, consistent testing and histopathological reporting, in a multicentered effort, are needed to further clarify the role of mCMD in the development of cSCC-LR.

Risk factors for recurrence in cutaneous squamous cell carcinoma after Mohs micrographic surgery: A retrospective review of 237 Asian patients

Even after complete removal with Mohs micrographic surgery (MMS), cutaneous squamous cell carcinoma (cSCC) may recur; however, information about risk factors for recurrence in Asian patients is limited. This retrospective study reviewed cSCC patients treated with MMS at a single tertiary referral center from 2000 to 2017. Two hundred and thirty-seven patients were included and 36 showed recurrence (20 with local recurrence, 16 with distant metastasis). History of organ transplantation, diabetes, other malignancies and poorly differentiated histology correlated with cSCC recurrence. History of organ transplantation and cryotherapy at the cSCC site were related to higher local recurrence rates, and poor differentiation related to higher distant metastasis in Asian cSCC patients treated with MMS.

Aggressive Squamous Cell Carcinoma in Organ Transplant Recipients

Importance

Squamous cell carcinoma (SCC) is the most frequent malignant neoplasm found in solid organ transplant recipients and is associated with a more aggressive disease course and higher risk of metastasis and death than in the general population.

Objectives

To report the clinicopathologic features of and identify factors associated with aggressive SCC in solid organ transplant recipients.

Methods

This retrospective multicentric case series included 51 patients who underwent solid organ transplantation and were found to have aggressive SCC, defined by nodal or distant metastasis or death by local progression of primary SCC. Standard questionnaires were completed by the researchers between July 18, 2005, and January 1, 2015. Data were analyzed between February 22, 2016, and July 12, 2016.

Results

Of the 51 participants, 43 were men and 8 were women, with a median age of 51 years (range, 19-71 years) at time of transplantation and 62 years (range, 36-77 years) at time of diagnosis of aggressive SCC. The distribution of aggressive SCC was preferentially on the face (34 [67%]) and scalp (6 [12%]), followed by the upper extremities (6 [12%]). A total of 21 tumors (41%) were poorly differentiated, with a median tumor diameter of 18.0 mm (range, 4.0-64.0 mm) and median tumor depth of 6.2 mm (range, 1.0-20.0 mm). Perineural invasion was present in 20 patients (39%), while 23 (45%) showed a local recurrence. The 5-year overall survival rate was 23%, while 5-year disease-specific survival was 30.5%.

Conclusions and Relevance

Results of this case series suggest that anatomical site, differentiation, tumor diameter, tumor depth, and perineural invasion are important risk factors in aggressive SCC in solid organ transplant recipients.

Squamous Cell Carcinoma with Regional Metastasis to Axilla or Groin Lymph Nodes: a Multicenter Outcome Analysis

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) of the trunk/extremities with nodal metastasis represents a rare but significant clinical challenge. Treatment patterns and outcomes are poorly described.

PATIENTS AND METHODS

Patients with cSCC who developed axilla/groin lymph node metastasis and underwent curative-intent surgery between 2005 and 2015 were identified at four Canadian academic centers. Demographics, tumor characteristics, treatment patterns, recurrence rates, and mortality were described. Overall survival (OS) and disease-free survival (DFS) were calculated using Kaplan-Meier analysis. Predictors of survival and any recurrence were explored using Cox regression and logistic regression models, respectively.

RESULTS

Of 43 patients, 70% were male (median age 74 years). Median follow-up was 38 months. Median time to nodal metastasis was 11.3 months. Thirty-one and 12 patients had nodal metastasis to the axilla and groin, respectively. A total of 72% and 7% received adjuvant and neoadjuvant radiation, respectively, while 5% received adjuvant chemotherapy. Following surgery, 26% patients developed nodal and/or distant disease recurrence. Crude mortality rate was 39.5%. Mean OS was 5.3 years [95% confidence interval (CI) 3.9-6.8 years], and 5-year OS was 55.1%. Mean DFS was 4.8 years (95% CI 3.3-6.2 years), and five-year DFS was 49.3%. Any recurrence was the only independent predictor of death [p = 0.036, odds ratio (OR) = 29.5], and extracapsular extension (p = 0.028, OR = 189) and age (p = 0.017, OR = 0.823) were independent predictors of recurrence.

CONCLUSIONS

This represents the largest contemporary series to date of outcomes for patients with axilla/groin nodal metastases from cSCC. Despite aggressive treatment, outcomes remain modest, indicating the need for a continued multidisciplinary approach and integration of new systemic agents.

Prognostic value of inositol polyphosphate-5-phosphatase expression in recurrent and metastatic cutaneous squamous cell carcinoma

BACKGROUND

Inositol polyphosphate-5-phosphatase (INPP5A) has been shown to play a role in the progression of actinic keratosis to cutaneous squamous cell carcinoma (cSCC) and the progression of localized disease to metastatic disease. Currently, no cSCC biomarkers are able to risk stratify recurrent and metastatic disease.

OBJECTIVE

To determine the prognostic value of INPP5A expression in cSCC recurrent and metastatic disease.

METHODS

We conducted a multicenter, single-institutional, retrospective cohort study within the Mayo Clinic Health System on the use of immunohistochemical staining to examine cSCC INPP5A protein expression in primary tumors and recurrent and metastatic disease. Dermatologists and dermatopathologists were blinded to outcome.

RESULTS

Low staining expression of INPP5A in recurrent and metastatic disease tumors was associated with poor overall survival (OS) (31.0 months for low versus 62.0 months for high expression; P = .0272). A composite risk score (calculated as score of primary tumor + score of recurrent or metastatic disease tumor, with tumors with high expression scoring a zero and low expression a 1, score range 0-2) of 0 was predictive of improved OS compared with a composite risk score of ≥1 (hazard ratio 0.42, 95% confidence interval 0.21-0.84; P = .0113).

LIMITATIONS

This is a multicenter but single institution study of a white population.

CONCLUSION

Loss of INPP5A expression predicts poor OS in recurrent and metastatic disease of cSCC.

Review of systemic agents in the treatment of advanced cutaneous squamous cell carcinoma

Advanced cutaneous squamous cell carcinoma (cSCC) accounts for only 5% of all cases of cSCC but up to 60% of disease related deaths. Historically, this disease has lacked effective treatment options due to a combination of poor response rate, poor response durability and significant treatment-associated morbidity. Autumn of 2018 marked the first time ever that an agent received US FDA approval for advanced cSCC and the future is looking much brighter for this previously neglected patient population. The purpose of this article is to review the various systemic treatment options for advanced cSCC moving from the past to the present, highlighting their relative merits and shortcomings, and to briefly speculate on future developments in the field of advanced cSCC.

Current Basal and Squamous Cell Skin Cancer Management

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Characterize basal and squamous cell carcinomas as low or high risk based on size, location, histology, and clinical features. 2. Understand appropriate surgical margins in low- and high-risk lesions, and other management options, including Mohs micrographic surgery, electrodissection and curettage, topical agents, cryotherapy, photodynamic therapy, and radiation therapy. 3. Discuss adjuvant therapies for locally advanced and metastatic disease, including radiation therapy, chemotherapy, and targeted therapies such as hedgehog pathway inhibitors. 4. Educate patients on preventive measures such as skin examinations, sun protection, oral retinoids, and oral nicotinamide (vitamin B3). 5. Devise a reconstructive plan once clear oncologic margins are obtained.

SUMMARY

With the growing incidence of basal and squamous cell carcinoma, there is an increasing demand for appropriate oncologic management and aesthetic reconstruction. The goal of this CME article is to provide a foundation of knowledge to accurately diagnose, stage, and treat nonmelanoma skin cancers. In addition, it provides the practicing plastic surgeon alternate tools for managing these skin lesions, including topical agents, destructive therapies, and radiation therapy. Lastly, reconstructive plans for selected soft-tissue defects are discussed.

Nodal staging of high-risk cutaneous squamous cell carcinoma

BACKGROUND

While progress has been made in defining the clinical and histopathologic features of high-risk cutaneous squamous cell carcinoma (HRcSCC), optimal staging guidelines remain elusive.

OBJECTIVE

We seek to guide clinical practice regarding nodal staging options for patients with HRcSCC via review of evolving definitions of HRcSCC, nodal staging options, and how nodal staging may impact treatment and affect outcomes.

METHODS

This was a retrospective review of the published peer-reviewed literature regarding risk stratification, nodal staging, and treatment and outcomes for patients with HRcSCC via PubMed.

RESULTS

For patients without clinical lymphadenopathy, based on literature from head and neck SCC, preoperative nodal staging with ultrasonography may be more useful than computed tomography or magnetic resonance imaging. Early nodal disease is usually curable, and therefore obtaining a sentinel lymph node biopsy specimen may be considered in those with negative imaging while we await studies of nodal staging outcomes.

LIMITATIONS

More data are needed to validate the relationships between primary tumor stage and sentinel lymph node biopsy status and to determine if early detection of nodal disease impacts survival for patients with HRcSCC.

CONCLUSION

It is reasonable to consider nodal staging for patients with HRcSCC (Brigham and Women's Hospital stage T2b and T3) in the absence of clinically palpable lymphadenopathy via radiographic imaging and, if negative, sentinel lymph node biopsy.

Metastatic squamous cell carcinoma of known and unknown primary origin treated with axillary or inguinal lymphadenectomy

BACKGROUND

Metastatic squamous cell carcinoma (SCC) to the axillary or inguinal lymph nodes from an unknown primary source is rarely encountered. We sought to evaluate a cohort of patients with metastatic SCC managed by lymphadenectomy to determine their survival and to determine which clinicopathologic factors were associated with outcome.

METHODS

All patients undergoing axillary or inguinal lymphadenectomy for SCC at our institution were identified retrospectively. Patients were stratified by unknown primary (UP) vs known skin primary (KP) tumors. Pertinent data on patient, tumor, and treatment variables was collected.

RESULTS

We identified 51 patients who met inclusion criteria. Of those, 20 patients (39%) had UP metastatic SCC and 31 patients (61%) had KP. The 5-year overall survival for UP was 65%, as compared to 49% for KP (p = 0.16). Cumulative incidence of recurrence was 46%. Cox regression failed to demonstrate a significant association between KP vs UP, HPV status, chemotherapy, or radiation with survival.

CONCLUSIONS

Nearly two-thirds of patients undergoing axillary or inguinal lymphadenectomy for metastatic SCC of unknown primary were alive five years following the procedure.

Clinical Remission of Cutaneous Squamous Cell Carcinoma of the Auricle with Cetuximab and Nivolumab

Cutaneous squamous cell carcinomas (SCC) affecting the regions of the head and neck can be challenging to resect surgically and refractory to chemotherapy or radiation therapy. Consequently; the treatment of squamous cell carcinomas of the skin is a focus of current research. One such advancement is immunotherapy. Herein we describe clinical remission of invasive, poorly differentiated squamous cell carcinoma of the pre-auricular region with external auditory canal involvement using cetuximab, an epidermal growth factor receptor (EGFR) antibody; and nivolumab, a programmed death receptor-1 (PD-1) antibody. Such durable and comprehensive disease resolution demonstrates the therapeutic potential of cetuximab and nivolumab in surgically challenging, treatment-resistant cutaneous squamous cell carcinoma.

Identifying drug resistant cancer cells using microbubble well arrays

Drug resistance is a characteristic of tumor initiating cells that can give rise to metastatic disease. In this work we demonstrate the use of microbubble well arrays as a cell culture platform to enumerate and characterize drug resistant cells in a human derived tumorigenic squamous cell carcinoma cell line. The spherical architecture and compliant hydrophobic composition of the microbubble well favors single cell survival, clonal proliferation and formation of spheres that do not grow on standard tissue culture plastic and are resistant to cisplatin. Spheres form in isolation and in microbubble wells containing proliferating cells and to some degree they stain positive for common stem cell markers CD44 and CD133. Spheres are also observed in cellularized primary human tumors cultured in microbubble arrays. This proof-of-concept study illustrates the potential for microbubble array technology to enumerate cancer cells resistant to standard care drugs with the ability to test alternative drug combinations. This capability can be developed for designing patient specific treatment strategies. Recovery of drug-resistant cells will allow a more full characterization of their gene expression profile thereby expanding our fundamental knowledge and ability to develop new targets to fight metastatic disease.

Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a malignant neoplasm of the skin characterized by an aberrant proliferation of keratinocytes. Cutaneous SCC is the second most common malignancy globally, and usually arises in the chronically sun-damaged skin of elderly white individuals. From a pathologist's perspective, it is important to differentiate cSCC from the benign and reactive squamoproliferative lesions and identify the high-risk features associated with aggressive tumor behavior. In this article, we provide an up-to-date overview of cSCC along with its precursor lesions and important histologic variants, with a particular emphasis on the histopathologic features and molecular pathogenesis.