Validating 4 Staging Systems for Cutaneous Squamous Cell Carcinoma Using Population-Based Data: A Nested Case-Control Study

Cancer-associated fibroblast activation predicts progression, metastasis, and prognosis of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer and the metastatic disease is associated with poor prognosis. Cancer-associated fibroblasts (CAFs) promote progression of cancer, but their role in cSCC is largely unknown. We examined the potential of CAF markers in the assessment of metastasis risk and prognosis of primary cSCC. We utilized multiplexed fluorescence immunohistochemistry for profiling CAF landscape in metastatic and non-metastatic primary human cSCCs, in metastases, and in premalignant epidermal lesions. Quantitative high-resolution image analysis was performed with two separate panels of antibodies for CAF markers and results were correlated with clinical and histopathological parameters including disease-specific mortality. Increased stromal expression of fibroblast activation protein (FAP), α-smooth muscle actin, and secreted protein acidic and rich in cysteine (SPARC) were associated with progression to invasive cSCC. Elevation of FAP and platelet-derived growth factor receptor-β (PDGFRβ) expression was associated with metastasis risk of primary cSCCs. High expression of PDGFRβ and periostin correlated with poor prognosis. Multimarker combination defined CAF subset, PDGFRα-/PDGFRβ+/FAP+, was associated with invasion and metastasis, and independently predicted poor disease-specific survival. These results identify high PDGFRβ expression alone and multimarker combination PDGFRα-/PDGFRβ+/FAP+ by CAFs as potential biomarkers for risk of metastasis and poor prognosis.

Artificial intelligence-empowered cellular morphometric risk score improves prognostic stratification of cutaneous squamous cell carcinoma

BACKGROUND

Risk stratification of cutaneous squamous cell carcinoma (cSCC) is essential for managing patients.

OBJECTIVES

To determine if artificial intelligence and machine learning might help to stratify patients with cSCC by risk using more than solely clinical and histopathological factors.

METHODS

We retrieved a retrospective cohort of 104 patients whose cSCCs had been excised with clear margins. Clinical and histopathological risk factors were evaluated. Haematoxylin and eosin-stained slides were scanned and analysed by an algorithm based on the stacked predictive sparse decomposition technique. Cellular morphometric biomarkers (CMBs) were identified via machine learning and used to derive a cellular morphometric risk score (CMRS) that classified cSCCs into clusters of differential prognoses. Concordance analysis, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated and compared with results obtained with the Brigham and Women's Hospital (BWH) staging system. The performance of the combination of the BWH staging system and the CMBs was also analysed.

RESULTS

There were no differences among the CMRS groups in terms of clinical and histopathological risk factors and T-stage assignment, but there were significant differences in prognosis. Combining the CMRS with BWH staging systems increased distinctiveness and improved prognostic performance. C-indices were 0.91 local recurrence and 0.91 for nodal metastasis when combining the two approaches. The NPV was 94.41% and 96.00%, the PPV was 36.36% and 41.67%, and accuracy reached 86.75% and 89.16%, respectively, with the combined approach.

CONCLUSIONS

CMRS is helpful for cSCC risk stratification beyond classic clinical and histopathological risk features. Combining the information from the CMRS and the BWH staging system offers outstanding prognostic performance for patients with high-risk cSCC.

Lymph node metastasis in cutaneous squamous cell carcinoma of the head and neck

BACKGROUND

The study aimed to assess the impact of parotid lymph nodes (LNs) on the prognosis of patients with cutaneous squamous cell carcinomas of the head and neck (HNcSCC), and to develop an alternative LN assessment method to enhance locoregional control (LRC) and overall survival (OS) stratification.

METHODS

We retrospectively enrolled patients with surgically treated HNcSCC. Primary outcome variables were LRC and OS. The influence of parotid LNs and different LN assessment methods on prognosis was analyzed using Cox models, and comparisons were made using the C-index, Akaike Information Criterion, and Bayesian Information Criterion.

RESULTS

A total of 126 patients were included. Both intraparotid and periparotid LN statuses significantly linked with prognosis. The presence of extranodal extension (ENE) in cervical LNs, rather than parotid LNs, was predictive of decreased LRC and OS. In the Cox analysis, only N3 of the AJCC N classification, when compared to N0, showed reduced LRC and OS. In comparison to N0P1, only N0P3/N1P1 and N2P2/N2P3 of the O'Brien staging system tended to predict poorer LRC, with no subgroup emerging as an independent predictor for OS. The proposed LN assessment method, based on the number of metastatic LNs and ENE status in cervical LNs, demonstrated superior performance in terms of C-index, Akaike Information Criterion, and Bayesian Information Criterion compared to other systems.

CONCLUSION

Parotid LNs were significant determinants of prognosis in metastatic HNcSCC. The novel LN assessment method proposed (1-2 vs. 3-4 vs. 5 + or ENE) displayed similar survival stratification to the AJCC N and O'Brien staging systems.

Performance of Staging Systems for Non-Head and Neck Cutaneous Squamous Cell Carcinoma

BACKGROUND

The performance of staging systems in non-head and neck cutaneous squamous cell carcinomas has not been well established.

OBJECTIVE

To evaluate the performance of the American Joint Committee on Cancer 8th Edition and Brigham and Women's Hospital staging systems in non-head and neck squamous cell carcinomas.

MATERIALS AND METHODS

Eligible tumors were identified and staged from an existing retrospective database. Cumulative incidence function curves of any poor outcome were generated. Distinctiveness, sensitivity, specificity, positive and negative predictive value, and concordance index were calculated.

RESULTS

1,042 primary tumors were included, with 38 resulting in any poor outcome and 16 in any major poor outcome. High-stage tumors represented 2.2% and 3.5% of tumors; these accounted for 10/38 of the poor outcomes (26.3%) and 8/16 of the major poor outcomes (50%). High-stage tumors predicted major poor outcomes with a sensitivity of 0.5 and specificity of 0.99 for the Brigham and Women's Hospital system, and a sensitivity of 0.5 and specificity of 0.97 for the American Joint Committee on Cancer 8th edition system. The concordance index for both was 0.74.

CONCLUSION

Current staging systems can be used to predict poor outcomes in cutaneous squamous cell carcinomas off the head and neck.

Distinguishing Keratoacanthoma from Well-Differentiated Cutaneous Squamous Cell Carcinoma Using Single-Cell Spatial Pathology

Keratoacanthoma (KA) is a common keratinocyte neoplasm that is regularly classified as a type of cutaneous squamous cell carcinoma (cSCC) despite demonstrating benign behavior. Differentiating KA from well-differentiated cSCC is difficult in many cases due to the substantial overlap of clinical and histological features. Currently, no reliable discriminating markers have been defined, and consequently, KAs are often treated similarly to cSCC, creating unnecessary surgical morbidity and healthcare costs. In this study, we used RNA sequencing to identify key differences in transcriptomes between KA and cSCC, which suggested divergent keratinocyte populations between each tumor. Imaging mass cytometry was then used to identify single-cell tissue characteristics, including cellular phenotype, frequency, topography, functional status, and interactions between KA and well-differentiated cSCC. We found that cSCC had significantly increased proportions of Ki67+ keratinocytes among tumor keratinocytes, which were dispersed significantly throughout non-basal keratinocyte communities. In cSCC, regulatory T-cells were more prevalent and held greater suppressive capacity. Furthermore, cSCC regulatory T-cells, tumor-associated macrophages, and fibroblasts had significant associations with Ki67+ keratinocytes as opposed to avoidances with KA, indicating a more immunosuppressive environment. Our data suggest that multicellular spatial features can serve as a foundation to enhance the histological discrimination of ambiguous KA and cSCC lesions.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: Diagnostics and prevention-Update 2023

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in white populations, accounting for 20% of all cutaneous malignancies. Overall, cSCC mostly has very good prognosis after treatment, with 5-year cure rates greater than 90%. Despite the overall favourable prognosis and the proportionally rare deaths, cSCC is associated with a high total number of deaths due to its high incidence. A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV) and the European Organization of Research and Treatment of Cancer (EORTC), was formed to update recommendations on cSCC, based on current literature and expert consensus. Part 1 of the guidelines addresses the updates on classification, epidemiology, diagnosis, risk stratification, staging and prevention in immunocompetent as well as immunosuppressed patients.

Desmoplasia in cutaneous squamous cell carcinoma with perineural invasion

This study examines the rate of desmoplasia in cutaneous squamous cell carcinoma with perineural invasion and the associated clinical outcomes.

Personalised decision making to predict absolute metastatic risk in cutaneous squamous cell carcinoma: development and validation of a clinico-pathological model

Background

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer, affecting more than 2 million people worldwide yearly and metastasising in 2-5% of patients. However, current clinical staging systems do not provide estimates of absolute metastatic risk, hence missing the opportunity for more personalised treatment advice. We aimed to develop a clinico-pathological model that predicts the probability of metastasis in patients with cSCC.

Methods

Nationwide cohorts from (1) all patients with a first primary cSCC in The Netherlands in 2007-2008 and (2) all patients with a cSCC in 2013-2015 in England were used to derive nested case-control cohorts. Pathology records of primary cSCCs that originated a loco-regional or distant metastasis were identified, and these cSCCs were matched to primary cSCCs of controls without metastasis (1:1 ratio). The model was developed on the Dutch cohort (n = 390) using a weighted Cox regression model with backward selection and validated on the English cohort (n = 696). Model performance was assessed using weighted versions of the C-index, calibration metrics, and decision curve analysis; and compared to the Brigham and Women's Hospital (BWH) and the American Joint Committee on Cancer (AJCC) staging systems. Members of the multidisciplinary Skin Cancer Outcomes (SCOUT) consortium were surveyed to interpret metastatic risk cutoffs in a clinical context.

Findings

Eight out of eleven clinico-pathological variables were selected. The model showed good discriminative ability, with an optimism-corrected C-index of 0.80 (95% Confidence interval (CI) 0.75-0.85) in the development cohort and a C-index of 0.84 (95% CI 0.81-0.87) in the validation cohort. Model predictions were well-calibrated: the calibration slope was 0.96 (95% CI 0.76-1.16) in the validation cohort. Decision curve analysis showed improved net benefit compared to current staging systems, particularly for thresholds relevant for decisions on follow-up and adjuvant treatment. The model is available as an online web-based calculator (https://emc-dermatology.shinyapps.io/cscc-abs-met-risk/).

Interpretation

This validated model assigns personalised metastatic risk predictions to patients with cSCC, using routinely reported histological and patient-specific risk factors. The model can empower clinicians and healthcare systems in identifying patients with high-risk cSCC and offering personalised care/treatment and follow-up. Use of the model for clinical decision-making in different patient populations must be further investigated.

Funding

PPP Allowance made available by Health-Holland, Top Sector Life Sciences & Health, to stimulate public-private partnerships.

Rates of Second Tumor, Metastasis, and Death From Cutaneous Squamous Cell Carcinoma in Patients With and Without Transplant-Associated Immunosuppression

Importance

Cutaneous squamous cell carcinoma (cSCC) may occur with multiple primary tumors, metastasize, and cause death both in immunocompetent and immunosuppressed patients.

Objective

To study the rates of second cSCC, metastasis, and death from cSCC in patients with and without organ transplant-associated immunosuppressive treatment.

Design, Setting, and Participants

This population-based, nationwide cohort study used Cancer Registry of Norway data from 47 992 individuals diagnosed with cSCC at 18 years or older between January 1, 1968, and December 31, 2020. Data were analyzed between November 24, 2021, and November 15, 2022.

Exposures

Receipt of a solid organ transplant at Oslo University Hospital between 1968 and 2012 followed by long-term immunosuppressive treatment.

Main Outcomes and Measures

Absolute rates of second cSCC, metastasis, and death from cSCC were calculated per 1000 person-years with 95% CIs. Hazard ratios (HRs) estimated using Cox proportional hazard regression were adjusted for age, sex, and year of first cSCC diagnosis.

Results

The study cohort comprised 1208 organ transplant recipients (OTRs) (median age, 66 years [range, 27-89 years]; 882 men [73.0%] and 326 women [27.0%]) and 46 784 non-OTRs (median age, 79 years [range, 18-106 years]; 25 406 men [54.3%] and 21 378 women [45.7%]). The rate of a second cSCC per 1000 person-years was 30.9 (95% CI, 30.2-31.6) in non-OTRs and 250.6 (95% CI, 232.2-270.1) in OTRs, with OTRs having a 4.3-fold increased rate in the adjusted analysis. The metastasis rate per 1000 person-years was 2.8 (95% CI, 2.6-3.0) in non-OTRs and 4.8 (95% CI, 3.4-6.7) in OTRs, with OTRs having a 1.5-fold increased rate in the adjusted analysis. A total of 30 451 deaths were observed, of which 29 895 (98.2%) were from causes other than cSCC. Death from cSCC was observed in 516 non-OTRs (1.1%) and 40 OTRs (3.3%). The rate of death from cSCC per 1000 person-years was 1.7 (95% CI, 1.5-1.8) in non-OTRs and 5.4 (95% CI, 3.9-7.4) in OTRs, with OTRs having a 5.5-fold increased rate in the adjusted analysis.

Conclusions and Relevance

In this cohort study, OTRs with cSCC had significantly higher rates of second cSCC, metastasis, and death from cSCC than non-OTRs with cSCC, although most patients with cSCC in both groups died from causes other than cSCC. These findings are relevant for the planning of follow-up of patients with cSCC and for skin cancer services.

Recommendations for risk stratification of periocular squamous cell carcinoma

Periocular squamous cell carcinoma is a common cutaneous malignancy with generally favorable outcomes; however, the periocular region is intrinsically a high-risk location, and there exist a subset of lesions with a propensity for poor outcomes. Orbital invasion, intracranial perineural spread, nodal and distant metastasis are feared complications. There are several staging systems for eyelid carcinoma and cutaneous squamous cell carcinoma, but the definition of high-risk lesions remains heterogeneous. It is unclear exactly which lesions can be safely deescalated, and which require nodal evaluation and adjuvant multimodal therapy. We seek to answer these questions by summarizing the literature on clinicopathologic variables, molecular markers, and gene profiling tests in periocular squamous cell carcinoma, with the extrapolation of data from the cutaneous squamous cell carcinoma literature. Standardized pathology reports with information on tumor dimensions, histological subtype and grade, perineural invasion, and lymphovascular invasion should become uniform. Integration with gene expression profiling assessments will individualize and improve the predictive accuracy of risk stratification tools to ultimately inform multidisciplinary decision-making.

Staging System Performance and Clinical Outcomes for Cutaneous Squamous Cell Carcinoma of the Ear: A Single-Center Retrospective Study

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) of the ear is associated with poor outcomes. No studies have evaluated current staging system performance in this specific location.

OBJECTIVE

Describe clinicopathologic characteristics and outcomes of ear cSCC and evaluate the performance of current staging systems.

METHODS

Retrospective study including cases diagnosed and treated at a cancer center from January 2000 to December 2014. Demographic, clinical, and pathologic data were collected from clinical records. Biopsy slides were rereviewed and patients were staged according to the American Joint Committee on Cancer (AJCC) seventh, eighth, and Brigham Women's Hospital (BWH) staging.

RESULTS

Of 125 patients, the mean age at diagnosis was 71.9 years (SD 12.5), with most men (89.6%, n = 112). Median follow-up was 22.3 months. Local recurrence and survival risk factors were similar to cSCC outside the ear. The Akaike's Information Criterion (AIC) estimates showed that the BWH system better predicted outcomes than the AJCC seventh, and the AJCC eighth, with AIC values of 189.9, 270.5, and 274.1, respectively. Limitations of the study include retrospective design, single center study, and no control group.

CONCLUSION

Current staging systems perform well at stratifying risk in ear cSCC.

Comparative Performance of Four Staging Classifications to Select «High-Risk» Head and Neck Cutaneous Squamous Cell Carcinomas

BACKGROUND

Many classifications exist to select patients with "high-risk" head and neck cutaneous squamous cell carcinoma (HNCSCC).

OBJECTIVE

To compare the performance of the Brigham and Women's Hospital (BWH) classification with the performance of the American Joint Committee on Cancer 8th Edition (AJCC8), the Union for International Cancer Control 8th Edition (UICC8), and the National Comprehensive Cancer Network (NCCN) classifications.

METHODS

In this single-center retrospective study, HNCSCC resected in a tertiary care center were classified as "low-risk" or "high-risk" tumors according to the four classifications. Rates of local recurrence (LR), lymph node recurrence (NR), and disease-specific death (DSD) were collected. The performance of each classification was then calculated in terms of homogeneity, monotonicity, and discrimination and compared.

RESULTS

Two hundred and seventeen HNCSCC from 160 patients, with a mean age of 80 years, were included. For predicting the risk of any poor outcome and risk of NR, the BWH classification had the best specificity and positive predictive value. However, its concordance index was not significantly higher than that of the AJCC8 and UICC8 classifications. The NCCN classification was the least discriminant.

CONCLUSIONS AND RELEVANCE

This study suggests that the BWH classification is the most appropriate for predicting the risk of poor outcomes in patients with HNCSCC when compared with the NCCN, UICC8, and AJCC8 classifications.

Resection of Skin Cancer Resulting in Free Vascularized Tissue Reconstruction: Always a Therapeutic Failure?

The globally increasing incidence of cutaneous malignancies leads, in parallel, to increasing numbers of locally advanced skin cancer resulting in reconstructive surgery. Reasons for locally advanced skin cancer may be a patient's neglect or aggressive tumor growth, such as desmoplastic growth or perineural invasion. This study investigates characteristics of cutaneous malignancies requiring microsurgical reconstruction with the aim of identifying possible pitfalls and improving diagnostic and therapeutic processes. A retrospective data analysis from 2015 to 2020 was conducted. Seventeen patients (n = 17) were included. The mean age at reconstructive surgery was 68.5 (±13) years. The majority of patients (14/17, 82%) presented with recurrent skin cancer. The most common histological entity was squamous cell carcinoma (10/17, 59%). All neoplasms showed at least one of the following histopathological characteristics: desmoplastic growth (12/17, 71%), perineural invasion (6/17, 35%), or tumor thickness of at least 6 mm (9/17, 53%). The mean number of surgical resections until cancer-free resection margins (R0) were achieved was 2.4 (±0.7). The local recurrence rate and the rate of distant metastases were 36%. Identified high-risk neoplastic characteristics, such as desmoplastic growth, perineural invasion, and a tumor depth of at least 6 mm, require a more extensive surgical treatment without concerns about defect size.

The Prognostic Value and Clinical Utility of the 40-Gene Expression Profile (40-GEP) Test in Cutaneous Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

BACKGROUND

The current tumor staging systems for cutaneous squamous cell carcinoma (cSCC) are considered inadequate and insufficient for evaluating the risk of metastasis and for identifying patients at high risk of cSCC. This meta-analysis aimed to assess the prognostic significance of a 40-gene expression profile (40-GEP) both independently and integrated with clinicopathologic risk factors and established staging systems (American Joint Committee on Cancer, eighth edition (AJCC8) and Brigham and Women's Hospital (BWH)).

METHODS

Electronic databases, including PubMed (MEDLINE), Embase, the Cochrane Library, and Google Scholar, were systematically searched to identify cohort studies and randomized controlled trials on evaluations of the prediction value of 40-GEP in cSCC patients up to January 2023. The metastatic risk analysis of a given 40-GEP class combined with tumor stage and/or other clinicopathologic risk factors was based upon log hazard ratios (HRs) and their standard error (SE). Heterogeneity and subgroup analyses were performed, and data quality was assessed.

RESULTS

A total of 1019 patients from three cohort studies were included in this meta-analysis. The overall three-year metastatic-free survival rates were 92.4%, 78.9%, and 45.4% for class 1 (low risk), class 2A (Intermediate risk), and class 2B (high risk) 40-GEP, respectively, indicating a significant variation in survival rates between the risk classification groups. The pooled positive predictive value was significantly higher in class 2B when compared to AJCC8 or BWH. The subgroup analyses demonstrated significant superiority of integrating 40-GEP with clinicopathologic risk factors or AJCC8/BWH, especially for class 2B patients.

CONCLUSIONS

The integration of 40-GEP with staging systems can improve the identification of cSCC patients at high risk of metastasis, potentially leading to improved care and outcomes, especially in the high-risk class 2B group.

Staging cutaneous squamous cell carcinoma in an Irish cohort

We review staging systems for cutaneous squamous cell carcinoma.

Clinical practicality of reporting cutaneous squamous cell carcinoma risk factors at the time of Mohs surgery

Multiple high-risk factors have been associated with poor outcomes in cutaneous squamous cell carcinoma, including immunosuppression, poor differentiation, depth, diameter, and perineural invasion. While many of these are included in major staging systems, their measurement and reporting vary considerably in clinical practice. We performed a survey study of fellowship-trained Mohs surgeons to explore their attitudes and practices related to recording squamous cell carcinoma high-risk factors and staging information at the time of Mohs. An anonymous Qualtrics survey of 25 questions was distributed to the American College of Mohs Surgery membership listserv. There were 107 complete surveys (response rate 7.1%), with over 95% of subjects from the United States. Fifty-five percent had been practicing 10 years or less, 28% between 11 and 20 years, and the remainder greater than 20 years. Fifty-seven percent were in private or group practices, and 43% were in academia. Nearly all respondents consistently report tumor recurrence (100%), location (100%), immunosuppression (94%), and diameter (93%). Only 70% grade differentiation for every squamous cell carcinoma case. Sixty-six percent of participants consistently record anatomic depth, while only 2% always or almost always record Breslow depth. Although 96% of respondents almost always or always record perineural invasion, only 34% consistently record nerve diameter. Forty-three percent reported that they never or rarely stage cutaneous squamous cell carcinomas, whereas 43% often, almost always, or always stage. In conclusion, certain high-risk factors, such as differentiation, Breslow depth, and stage, are recorded inconsistently by Mohs surgeons. Several participants commented that they prefer to send a central debulk to dermatopathology to assess staging parameters in all tumors with high-risk features. While this strategy may be useful in some practice settings, Mohs surgeons possess the skills necessary to perform a central debulk analysis themselves at the time of Mohs. Whether performed at the time of Mohs or by dermatopathology, assessing high-risk features and accurately staging cutaneous squamous cell carcinoma is paramount to detecting tumors at higher risk of poor outcomes.

Impact of AJCC 8 pT staging in cutaneous head and neck squamous cell carcinoma in a nonselected real-world patient sample

OBJECTIVE

Our aim was to evaluate characteristics associated with worse survival and the effectiveness of AJCC 8 in a real-world cohort of HNCSCC from South Brazil.

METHODS

A 10-year retrospective cohort study (2011-2020) at a tertiary care center comprising 647 HNCSCC excised from 435 patients.

RESULTS

At multivariable analysis, ear/nose/zygomatic or periorbital site, compromised or exiguous margins, and advanced pT stage were independent factors associated to DFS, while age, pN, and loco-regional recurrence were independent factors associated to DSS. Cox-regression multivariable models showed that the pT stage was statistically significant for the DFS, but not DSS. A significant distinction was only observed between T1 and T2.

CONCLUSION

It was only in the lower categories of AJCC 8 (T1 and T2) that we were able to demonstrate the ability to stratify tumors with a significant risk of poor disease-related outcomes.

A nomogram combining clinical factors and biomarkers for predicting the recurrence of high-risk cutaneous squamous cell carcinoma

Background

Although determining the recurrence of cutaneous squamous cell carcinoma (cSCC) is important, currently suggested systems and single biomarkers have limited power for predicting recurrence.

Objective

In this study, combinations of clinical factors and biomarkers were adapted into a nomogram to construct a powerful risk prediction model.

Methods

The study included 145 cSCC patients treated with Mohs micrographic surgery. Clinical factors were reviewed, and immunohistochemistry was performed using tumor tissue samples. A nomogram was constructed by combining meaningful clinical factors and protein markers.

Results

Among the various factors, four clinical factors (tumor size, organ transplantation history, poor differentiation, and invasion into subcutaneous fat) and two biomarkers (Axin2 and p53) were selected and combined into a nomogram. The concordance index (C-index) of the nomogram for predicting recurrence was 0.809, which was higher than that for the American Joint Committee on Cancer (AJCC) 7th, AJCC 8th, Brigham and Women’s Hospital, and Breuninger staging systems in the patient data set.

Conclusion

A nomogram model that included both clinical factors and biomarkers was much more powerful than previous systems for predicting cSCC recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10213-2.

Real-world Evidence Shows Clinicians Appropriately Use the Prognostic 40-gene Expression Profile (40-GEP) Test for High-risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients

Treatment decisions for patients with cutaneous squamous cell carcinoma (cSCC) are traditionally based upon clinicopathologic risk factors and staging systems. Due to the accuracy limitations of these resources in predicting poor outcomes, there is a clinically significant need for more accurate methods of risk assessment. The 40-gene expression profile (40-GEP) test was developed to augment metastatic risk prediction of high-risk cSCC patients and has been validated in two independent, multi-center studies involving over 1,000 patients. This study substantiates that the 40-GEP is appropriately utilized by clinicians and that the personalized risk-stratification results are impactful in guiding risk-aligned patient management.

Identification of metastatic primary cutaneous squamous cell carcinoma utilizing artificial intelligence analysis of whole slide images

Cutaneous squamous cell carcinoma (cSCC) harbors metastatic potential and causes mortality. However, clinical assessment of metastasis risk is challenging. We approached this challenge by harnessing artificial intelligence (AI) algorithm to identify metastatic primary cSCCs. Residual neural network-architectures were trained with cross-validation to identify metastatic tumors on clinician annotated, hematoxylin and eosin-stained whole slide images representing primary non-metastatic and metastatic cSCCs (n = 104). Metastatic primary tumors were divided into two subgroups, which metastasize rapidly (≤ 180 days) (n = 22) or slowly (> 180 days) (n = 23) after primary tumor detection. Final model was able to predict whether primary tumor was non-metastatic or rapidly metastatic with slide-level area under the receiver operating characteristic curve (AUROC) of 0.747. Furthermore, risk factor (RF) model including prediction by AI, Clark’s level and tumor diameter provided higher AUROC (0.917) than other RF models and predicted high 5-year disease specific survival (DSS) for patients with cSCC with 0 or 1 RFs (100% and 95.7%) and poor DSS for patients with cSCCs with 2 or 3 RFs (41.7% and 40.0%). These results indicate, that AI recognizes unknown morphological features associated with metastasis and may provide added value to clinical assessment of metastasis risk and prognosis of primary cSCC.

Local Tumor Infiltration and Locoregional Recurrence in Desmoplastic Cutaneous Squamous Cell Carcinoma

BACKGROUND

Perusal of the literature of cutaneous squamous cell carcinoma (SCC) reveals that the role of the desmoplastic subtype is indistinct. Data on local infiltration and recurrence are inconsistent dependent on surgical technique, histological method, and investigated collective.

OBJECTIVE

The aim of the study was to analyze local infiltration and locoregional recurrence of the desmoplastic subtype under a uniform procedure.

METHODS AND MATERIALS

Between 2005 and 2015, 320 SCCs were analyzed and histological sections of all tumors were examined. Data collection included locoregional recurrence, metastasis rate, and tumor-specific death. The median follow-up was 36.5 months.

RESULTS

The desmoplastic subtype required significant more re-excisions (70.0% vs 23.9%, p < .001), more interventions until tumor-free margins were achieved (maximal 6 vs 2; p < .001), showed more widespread tumor infiltration with larger excisional margins (median 9 mm, 2-51 mm vs median 4 mm, 1-10 mm; p < .001), and a 5-fold higher local recurrence rate (26.7% vs 5.0%, p < .001). The metastasis rate (16.6% vs 2.3%, p < .001) was increased.

CONCLUSION

The desmoplastic subtype is characterized by a widespread local infiltration associated with perineural infiltration. It seems to be a marker for decreased histological detectability with a high rate of locoregional recurrence and metastasis.

Immunotherapy to Avoid Orbital Exenteration in Patients With Cutaneous Squamous Cell Carcinoma

Background

Cutaneous squamous cell carcinoma (CSCC) of the head and neck can require complex and disfiguring surgery in order to achieve cure, which can be morbid and negatively impact patient quality of life. The management of advanced CSCC has been revolutionized by immunotherapy with current clinical trials also exploring its role in the neoadjuvant and adjuvant settings. Patients may decline morbid curative surgery, such as orbital exenteration, and the outcomes of immunotherapy use in this unique group of patients require further investigation.

Methods

We reviewed the records of 119 patients treated at a major Australian quaternary oncology centre with immunotherapy (either cemiplimab or pembrolizumab) for advanced CSCC.

Results

We identified 7 patients recommended curative surgery involving orbital exenteration after multidisciplinary discussion, who declined surgery due to concerns about morbidity and/or disfigurement. All 7 patients demonstrated a response to treatment, and six avoided orbital exenteration. Two patients experienced pseudoprogression.

Conclusions

The management of CSCC can be complex and requires the input of a multidisciplinary team. Immunotherapy to avoid or reduce the extent of morbid definitive surgery is an emerging treatment option.

Current Methods and Caveats to Risk Factor Assessment in Cutaneous Squamous Cell Carcinoma (cSCC): A Narrative Review

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer, and the number of deaths due to cSCC is estimated to be greater than the number attributed to melanoma. While the majority of cSCC tumors are resectable with clear margins by standard excision practices, some lesions exhibit high-risk factors for which there is evidence of their association with recurrence, metastasis, and disease-specific death. The most commonly used staging systems and guidelines in the USA for cSCC are based on these clinical and pathologic high-risk factors; however, these are limited in their ability to predict adverse events, thus posing a challenge for implementing risk-directed patient management. Since the development of local recurrence and/or metastasis has a profound impact on the survival of patients with cSCC, accurate identification of patients at high risk for poor outcomes is critical, potentially allowing for early and appropriate adjuvant therapy. This review summarizes the current cSCC literature with a focus on how differing clinical assessments within each of the five selected risk factors (perineural invasion, differentiation, depth of invasion, size, and location) can influence the evaluation of patient outcomes, along with summarizing the utility of staging and guidelines, and highlighting the potential for molecular tools to improve upon cSCC risk assessment.

Validation of Four Cutaneous Squamous Cell Carcinoma Staging Systems Using Nationwide Data

Background

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer worldwide with relatively low metastatic potential (2–5%). Developments in therapeutic options have highlighted the need to better identify high‐risk patients who could benefit from closer surveillance, adjuvant therapies and baseline/follow‐up imaging, while at the same time safely omitting low‐risk patients from further follow‐up. Controversy remains regarding the predictive performance of current cSCC staging systems and which methodology to adopt.

Objectives

To validate the performance of four cSCC staging systems [American Joint Committee on Cancer 8th edition (AJCC8), Brigham and Women’s Hospital (BWH), Tübingen and Salamanca T3 refinement] in predicting metastasis using a nationwide cohort.

Methods

A nested case–control study using data from the National Disease Registration Service, England, 2013–2015 was conducted. Metastatic cSCC cases were identified using an algorithm to identify all potential cases for manual review. These were 1 : 1 matched on follow‐up time to nonmetastatic controls randomly selected from 2013. Staging systems were analysed for distinctiveness, homogeneity, monotonicity, specificity, positive predictive value (PPV), negative predictive value (NPV) and c‐index.

Results

We included 887 metastatic cSCC cases and 887 nonmetastatic cSCC controls. The BWH system showed the highest specificity [92.8%, 95% confidence interval (CI) 90.8–94.3%, PPV (13.2%, 95% CI 10.6–16.2) and c‐index (0.84, 95% CI 0.82–0.86). The AJCC8 showed superior NPV (99.2%, 95% CI 99.2–99.3), homogeneity and monotonicity compared with the BWH and Tübingen diameter and thickness classifications (P < 0.001). Salamanca refinement did not show any improvement in AJCC8 T3 cSCC staging.

Conclusions

We validated four cSCC staging systems using the largest nationwide dataset of metastatic cSCC so far. Although the BWH system showed the highest overall discriminative ability, PPV was low for all staging systems, which shows the need for further improvement and refining of current cSCC staging systems.

Assessing the accuracy of computed tomography in detecting bony invasion and thickness of squamous cell carcinoma of the scalp

OBJECTIVES

The aim of this study was to ascertain the accuracy of computed tomography (CT) in assessing the presence of bony involvement and thickness of squamous cell carcinoma (SCC) of the scalp.

METHODS

A single-centre retrospective chart review was carried out. Inclusion criteria were scalp SCC, CT between January 2008 and 2018, and the availability of a reference test. Reference tests were either histology, surgical notes or clinical notes. Tabular assessment of accuracy was performed and Student's t-test, Mann-Whitney U test and Fisher exact test were used in univariable analysis. Accuracy of thickness measurement was calculated using the limits of agreement method, and linear regression was used to examine trend.

RESULTS

Thirty-nine patients were included. Most patients were male (74.4%), white (97.4%), not immunosuppressed (66.6%) and had poorly differentiated tumours (33.3%). The most common tumour sites were the vertex (28.2%) and temporal region (23.1%). Sensitivity of CT in detecting presence or absence of bony invasion of scalp SCC was 76.9% (95% CI 46.2-94.9%) and specificity was 96.2% (95% CI 80.4-99.9%). Overall accuracy was 89.7% (95% CI 75.8-97.1%), positive predictive value was 90.1% (95% CI 58.7-99.8%) and negative predictive value was 89.3% (95% CI 71.8-97.7%). No significant differences were found comparing patients with an accurate or inaccurate CT scan. Thickness on CT was found to be consistent with histological thickness at the 95% confidence level.

CONCLUSIONS

CT is accurate at assessing the presence of bony involvement and thickness of scalp SCC. This study was limited somewhat by small sample size.

Evidence-Based Consensus Recommendations for the Evolving Treatment of Patients with High-Risk and Advanced Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma is the second most common skin cancer in the United States. Currently, there is no standardized management approach for patients with cutaneous squamous cell carcinoma who develop metastatic or locally advanced disease and are not candidates for curative surgery or curative radiation. To address this issue, the Expert Cutaneous Squamous Cell Carcinoma Leadership program convened an expert steering committee to develop evidence-based consensus recommendations on the basis of a large, structured literature review. Consensus was achieved through modified Delphi methodology. The steering committee included five dermatologists, three medical oncologists, two head and neck surgeons, one radiation oncologist, and a patient advocacy group representative. The steering committee aligned on the following clinical topics: diagnosis and identification of patients considered not candidates for surgery; staging systems and risk stratification in cutaneous squamous cell carcinoma; the role of radiation therapy, surgery, and systemic therapy in the management of advanced disease, with a focus on immunotherapy; referral patterns; survivorship care; and inclusion of the patient's perspective. Consensus was achieved on 34 recommendations addressing 12 key clinical questions. The Expert Cutaneous Squamous Cell Carcinoma Leadership steering committee's evidence-based consensus recommendations may provide healthcare professionals with practically oriented guidance to help optimize outcomes for patients with advanced cutaneous squamous cell carcinoma.

Hide-and-seek: Neurotropic squamous cell carcinoma of the periorbital region - a series of five cases and review of the literature

Squamous cell carcinoma is the second most common malignancy of the skin after basal cell carcinoma and mainly found in sun‐exposed areas such as the face. This mostly locally destructive malignancy may show invasive growth and insidious mechanisms of dissemination such as perineural invasion. Periorbital squamous cell carcinoma is associated with perineural invasion in up to 14 % of cases. Specifically in this region, the proximity to cranial nerves and therefore the associated risk of progression to the central nervous system are associated with poor prognosis. The clinically concealed character of this entity often leads to a delay in diagnosis and consequently makes complete resection and reconstruction demanding. Careful clinical evaluation often hints at perineural invasion before obtaining histology.

Aside from presenting five challenging cases, this work analyzes risk factors, clinical as well as histological features, and treatment options for periorbital squamous cell carcinoma with perineural invasion.

Hide-and-seek: Neurotropes Plattenepithelkarzinom der periorbitalen Region - eine Fallserie und Übersichtsarbeit aktueller Literatur

Das Plattenepithelkarzinom ist nach dem Basalzellkarzinom das zweithäufigste Malignom der Haut und wird vorwiegend an sonnenexponierten Stellen wie der Gesichtshaut diagnostiziert. Diese meist lokal destruktiv wachsende Malignität kann durchaus auch invasives Wachstumsverhalten, wie perineurale Ausbreitungsmechanismen, aufweisen. Das Plattenepithelkarzinom der periorbitalen Region ist in bis zu 14 % der Fälle mit perineuraler Invasion assoziiert. Vor allem in diesem Bereich birgt die anatomische Nähe zu den Hirnnerven das Risiko einer Progression Richtung zentrales Nervensystem, was mit einer schlechteren Prognose assoziiert ist. Der klinisch unauffällige Charakter dieser Entität resultiert oft in einer Verzögerung der definitiven Diagnosestellung, wodurch die vollständige Resektion und anschließende Rekonstruktion erschwert werden. Eine aufmerksame klinische Evaluierung kann bereits vor Erlangen histologischer Befunde Hinweise für ein perineurales Wachstum liefern. Neben fünf herausfordernden Fällen analysiert diese Arbeit Risikofaktoren, klinische als auch histologische Merkmale und Behandlungsoptionen des periorbitalen Plattenepithelkarzinoms mit perineuraler Invasion.

Cutaneous squamous cell carcinoma staging may influence management in users: A survey study

Purpose

This study aims to determine whether there is consensus regarding staging and management of cutaneous squamous cell carcinoma (CSCC) across the various specialties that manage this disease.

Materials and Methods

A survey regarding CSCC high‐risk features, staging, and management was created and emailed to cutaneous oncology experts including dermatology, head and neck surgery/surgical oncology, radiation oncology, and medical oncology.

Results

One hundred fifty‐six (46%) of 357 invited physicians completed the survey. Depth of invasion (92%), perineural invasion (99%), histologic differentiation (85%), and patient immunosuppression (90%) achieved consensus (>80%) as high‐risk features of CSCC. Dermatologists were more likely to also choose clinical tumor diameter (79% vs. 54%) and histology (99% vs. 66%) as a high‐risk feature. Dermatologists were also more likely to utilize the Brigham and Women's Hospital (BWH) staging system alone or in conjunction with American Joint Committee on Cancer (AJCC) (71%), whereas other cancer specialists (OCS) tend to use only AJCC (71%). Respondents considered AJCC T3 and higher (90%) and BWH T2b and higher (100%) to be high risk and when they consider radiologic imaging, sentinel lymph node biopsy, post‐operative radiation therapy, and increased follow‐up. Notably, a large number of respondents do not use staging systems or tumor stage to determine treatment options beyond surgery in high‐risk CSCC.

Conclusion

This survey study highlights areas of consensus and differences regarding the definition of high‐risk features of CSCC, staging approaches, and management patterns between dermatologists and OCS. High‐risk CSCC is defined as, but not limited to, BWH T2b and higher and AJCC T3 and higher, and these thresholds can be used to identify cases for which treatment beyond surgery may be considered. Dermatologists are more likely to utilize BWH staging, likely because BWH validation studies showing advantages over AJCC were published in dermatology journals and discussed at dermatology meetings. Additional data are necessary to develop a comprehensive risk‐based management approach for CSCC.

Concordance of Squamous Cell Carcinoma Histologic Grading Among Dermatopathologists and Mohs Surgeons

BACKGROUND

Current staging systems for cutaneous squamous cell carcinoma (cSCC) incorporate histologic grade. There are no universally agreed on criteria to define differentiation for cSCC.

OBJECTIVE

To determine the interrater and intrarater reliability among dermatopathologists and Mohs surgeons in grading histological differentiation for cSCC.

METHODS AND MATERIALS

One hundred thirty-one archived slides were selected. Three dermatopathologists and 3 Mohs surgeons graded the tumors in a blinded manner (Round 1). In an attempt to improve concordance, all 6 participants were then asked to regrade the tumors based on a devised quantitative grading scale (Round 2).

RESULTS

For Round 1, overall κ was 0.56 corresponding to a weak agreement. κ for well, moderate, and poorly differentiated tumors was 0.68, 0.39, and 0.59, respectively, corresponding to moderate, minimal, and weak concordance. For Round 2 of the study, overall κ was 0.60, with κ = 0.75, 0.46, and 0.61 for well, moderate, and poorly differentiated tumors, respectively. Overall intrarater reliability was 0.70 (κ = 0.70, 0.77, 0.68, 0.71, 0.56, and 0.75), corresponding to a moderate concordance.

CONCLUSION

Overall concordance for cSCC histologic grading is weak to moderate among the experimental group. Substantial differences in concordance exist among histological degrees of differentiation, with lowest agreement in moderately differentiated tumors.

Epidemiology of advanced cutaneous squamous cell carcinoma

Cutaneous invasive squamous cell carcinoma (cSCC) most commonly presents as a typically indolent tumour with five-year cure rates of >90%. Advanced cSCC has been defined as locally advanced or metastatic (locoregional or distant) cSCC. The epidemiological data on advanced cSCC are rare due to underreporting or exclusion of cSCC from national cancer registries. Although the frequency of local recurrence has been reported, there is no clear evidence on the incidence or mortality of locally advanced cSCCs, e.g. locally infiltrating or locally recurrent cSCCs that are not further amenable to curative surgery or radiotherapy. This gap of knowledge on the epidemiology of locally advanced cSCC, highlights the need for standardisation in defining and reporting both locally advanced and metastatic cSCC. Even though metastatic cSCCs are a small part of cSCCs (3%-5%), their aggressive characteristics contribute to significant morbidity, higher mortality and are those likely to require systemic treatments. Locally recurrent and metastatic cSCC may occur more frequently in high-risk cSCCs (up to 35%). The site of metastasis involves in the vast majority the regional lymph nodes, with the head and neck lymph nodes or parotid most commonly affected. Metastasis occurs mostly within 2-3 years of the primary cSCC diagnosis. The knowledge of the incidence and prognosis of advanced cSCC and the risk stratification of patients, who may progress to advanced cSCC, emerge as pressing research areas with important implications for cost-efficiency planning and optimisation of patient care.

The Role of p53 in Progression of Cutaneous Squamous Cell Carcinoma

Skin cancers are the most common types of cancer worldwide, and their incidence is increasing. Melanoma, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC) are the three major types of skin cancer. Melanoma originates from melanocytes, whereas BCC and cSCC originate from epidermal keratinocytes and are therefore called keratinocyte carcinomas. Chronic exposure to ultraviolet radiation (UVR) is a common risk factor for skin cancers, but they differ with respect to oncogenic mutational profiles and alterations in cellular signaling pathways. cSCC is the most common metastatic skin cancer, and it is associated with poor prognosis in the advanced stage. An important early event in cSCC development is mutation of the TP53 gene and inactivation of the tumor suppressor function of the tumor protein 53 gene (TP53) in epidermal keratinocytes, which then leads to accumulation of additional oncogenic mutations. Additional genomic and proteomic alterations are required for the progression of premalignant lesion, actinic keratosis, to invasive and metastatic cSCC. Recently, the role of p53 in the invasion of cSCC has also been elucidated. In this review, the role of p53 in the progression of cSCC and as potential new therapeutic target for cSCC will be discussed.

Review of Perineural Invasion in Keratinocyte Carcinomas

Perineural invasion is an infiltrative process of peripheral nerves by the primary neoplasm within the immediate vicinity. Aggressive forms of keratinocyte carcinomas, such as basal cell and squamous cell carcinomas, may feature perineural invasion, which is often associated with tumor recurrence and poorer prognosis. Diagnosis requires a high clinical suspicion. Imaging and histopathology are used to assess for extent of disease while surgical excision with complete circumferential peripheral and margin assessment is the treatment goal. However, there is still significant uncertainty about adjuvant chemotherapy and definitive management guidelines. Here, we summarize the current understanding of this complex pathogenic process, the clinical presentation, and the significance of perineural inflammation. We also discuss the recommendations about staging, prognosis, adjuvant radiotherapy, and general guidelines for managing keratinocyte carcinomas with perineural invasion. A better understanding of perineural invasion is essential to improve diagnosis, tailor interventions, and mitigate patient morbidity and mortality.

Pilot Phase II Trial of Neoadjuvant Immunotherapy in Locoregionally Advanced, Resectable Cutaneous Squamous Cell Carcinoma of the Head and Neck

PURPOSE

In locoregionally advanced, resectable cutaneous squamous cell carcinoma of the head and neck (CSCC-HN), surgery followed by radiotherapy is standard but can be cosmetically and functionally devastating, and many patients will have recurrence.

PATIENTS AND METHODS

Newly diagnosed or recurrent stage III-IVA CSCC-HN patients amenable to curative-intent surgery received two cycles of neoadjuvant PD-1 inhibition. The primary endpoint was ORR per RECIST 1.1. Secondary endpoints included pathologic response [pathologic complete response (pCR) or major pathologic response (MPR; ≤10% viable tumor)], safety, DSS, DFS, and OS. Exploratory endpoints included immune biomarkers of response.

RESULTS

Of 20 patients enrolled, 7 had recurrent disease. While only 6 patients [30%; 95% confidence interval (CI), 11.9-54.3] had partial responses by RECIST, 14 patients (70%; 95% CI, 45.7-88.1) had a pCR (n = 11) or MPR (n = 3). No SAEs ocurred during or after the neoadjuvant treatment. At a median follow-up of 22.6 months (95% CI, 21.7-26.1), one patient progressed and died, one died without disease, and two developed recurrence. The 12-month DSS, DFS, and OS rates were 95% (95% CI, 85.9-100), 89.5% (95% CI, 76.7-100), and 95% (95% CI, 85.9-100), respectively. Gene expression studies revealed an inflamed tumor microenvironment in patients with pCR or MPR, and CyTOF analyses demonstrated a memory CD8+ T-cell cluster enriched in patients with pCR.

CONCLUSIONS

Neoadjuvant immunotherapy in locoregionally advanced, resectable CSCC-HN is safe and induces a high pathologic response rate. Pathologic responses were associated with an inflamed tumor microenvironment.

Cost effectiveness of intermediate-risk squamous cell carcinoma treated with Mohs micrographic surgery compared with wide local excision

BACKGROUND

The efficacy of Mohs micrographic surgery (MMS) in treating cutaneous squamous cell carcinoma has been demonstrated. The cost effectiveness of MMS has rarely been studied to support the perceived higher cost.

OBJECTIVE

Perform a cost-effectiveness analysis to determine whether MMS is cost effective over wide local excision (WLE) for Brigham and Women's Hospital tumor stage T2a cutaneous squamous cell carcinoma over a 5-year period.

METHODS

A Markov model with a 5-year time horizon was created using variables from published data. Costs in United States dollars and quality-adjusted life-years (QALY) were calculated.

RESULTS

MMS was $333.83 less expensive ($4365.57 [95% CI, $3664.68-$6901.66] vs $4699.41 [95% CI, $3782.94-$10,019.31]) than WLE. MMS gained 2.22 weeks of perfect health (3.776 QALY [95% CI, 3.774-3.777] for MMS and 3.733 QALY [95% CI, 3.728-3.777]) over 5 years. The incremental cost-effectiveness ratio was -$7,822.19. MMS had a 99.9% probability of being more cost effective than WLE. Annualized savings of choosing MMS over WLE would be $200 million and over 25,000 QALY. MMS could cost 3.1 times its current rate and remain cost effective.

LIMITATIONS

Relied on data from external retrospective sources.

CONCLUSION

MMS is less costly and more effective than WLE and should be strongly considered for stage T2a cSCC, given improvements in costs and QALY.

High-Risk Cutaneous Squamous Cell Carcinoma of the Head and Neck: A Clinical Review

BACKGROUND

Given the rapidly evolving nature of the field, the current state of "high-risk" head and neck cutaneous squamous cell carcinoma (HNcSCC) is poorly characterized.

METHODS

Narrative review of the epidemiology, diagnosis, workup, risk stratification, staging and treatment of high-risk HNcSCC.

RESULTS

Clinical and pathologic risk factors for adverse HNcSCC outcomes are nuanced (e.g., immunosuppression and perineural invasion). Frequent changes in adverse prognosticators have outpaced population-based registries and the variables they track, restricting our understanding of the epidemiology of HNcSCC and inhibiting control of the disease. Current heterogeneous staging and risk stratification systems are largely derived from institutional data, compromising their external validity. In the absence of staging system consensus, tumor designations such as "high risk" and "advanced" are variably used and insufficiently precise to guide management. Evidence guiding treatment of high-risk HNcSCC with curative intent is also suboptimal. For patients with incurable disease, an array of trials are evaluating the impact of immunotherapy, targeted biologic therapy, and other novel agents.

CONCLUSION

Population-based registries that broadly track updated, nuanced, adverse clinicopathologic risk factors, and outcomes are needed to guide development of improved staging systems. Design and development of randomized controlled trials (RCTs) in advanced-stage HNcSCC populations are needed to evaluate (1) observation, sentinel lymph node biopsy, or elective neck dissection for management of the cN0 neck, (2) indications for surgery plus adjuvant radiation versus adjuvant chemoradiation, and (3) the role of immunotherapy in treatment with curative intent. Considering these knowledge gaps, the authors explore a potential high-risk HNcSCC treatment framework.

Clinician perspectives on the factors influencing prognostic stratification by the American Joint Commission on Cancer Head and Neck Cutaneous Squamous Cell Carcinoma Staging

BACKGROUND

The eighth edition of the American Joint Committee on Cancer Staging Manual includes a staging system for head and neck cutaneous squamous cell carcinoma for the first time. The pN categories for head and neck cutaneous squamous cell carcinoma and mucosal squamous cell carcinoma are identical, despite the vastly different biological behavior of these diseases. This study aimed to survey head and neck cancer specialists' views regarding the clinical utility of the American Joint Committee on Cancer Staging Manual for head and neck cutaneous squamous cell carcinoma and to identify avenues for improvement.

DESIGN

An electronic survey of 19 questions relating to the prognostic utility of the staging system was designed based on the findings of a literature review. The survey was distributed internationally to specialists managing head and neck cutaneous squamous cell carcinoma.

RESULTS

Literature review identified 9 articles describing primary research relevant to the performance of the American Joint Committee on Cancer Staging Manual for head and neck cutaneous squamous cell carcinoma, which recognized a lack of homogeneity, monotonicity, and distinctiveness in the pN staging system. One hundred and five survey responses were received: 71% indicated that mucosal and head and neck cutaneous squamous cell carcinoma require different nodal staging categories; 63% indicated that immunosuppression should be included in the staging system; 70% thought that soft tissue metastases portend a worse prognosis compared with extranodal extension; 38% almost never saw pN3a tumors; and 40% felt that the N stage is a poor predictor of survival.

CONCLUSION

The views of head and neck cancer specialists across disciplines and countries align with evidence suggesting that head and neck cutaneous squamous cell carcinoma merits a staging system distinct from mucosal squamous cell carcinoma, that immunosuppression should be considered in prognostication, and that the use of extranodal extension should be modified.

Brigham and Women's Hospital tumor classification system for basal cell carcinoma identifies patients with risk of metastasis and death

BACKGROUND

Despite approximately 4400 locally advanced US cases annually, high-stage basal cell carcinoma (BCC) is ill-defined.

OBJECTIVE

To develop a tumor (T) staging system for BCC that will predict metastasis/death and compare its performance with that of the American Joint Committee on Cancer 8th edition (AJCC8) T-staging system.

METHODS

Brigham and Women's Hospital (BWH) T staging was developed from a previously published nested cohort of 488 primary BCCs. Tumors were staged via BWH and AJCC8 T-staging systems, and predictions of metastasis and/or death were compared.

RESULTS

The BWH and AJCC8 T-staging systems both captured all metastases/deaths in high T stages (BWH, T2; AJCC8, T3/T4). BWH T2 included 54% fewer cases ≥2 cm than AJCC8 T3/T4. BWH had a higher specificity (0.92 vs 0.80; P < .001) and positive predictive value (24% vs 11%, P < .001) for identifying cases at risk for metastasis/death, and the C-statistic was superior for BWH (P < .001). The BWH T2 10-year cumulative incidence of metastasis/death was 37% (95% confidence interval, 21%-60%).

LIMITATIONS

Two-center cohort.

CONCLUSIONS

BWH and AJCC 8 BCC staging both capture all metastases and deaths in the upper stages. However, BWH staging does so in half the number of cases, thus minimizing inappropriate up-staging. The risk of metastasis or death in BWH T2 BCC is sufficient to warrant surveillance for recurrence and clinical trials of adjuvant therapy.

Performance of Salamanca refinement of the T3-AJCC8 versus the Brigham and Women's Hospital and Tübingen alternative staging systems for high-risk cutaneous squamous cell carcinoma

INTRODUCTION

The Brigham and Women's Hospital and the Tübingen cutaneous squamous cell carcinoma (SCC) stratification systems propose different criteria from the American Joint Committee on Cancer, eighth edition. Our group identified prognostic subgroups within T3 stage according to the American Joint Committee on Cancer eighth edition's classification, the most common classification for high-risk cutaneous SCCs.

OBJECTIVE

To compare the performance and prognostic accuracy of these staging systems in a subset of high-risk cutaneous SCCs.

METHODS

Homogeneity, monotonicity, and McNemar tests for pairwise comparisons were assessed. Distinctiveness and relative risk of poor outcome were calculated by stage. Prognostic accuracy was compared with respect to quality (Akaike and Bayesian information criteria), concordance (Harrell C-index and Gönen and Heller concordance probability estimate), and predictive accuracy (sensitivity, specificity, negative predictive value, positive predictive value, and global accuracy).

RESULTS

The Brigham and Women's Hospital and Salamanca systems were more distinctive, homogeneous, and monotonic than the Tübingen system. The Tübingen system was the most specific, whereas the Salamanca and Brigham and Women's Hospital systems were more sensitive. Negative predictive value was high in all 3 systems, but positive predictive value and accuracy were low overall.

CONCLUSIONS

Alternative staging systems may partially overcome the heterogeneity and low prognostic accuracy of the American Joint Committee on Cancer, eighth edition and enable high-risk cutaneous SCCs to be stratified more reliably, but their prognostic accuracy is still low. Considering the accumulation of risk factors may improve high-risk cutaneous SCC risk stratification.

Validation of the American Joint Committee on Cancer Staging in Squamous Cell Carcinoma of the Vermilion Lip

BACKGROUND

The vermilion lip is a unique anatomical junction between cutaneous and mucosal surfaces. Squamous cell carcinoma (SCC) of the vermilion lip (vlSCC) was previously classified as oral SCC (oSCC) under the American Joint Committee on Cancer (AJCC) 7th edition (AJCC7), but has been recategorized as a cutaneous SCC of the head and neck (HNcSCC) in the AJCC 8th edition (AJCC8). We investigated the locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) for the various pathological T categories and disease stages of vlSCC as per AJCC8.

METHODS

We performed a retrospective cohort study of 297 patients diagnosed with vlSCC between January 2004 and February 2019. For this study, vlSCC cases were staged according to both AJCC7 and AJCC8. Kaplan-Meier survival curves and Cox regression models were used to analyze differences in LRC, DFS, and OS between each pT category and disease stage, and log-rank tests were performed for subgroup analysis.

RESULTS

Restaging of vlSCC using the AJCC8 resulted in 19% of patients being upstaged to pT3, and 16% being upstaged to stage III. No patients were downstaged in pT stage or overall stage.

CONCLUSIONS

Our study shows that when the AJCC8 HNcSCC staging system is applied to vlSCC, there are important aberrations leading to unwarranted upstaging of pT1 and redundancy of pT2. Understanding of these limitations are important in considering treatment escalation.

Identification of proteins associated with development of metastasis from cutaneous squamous cell carcinomas (cSCCs) via proteomic analysis of primary cSCCs

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers capable of metastasizing. Proteomic analysis of cSCCs can provide insight into the biological processes responsible for metastasis, as well as future therapeutic targets and prognostic biomarkers.

OBJECTIVES

To identify proteins associated with development of metastasis in cSCC.

METHODS

A proteomic-based approach was employed on 105 completely excised, primary cSCCs, comprising 52 that had metastasized (P-M) and 53 that had not metastasized at 5 years post-surgery (P-NM). Formalin-fixed, paraffin-embedded cSCCs were microdissected and subjected to proteomic profiling after one-dimensional (1D), and separately two-dimensional (2D), liquid chromatography fractionation.

RESULTS

A discovery set of 24 P-Ms and 24 P-NMs showed 144 significantly differentially expressed proteins, including 33 proteins identified via both 1D and 2D separation, between P-Ms and P-NMs. Several differentially expressed proteins were also associated with survival in SCCs of other organs. The findings were verified by multiple reaction monitoring on six peptides from two proteins, annexin A5 (ANXA5) and dolichyl-diphosphooligosaccharide-protein glycosyltransferase noncatalytic subunit (DDOST), in the discovery group and validated on a separate cohort (n = 57). Increased expression of ANXA5 and DDOST was associated with reduced time to metastasis in cSCC and decreased survival in cervical and oropharyngeal cancer. A prediction model using ANXA5 and DDOST had an area under the curve of 0·93 (confidence interval 0·83-1·00), an accuracy of 91·2% and higher sensitivity and specificity than cSCC staging systems currently in clinical use.

CONCLUSIONS

This study highlights that increased expression of two proteins, ANXA5 and DDOST, is significantly associated with poorer clinical outcomes in cSCC.