Pinch Grafts Versus Second Intention Wound Healing for Mohs Micrographic Surgery Defects Below the Knee: A Prospective Randomized Trial.

BACKGROUND: The surgical management of leg wounds following skin cancer extirpation is challenging. Pinch grafting (PG) is a technique that has been rarely described in the reconstruction of acute surgical wounds. OBJECTIVE: The purpose of this study was to evaluate whether PG resulted in faster healing times for below the knee wounds following Mohs micrographic surgery (MMS) when compared with second intention healing (SIH). MATERIALS AND METHODS: This was a prospective randomized trial of patients with post-Mohs micrographic surgical wounds of the lower extremity who were randomized either to receive pinch grafts or to heal by second intention. Patients were followed through a combination of in-person and virtual visits until their wounds were completely reepithelialized. RESULTS: Median time to wound healing was 36 days in the PG group versus 56 days for the SIH group, representing a 56% improvement in healing time. There were no differences in complications between the 2 groups with trends toward decreased rates of pain and infection in the PG group. CONCLUSION: PG is an effective simple method to hasten the healing of lower extremity wounds following MMS.

The utility of artificial intelligence platforms for patient-generated questions in Mohs micrographic surgery: a multi-national, blinded expert panel evaluation.

BACKGROUND: Artificial intelligence (AI) and large language models (LLMs) transform how patients inform themselves. LLMs offer potential as educational tools, but their quality depends upon the information generated. Current literature examining AI as an informational tool in dermatology has been limited in evaluating AI's multifaceted roles and diversity of opinions. Here, we evaluate LLMs as a patient-educational tool for Mohs micrographic surgery (MMS) in and out of the clinic utilizing an international expert panel. METHODS: The most common patient MMS questions were extracted from Google and transposed into two LLMs and Google's search engine. 15 MMS surgeons evaluated the generated responses, examining their appropriateness as a patient-facing informational platform, sufficiency of response in a clinical environment, and accuracy of content generated. Validated scales were employed to assess the comprehensibility of each response. RESULTS: The majority of reviewers deemed all LLM responses appropriate. 75% of responses were rated as mostly accurate or higher. ChatGPT had the highest mean accuracy. The majority of the panel deemed 33% of responses sufficient for clinical practice. The mean comprehensibility scores for all platforms indicated a required 10th-grade reading level. CONCLUSIONS: LLM-generated responses were rated as appropriate patient informational sources and mostly accurate in their content. However, these platforms may not provide sufficient information to function in a clinical environment, and complex comprehensibility may represent a barrier to utilization. As the popularity of these platforms increases, it is important for dermatologists to be aware of these limitations.

Mohs for Melanoma: A Review of MART-1 Frozen Section Interpretation.

BACKGROUND: Mohs surgery for melanoma has been performed for many decades, but advances in the use of immunohistochemistry with frozen sections during Mohs surgery have allowed for more accurate, reliable, and efficient margin assessment with improved local control of the disease. OBJECTIVE: To describe the use of MART-1 in treating melanoma with Mohs surgery and serve as a primer for the Mohs surgeon adding melanoma cases to their repertoire. MATERIALS AND METHODS: Review of the literature and discussion of experience with Mohs for melanoma. RESULTS: Practical approach and pitfalls when assessing margins using MART-1 immunohistochemistry during Mohs surgery for the treatment of melanoma. CONCLUSION: Mohs for melanoma is an expanding field-education of Mohs surgeons and increasing the practice of this technique has the potential to improve patient outcomes.

Integrating the 40-Gene Expression Profile (40-GEP) Test Improves Metastatic Risk-Stratification Within Clinically Relevant Subgroups of High-Risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients.

INTRODUCTION: The validated 40-gene expression profile (40-GEP) test independently stratifies risk of regional or distant metastasis for cutaneous squamous cell carcinoma (cSCC) tumors with high-risk clinicopathologic features. This study evaluated the stratification of risk by the 40-GEP test in a large cohort of tumors with one or more high-risk factors and in clinically relevant subgroups, including tumors within National Comprehensive Cancer Network (NCCN) high- and very-high-risk groups, lower-stage BWH T1 and T2a tumors, and patients > 65 years old. METHODS: This multicenter (n = 58) performance study of the 40-GEP included 897 patients. Kaplan-Meier analyses were performed to assess risk stratification profiles for 40-GEP Class 1 (low), Class 2A (higher) and Class 2B (highest) risk groups, while nested Cox regression models were used to compare risk prediction of clinicopathologic risk classification systems versus risk classification systems in combination with 40-GEP. RESULTS: Patients classified as 40-GEP Class 1, Class 2A, or Class 2B had significantly different metastatic risk profiles (p < 0.0001). Integrating 40-GEP results into models with individual clinicopathologic risk factors or risk classification systems (Brigham and Women's Hospital, American Joint Committee on Cancer Staging Manual, 8th Edition) and NCCN demonstrated significant improvement in accuracy for prediction of metastatic events (ANOVA for model deviance, p < 0.0001 for all models). CONCLUSION: The 40-GEP test demonstrates accurate, independent, clinically actionable stratification of metastatic risk and improves predictive accuracy when integrated into risk classification systems. The improved accuracy of risk assessment when including tumor biology via the 40-GEP test ensures more risk-aligned, personalized patient management decisions.

Clinical Characteristics of Marginally Recurrent Melanoma After Primary Excision: A Multisite Retrospective Analysis of 140 Cases Referred for Mohs Surgery.

BACKGROUND: Marginally recurrent melanoma (MRM) manifests immediately adjacent to or within a scar and arises from incomplete tumor clearance after primary treatment. Little is known about the progression and treatment of MRM after all forms of excision. OBJECTIVE: To determine the invasive growth potential, tumor-stage progression, and outcomes of those with MRM. METHODS: One hundred forty patients with MRM were collected from 5 practice databases. All patients were treated with Mohs micrographic surgery. They were evaluated for Breslow depth and tumor stage change from the time of primary treatment and recurrent treatment. RESULTS: Of 101 cases initially treated as melanoma in situ, 13 (12.9%) marginally recurred with invasive disease at the time of Mohs micrographic surgery. The median thickness of these recurrent melanomas was 0.58 mm. Of 39 cases initially treated as invasive melanoma, 10 (25.6%) marginally recurred with a greater Breslow depth. The median increase in thickness from initial treatment to recurrence was 1.31 mm. CONCLUSION: Marginally recurrent melanoma retains its invasive growth potential. This can lead to Breslow depth increase, tumor-stage progression, and a worse prognosis on recurrence. Obtaining tumor-free margins is critical in initial and recurrence treatments.

Identifying critical quality metrics in Mohs Surgery: A national expert consensus process.

BACKGROUND: Amid a movement toward value-based healthcare, increasing emphasis has been placed on outcomes and cost of medical services. To define and demonstrate the quality of services provided by Mohs surgeons, it is important to identify and understand the key aspects of Mohs micrographic surgery (MMS) that contribute to excellence in patient care. OBJECTIVE: The purpose of this study is to develop and identify a comprehensive list of metrics in an initial effort to define excellence in MMS. METHODS: Mohs surgeons participated in a modified Delphi process to reach a consensus on a list of metrics. Patients were administered surveys to gather patient perspectives. RESULTS: Twenty-four of the original 66 metrics met final inclusion criteria. Broad support for the initiative was obtained through physician feedback. LIMITATIONS: Limitations of this study include attrition bias across survey rounds and participation at the consensus meeting. Furthermore, the list of metrics is based on expert consensus instead of quality evidence-based outcomes. CONCLUSION: With the goal of identifying metrics that demonstrate excellence in performance of MMS, this initial effort has shown that Mohs surgeons and patients have unique perspectives and can be engaged in a data-driven approach to help define excellence in the field of MMS.

The Controversy and Value of Mohs Micrographic Surgery for Melanoma and Melanoma in Situ on the Trunk and Extremities.

BACKGROUND: The use of Mohs surgery for melanoma on the trunk and extremities is not supported in the guidelines of dermatology, but is widely used in the real world. OBJECTIVE: The purpose of this article is to expose the value of Mohs surgery for melanoma on the trunk and extremities for consideration of updating the guidelines. MATERIALS AND METHODS: This was a retrospective review of a prospectively maintained database 7 to identify patients whose melanomas would likely have recurred using standard surgical margins. A prediction model was used to evaluate the value of Mohs surgery. RESULTS: The model predicted that 2,847 (2%) patients with melanoma on the trunk and extremities would likely recur each year with standard surgical margins even after re-excision when positive margins were identified, compared with 0.1% after Mohs surgery. This likely would result in the upstaging of 27% of melanoma in situ patients and 13% of patients with invasive melanoma. The upstaging would also result in a decrease in melanoma-specific survival and the death of 1% of patients with true local recurrences of melanoma. CONCLUSION: Mohs surgery has value for melanoma on the trunk and extremities by minimizing local recurrence and death from disease progression.

Outcomes of invasive melanoma of the head and neck treated with Mohs micrographic surgery - A multicenter study.

BACKGROUND: There are no randomized controlled trials to guide surgical margins for invasive head and neck (H&N) melanoma using conventional excision. Mohs micrographic surgery (MMS) has shown improved local recurrence rates and survival for invasive H&N melanomas. OBJECTIVE: Determine local recurrence (LR), nodal recurrence, and distant recurrence rates, and disease specific survival for invasive melanoma of the H&N treated with MMS. METHODS: A retrospective multicenter study of 785 cases of invasive H&N melanoma treated with MMS using frozen sections with melanoma antigen recognized by T-cells 1 immunohistochemical staining was performed to evaluate long-term outcomes over 12-years. RESULTS: 785 melanomas (thickness: 0.3 mm-8.5 mm) were treated with MMS. LR, nodal recurrence, and distant recurrence rates were 0.51% (4/785), 1.0% (8/785), and 1.1% (9/785) respectively. For T1, T2, T3, and T4 tumors LR was 0.16% (1/636), 1.18% (1/85), 2.22% (1/45), and 5.26% (1/19), respectively. Five and 10-year disease specific survival were 96.8% (95% CI 95.0% to 98.5%) and 93.4% (95% CI 88.5% to 98.3%). LIMITATIONS: A nonrandomized retrospective study. CONCLUSION: MMS achieves significant improvements in LR compared to a meta-analysis of historical cohorts of patients treated with conventional excision. MMS should be considered an important surgical option for invasive H&N melanoma.

Mohs Micrographic Surgery for Melanoma: Evidence, Controversy, and a Critical Review of Excisional Margin Guidelines.

Evidence supports the safety of Mohs micrographic surgery for melanoma. Because of its potential benefits to the patient in terms of very low-recurrence rates and same-day histologic confirmation of tumor removal with reconstruction of tumor-free margins of potentially smaller wounds, it should be one of the treatment options considered. The informed consent process for the patient should not be complete without a discussion of the attributes of Mohs surgery for melanoma.

Clinical outcomes of high-risk cutaneous squamous cell carcinomas treated with Mohs surgery alone: An analysis of local recurrence, regional nodal metastases, progression-free survival, and disease-specific death.

BACKGROUND: The incidence of cutaneous squamous cell carcinoma (cSCC) continues to increase, and it is now predicted that the number of deaths from cSCC will surpass that of melanoma within the next 5 years. Although most cSCCs are successfully treated, there exists an important subset of high-risk tumors that have the highest propensity for local recurrence (LR), nodal metastasis (NM), and disease-specific death (DSD). OBJECTIVE: We investigated the clinical outcomes of high-risk cSCCs treated with Mohs surgery (MS) alone, analyzing LR, NM, distant metastasis, and DSD. In addition, we analyzed progression-free survival and DSD in patients who underwent salvage head/neck dissection for regional NMs. METHODS: Retrospective review of all high-risk cSCC treated in our clinics between January 1, 2000, and January 1, 2020, with follow-up through April 1, 2020. SETTING: Two university-affiliated, private-practice MS referral centers. RESULTS: In total, 581 high-risk primary cSCCs were identified in 527 patients, of which follow-up data were obtained for 579 tumors. The 5-year disease-specific survival was 95.7%, with a mean survival time of 18.6 years. The 5-year LR-free survival was 96.9%, the regional NM-free survival was 93.8%, and the distant metastasis-free survival was 97.3%. The 5- and 10-year progression-free survival rates from metastatic disease were 92.6 and 90.0%, respectively. In patients who experienced regional NMs and underwent salvage head and neck dissection with or without radiation, the 2-year disease-specific survival was 90.5%. CONCLUSION: Our cohort, which is the largest high-risk cSCC cohort treated with MS to date, experienced lower rates of LR, NM, and DSD than those reported with historical reference controls using both the Brigham and Women's Hospital and American Joint Committee on Cancer, Eighth Edition, staging systems. We demonstrated that MS confers a disease-specific survival advantage over historical wide local excision for high-risk tumors. Moreover, by improving local tumor control, MS appears to reduce the frequency of regional metastatic disease and may confer a survival advantage even for patients who develop regional metastases.

Correlation of basal cell carcinoma subtype with histologically confirmed subclinical extension during Mohs micrographic surgery: A prospective multicenter study.

BACKGROUND: Traditionally "aggressive" histologic subtypes (HSs) of basal cell carcinoma (BCC) are more likely to quantitatively exhibit subclinical extension (SCE), requiring more stages during Mohs micrographic surgery (MMS) and, therefore, larger margins upon excision. However, the tendency for SCE has never been compared between HSs of BCC in a prospective manner. OBJECTIVE: To prospectively correlate the HS of BCC with the likelihood of SCE as defined by the number of MMS stages required to clear the tumor. METHODS: In a prospective, multicenter study involving 17 Mohs surgeons in 16 different practices across the United States, data regarding 1686 cases of BCC undergoing MMS were collected. Patient demographics, tumor characteristics, number of MMS stages required for tumor clearance, and specific BCC subtypes noted on both index biopsy and the final MMS stage were recorded. RESULTS: Analysis of the average number of MMS stages for each HS required to clear tumor revealed 2 distinct degrees of SCE (P < .0001): high (higher than average) risk of SCE (1.9 stages, 1.0 SD) and low (lower than average) risk of SCE (1.6 stages, 0.9 SD). Subtypes of BCC within the high category were morpheaform (2.1), infiltrative (1.9), metatypical (1.9), mixed (1.8), and superficial (1.8). The low category included BCC subtypes of basosquamous (1.6), micronodular (1.6), nodular (1.6), and unspecified (1.5). Three hundred twenty-four cases (22.0%) manifested HS drift or a change in subtype from index biopsy to the final MMS stage. Superficial BCC was the only subtype that showed an increase in prevalence from index biopsy to the final MMS stage (from 16.0% to 25.8%; P < .0002). LIMITATIONS: HSs from index biopsy may not be representative of all HSs present, resulting in sampling bias. CONCLUSION: SCE of superficial BCC was as likely as SCE of BCC subtypes that are considered "aggressive" and are deemed "appropriate" for MMS by the appropriate use criteria. Our study also found that when HS drift occurs, the most likely subtype to extend subclinically is superficial BCC.

Gene expression profiling for metastatic risk in head and neck cutaneous squamous cell carcinoma.

OBJECTIVE: Over 50% of newly diagnosed cutaneous squamous cell carcinoma (cSCC) lesions occur in the head and neck (cSCC-HN), and metastasis to nodal basins in this region further complicates surgical and adjuvant treatment. The current study addressed whether the 40-gene expression profile (40-GEP) test can predict metastatic risk in cSCC-HN with improved accuracy and provide independent prognostic value to complement current risk assessment methods. STUDY DESIGN: Multicenter, retrospective cohort study. METHODS: Formalin-fixed paraffin-embedded primary tumor tissue and associated clinical data from patients with cSCC-HN (n = 278) were collected from 33 independent centers. Samples were analyzed via the 40-GEP test. Cases were staged per American Joint Committee on Cancer, Eighth Edition (AJCC8) and Brigham and Women's Hospital (BWH) criteria after comprehensive medical record and pathology report review. Metastasis-free survival (MFS) rates were determined, and risk factors were analyzed via Cox regression. RESULTS: The 40-GEP test classified the cohort into low (Class 1, n = 126; 45.3%), moderate (Class 2A, n = 134; 48.2%), and high (Class 2B, n = 18; 6.5%) metastatic risk at 3 years postdiagnosis. Regional/distant metastasis occurred in 54 patients (19.4%). MFS rates were 92.1% (Class 1), 76.1% (Class 2A), and 44.4% (Class 2B; p < .0001). Multivariate analysis of 40-GEP results with AJCC8 or BWH tumor stage, or clinicopathologic risk factors, demonstrated independent prognostic value of the 40-GEP test (p < .03). Accuracy of predicting metastatic risk was also improved using 40-GEP classification (p < .02). CONCLUSIONS: Improved metastatic risk stratification through the 40-GEP test could complement cSCC-HN risk assessment for better-informed decision-making for treatment and surveillance and ultimately improve patient outcomes. LEVEL OF EVIDENCE: 3.

Enhanced metastatic risk assessment in cutaneous squamous cell carcinoma with the 40-gene expression profile test.

Aim: To clinically validate the 40-gene expression profile (40-GEP) test for cutaneous squamous cell carcinoma patients and evaluate coupling the test with individual clinicopathologic risk factor-based assessment methods. Patients & methods: In a 33-site study, primary tumors with known patient outcomes were assessed under clinical testing conditions (n = 420). The 40-GEP results were integrated with clinicopathologic risk factors. Kaplan-Meier and Cox regression analyses were performed for metastasis. Results: The 40-GEP test demonstrated significant prognostic value. Risk classification was improved via integration of 40-GEP results with clinicopathologic risk factor-based assessment, with metastasis rates near the general cutaneous squamous cell carcinoma population for class 1 and ≥50% for class 2B. Conclusion: Combining molecular profiling with clinicopathologic risk factor assessment enhances stratification of cutaneous squamous cell carcinoma patients and may inform decision-making for risk-appropriate management strategies.

Plain language summary Cutaneous squamous cell carcinoma is a common skin cancer, with approximately 2 million cases diagnosed each year in the USA. Because substantial numbers of patients experience metastasis, which can result in death, accurate metastatic risk assessment is important. Clinicians use clinicopathologic factors to determine risk for disease progression. However, traditional methods miss pinpointing many patients who experience metastasis and sometimes categorize patients as at risk who do not develop metastasis, indicating that additional tools are needed. A molecular test, the 40-gene expression profile (40-GEP), was developed to predict metastatic risk based on the biology of the tumor. This study demonstrates that the 40-GEP, either as an independent tool or together with traditional methods, accurately identifies patients' risk of metastasis. Using the 40-GEP could improve patient management to improve patient outcomes.

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.

Development and validation of a nomogram incorporating gene expression profiling and clinical factors for accurate prediction of metastasis in patients with cutaneous melanoma following Mohs micrographic surgery.

BACKGROUND: There is a need to improve prognostic accuracy for patients with cutaneous melanoma. A 31-gene expression profile (31-GEP) test uses the molecular biology of primary tumors to identify individual patient metastatic risk. OBJECTIVE: Develop a nomogram incorporating 31-GEP with relevant clinical factors to improve prognostic accuracy. METHODS: In an IRB-approved study, 1124 patients from 9 Mohs micrographic surgery centers were prospectively enrolled, treated with Mohs micrographic surgery, and underwent 31-GEP testing. Data from 684 of those patients with at least 1-year follow-up or a metastatic event were included in nomogram development to predict metastatic risk. RESULTS: Logistic regression modeling of 31-GEP results and T stage provided the simplest nomogram with the lowest Bayesian information criteria score. Validation in an archival cohort (n = 901) demonstrated a significant linear correlation between observed and nomogram-predicted risk of metastasis. The resulting nomogram more accurately predicts the risk for cutaneous melanoma metastasis than T stage or 31-GEP alone. LIMITATIONS: The patient population is representative of Mohs micrographic surgery centers. Sentinel lymph node biopsy was not performed for most patients and could not be used in the nomogram. CONCLUSIONS: Integration of 31-GEP and T stage can gain clinically useful prognostic information from data obtained noninvasively.

Mohs surgery for early-stage Merkel cell carcinoma (MCC) achieves local control better than wide local excision ± radiation therapy with no increase in MCC-specific death.

BACKGROUND: Merkel cell carcinoma (MCC) of the skin is most commonly treated with wide local excision (WLE) with or without adjuvant radiation therapy (RT). Mohs micrographic surgery (MMS) as monotherapy may offer an alternative treatment modality. The purpose of this study is to describe outcomes of patients with primary Stage I/II MCC treated with MMS alone and no RT. METHODS: A retrospectively collected sample of 56 MCCs treated with MMS was studied over an 18-year period. Tumor and treatment characteristics were described, and follow-up was assessed. RESULTS: A total of 56 primary Stage I/II MCCs in 53 patients were treated with MMS as monotherapy from April 2001 through July 2019. Patients were followed for an average of 4.6 years (median 2.7 years, range 0.8 to 16.9 years), of which 19 (33.9%) had follow-up of 5 years or more. There were no local recurrences due to inadequate excision. The 5-year Kaplan-Meier MCC-specific survival for AJCC8 Stage I and AJCC8 Stage IIA were 91.2% and 68.6%, respectively. CONCLUSION: In comparison to historical controls, Mohs surgery offers a survival that is at least as good as WLE +/- RT, with the added benefits of no need for adjuvant RT or the need for further surgery for treatment of local recurrence.