Mohs micrographic surgery in immunosuppressed vs immunocompetent patients: Results of a prospective nationwide cohort study (REGESMOHS, Spanish registry of Mohs surgery).

BACKGROUND: Immunosuppressed (IS) patients, particularly solid organ transplant recipients and those on immunosuppressive therapy, face a higher incidence and recurrence of nonmelanoma skin cancers (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Mohs micrographic surgery (MMS) is the preferred treatment for high-risk NMSC due to its high cure rate and margin examination capabilities. However, IS patients may experience more complications, such as surgical site infections, and a greater risk of recurrence, making their outcomes a subject of interest. OBJECTIVES: This study aimed to compare IS and immunocompetent (IC) patients undergoing MMS for NMSC in terms of baseline characteristics, intra- and post-surgical complications, and postoperative recurrence rates. METHODS: The study utilized data from the REGESMOHS registry, a 7-year prospective cohort study in Spain. It included 5226 patients, categorizing them into IC (5069) and IS (157) groups. IS patients included solid organ transplant recipients, those on immunosuppressive treatments, individuals with haematological tumours and HIV-positive patients. Patient data, tumour characteristics, surgical details and outcomes were collected and analysed. RESULTS: IS patients demonstrated a higher proportion of SCC, multiple synchronous tumours and tumours invading deeper structures. Complex closures, unfinished MMS and more surgical sections were observed in the IS group. Although intra-operative morbidity was higher among IS patients, this difference became non-significant when adjusted for other variables such as year of surgery, antiplatelet/anticoagulant treatment or type of closure. Importantly, IS patients had a substantially higher recurrence rate (IRR 2.79) compared to IC patients. CONCLUSIONS: This study suggests that IS patients may be at a higher risk of development of AE such as bleeding or tumour necrosis and are at a higher risk of tumour recurrence. Close follow-up and consideration of the specific characteristics of NMSC in IS patients are crucial. Further research with extended follow-up is needed to better understand the long-term outcomes for this patient group.

Development and validation of a model to predict complex Mohs micrographic surgery in clinical practice: REGESMOSH scale.

INTRODUCTION: There is still a need to develop a simple algorithm to identify patients likely to need complex Mohs micrographic surgery (MMS) and optimize MMS schedule. The main objectives of this study are to identify factors associated with a complex MMS and develop a predictor model of the number of stages needed in surgery and the need for a complex closure. MATERIALS AND METHODS: A nationwide prospective cohort study (REGESMOHS, the Spanish Mohs surgery registry) was conducted including all patients with a histological diagnosis of basal cell carcinoma (BCC). Factors related to three or more stages and a complex closure (that needing a flap and/or a graft) were explored and predictive models were constructed and validated to construct the REGESMOSH scale. RESULTS: A total of 5226 patients that underwent MMS were included in the REGESMOHS registry, with 4402 (84%) having a histological diagnosis of BCC. A total of 3689 (88.9%) surgeries only needed one or two stages and 460 (11.1%) required three or more stages. A model to predict the need for three or more stages included tumour dimension, immunosuppression, recurrence, location in risk areas, histological aggressiveness and previous surgery. Regarding the closure type, 1616 (38.8%) surgeries were closed using a non-complex closure technique and 2552 (61.2%) needed a complex closure. A model to predict the need for a complex closure included histological aggressiveness, evolution time, patient age, maximum tumour dimension and location. CONCLUSION: We present a model to predict MMS needing ≥3 stages and a complex closure based on epidemiological and clinical data validated in a large population (with real practice variability) including different centres that could be easily implemented in clinical practice. This model could be used to optimize surgery schedule and properly inform patients about the surgery duration.

Risk Factors and Rate of Recurrence after Mohs Surgery in Basal Cell and Squamous Cell Carcinomas: A Nationwide Prospective Cohort (REGESMOHS, Spanish Registry of Mohs Surgery).

Randomized studies to assess the efficacy of Mohs micrographic surgery in basal cell and squamous cell carcinomas are limited by methodological and ethical issues and a lack of long follow-up periods. This study presents the "real-life" results of a nationwide 7-years cohort on basal cell carcinoma and squamous cell carcinoma treated with Mohs micrographic surgery. A prospective cohort was conducted in 22 Spanish centres (from July 2013 to February 2020) and a multivariate analysis, including characteristics of patients, tumours, surgeries and follow-up, was performed. A total of 4,402 patients followed up for 12,111 patient-years for basal cell carcinoma, and 371 patients with 915 patient-years of follow-up for squamous cell carcinoma were recruited. Risk factors for recurrence included age, non-primary tumours and more stages or unfinished surgeries for both tumours, and immunosuppression for squamous cell carcinoma. Incidence rates of recurrence were 1.3 per 100 person-years for basal cell carcinoma (95% confidence interval 1.1-1.5) and 4.5 for squamous cell carcinoma (95% confidence interval 3.3-6.1), being constant over time (0-5 years). In conclusion, follow-up strategies should be equally intense for at least the first 5 years, with special attention paid to squamous cell carcinoma (especially in immunosuppressed patients), elderly patients, non-primary tumours, and those procedures requiring more stages, or unfinished surgeries.

Mohs micrographic surgery in dermatofibrosarcoma protuberans: Rate and risk factors for recurrence in a prospective cohort study from the Spanish Registry of Mohs Surgery (REGESMOHS) and review of the literature.

Characterization of patients, surgery procedures and the risk factors for dermatofibrosarcoma protuberans (DFSP) recurrences is poorly defined. In this study, we aimed to describe the demographics, tumor characteristics and interventions of DFSP treated with Mohs micrographic surgery (MSS) to determine the rate and risk factors for recurrence. Data were collected from REGESMOHS, a nationwide prospective cohort study of patients treated with MMS in Spain. From July 2013 to February 2020, 163 patients with DFSP who underwent MMS were included. DFSP was mostly located on trunk and extremities. Recurrent tumors had deeper tumor invasion and required higher number of MMS stages. Paraffin MMS was the most frequently used technique. Overall recurrence rate was 0.97 cases/100 person-years (95% IC = 0.36-2.57). No differences were found in epidemiological, tumor, surgery characteristics or surgical technique (frozen or paraffin MMS [p = 0.6641]) in terms of recurrence. Median follow-up time was 28.6 months with 414 patient-years of follow-up. In conclusion, we found an overall low recurrence rate of DFSP treated with MMS. None of the studied risk factors, including MMS techniques, was associated with higher risk for recurrence.