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.

Flight system morphology and minimum flight temperature in North American cicadas (Insecta: Hemiptera: Cicadidae).

Thermal responses in cicadas have been studied for many years. The minimum flight temperature (MFT) does not show the same relationship to habitat and behavior as other thermal responses. We measured live mass, wing length, wingspan, wing area and wing loading in an attempt to correlate these morphological parameters to the MFT. We analyzed both intraspecific (in Magicicada cassinii (Fisher, 1852)) and interspecific relationships of the wing morphology and the ability of the cicadas to fly in a large number of North American cicada taxa (n=119). A total of 109 species and 10 subspecies from 17 genera, six tribes, and three subfamilies including all major North American habitats were studied. Analyses show that wing morphology (wing length, wingspan, wing area and wing loading) scales to body size as predicted by geometric similarity (all P<0.0001) for all species and wing area and wing loading (both P<0.0001) in M. cassinii. Mass (P=0.0105), wing length (P=0.0006), wingspan (P=0.0006), wing area (P=0.0055), and wing loading (P=0.0455) all demonstrate a significant correlation to MFT between species, as would be predicted by aerodynamic theory, but not within species. However, the low correlation coefficients suggest the flight system has minimal influence on the MFT of cicadas. Specific physiological adaptations appear to be responsible for the between species variability in MFT rather than being the result of modifications to the flight system morphology.

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.

State of the art of Mohs surgery for rare cutaneous tumors in the Spanish Registry of Mohs Surgery (REGESMOHS).

BACKGROUND: The use of Mohs micrographic surgery (MMS) for rare cutaneous tumors is poorly defined. We aim to describe the demographics, tumor presentation and topography, surgery characteristics and complications of MMS for rare cutaneous tumors in a national registry. METHODS: Prospective cohort study of patients treated with MMS in Spain between July 2013 and June 2018. The inclusion criteria were patients with cutaneous tumors with final diagnosis different from basal cell carcinoma, squamous cell carcinoma, dermatofibrosarcoma protuberans, or any kind of melanoma. RESULTS: Five thousand and ninety patients were recorded in the registry, from which only 73 tumors (1.4%) fulfilled the inclusion criteria: atypical fibroxanthoma (18), microcystic adnexal carcinoma (10), extramammary Paget's disease (7), Merkel cell carcinoma (5), dermatofibroma (4), trichilemmal carcinoma (4), desmoplastic trichoepithelioma (4), sebaceous carcinoma (3), leiomyosarcoma (2), porocarcinoma (2), angiosarcoma (2), trichoblastoma (1), superficial acral fibromyxoma (1), and others (10). No intra-surgery morbidity was registered. Postsurgery complications appeared in six patients (9%) and were considered mild. Median follow-up time was 0.9 years during which three Merkel cell carcinomas, one angiosarcoma, one microcystic adnexal carcinoma, and four others recurred (12.3%). CONCLUSION: This national registry shows that rare cutaneous tumors represent a negligible part of the total MMS performed in our country with a low complication rate.