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.

MATERIAL 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 3 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

5226 patients that underwent MMS were included in the REGESMOHS registry, with 4402 (84%) having a histological diagnosis of BCC. 3689 (88.9%) surgeries only needed one or two stages and 460 (11.1%) required 3 or more stages. A model to predict the need for 3 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 patientyears 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.

Complications Associated with Mohs Micrographic Surgery: Data from the Nationwide Prospective Cohort REGESMOHS

BACKGROUND

Large prospective studies on the safety of Mohs micrographic (MMS) surgery are scarce, and most focus on a single type of surgical adverse event. Mid-term scar alterations and functional loss have not been described.

OBJECTIVES

To describe the risk of MMS complications and the risk factors for them.

METHODS

A nationwide prospective cohort collected all adverse events on consecutive patients in 22 specialised centres. We used multilevel mixed-effects logistic regression to find out factors associated with adverse events.

RESULTS

5,017 patients were included, with 14,421 patient-years of follow-up. 7.0% had some perioperative morbidity and 6.5% had mid-term and scar-related complications. The overall risk of complications was mainly associated with use of antiaggregant/anticoagulant and larger tumours, affecting deeper structures, not reaching a tumour-free border, and requiring complex repair. Age and outpatient setting were not linked to the incidence of adverse events. Risk factors for haemorrhage (0.9%) were therapy with antiaggregant/anticoagulants, tumour size, duration of surgery, and unfinished surgery. Wound necrosis (1.9%) and dehiscence (1.0%) were associated with larger defects and complex closures. Immunosuppression was only associated with an increased risk of necrosis. Surgeries reaching deeper structures, larger tumours and previous surgical treatments were associated with wound infection (0.9%). Aesthetic scar alterations (5.4%) were more common in younger patients, with larger tumours, in H-area, and in flap and complex closures. Risk factors for functional scar alterations (1.7%) were the need for general anaesthesia, larger tumours that had received previous surgery, and flaps or complex closures.

CONCLUSIONS

MMS shows a low risk of complications. Most of the risk factors for complications were related to tumour size and depth, and the resulting need for complex surgery. Antiaggregant/anticoagulant intake was associated with a small increase in the risk of haemorrhage, that probably does not justify withdrawal. Age and outpatient setting were not linked to the risk of adverse events.

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.

Description of Patients Undergoing Mohs Surgery in Spain: Initial Report on Data From the Spanish Registry of Mohs Surgery (REGESMOHS)

INTRODUCTION

The Spanish registry of Mohs micrographic surgery started collecting data in July 2013. The aim of the registry is to report on the use of this technique in Spain and the outcomes achieved. In the present article, we describe the characteristics of patients and the tumors treated.

MATERIAL AND METHODS

This is a prospective cohort study of patients treated with Mohs micrographic surgery. The participating centers are hospitals where at least one intervention of this type is performed each week. All patients considered for Mohs micrographic surgery in participating centers are included in the registry except those who have been declared legally incompetent.

RESULTS

Between July 2013 and October 2014, data from 655 patients were included in the registry. The most common tumor involved was basal cell carcinoma, and the most common histological subtype was infiltrative basal cell carcinoma. Most of the tumors treated were located on the face or scalp, and the most common site was the nose. Almost 40% of the tumors treated were recurrent or persistent, and preoperative tumor size was similar to that reported in other European studies and in Australia. In total, 45.5% of patients had received previous surgical treatment.

CONCLUSION

The findings are similar to those reported in other studies, and the data collected are useful for assessing whether the results of studies carried out elsewhere are applicable in Spain.