Risk of a Second Skin Cancer in a Cohort of Patients With Nonmelanoma Skin Cancer -Basal Cell Carcinoma or Squamous Cell Carcinoma-Treated With Mohs Micrographic Surgery: A National Prospective Cohort Study. / Riesgo de aparición de segundas neoplasias cutáneas en una cohorte de pacientes diagnosticados de carcinoma queratinocítico (carcinoma basocelular y carcinoma epidermoide) tratados con cirugía de Mohs. Estudio de cohortes prospectivo nacional.

OBJECTIVE: Patients with nonmelanoma skin cancer (NMSC)-ie, basal cell carcinoma (BCC) or squamous cell carcinoma (SCC)-have an increased risk of developing a second skin cancer. The aim of this study was to describe the frequency, incidence per 1000 person-years, and predictors of a second skin cancer in a cohort of patients with NMSC treated with Mohs micrographic surgery (MMS). MATERIAL AND METHODS: Prospective study of a national cohort of patients with NMSC who underwent MMS at 22 Spanish hospitals between July 2013 and February 2020; case data were recorded in the REGESMOHS registry. The study variables included demographic characteristics, frequency and incidence per 1000 person-years of second skin cancers diagnosed during the study period, and risk factors identified using mixed-effects logistic regression. RESULTS: We analyzed data for 4768 patients who underwent MMS; 4397 (92%) had BCC and 371 (8%) had SCC. Mean follow-up was 2.4 years. Overall, 1201 patients (25%) developed a second skin cancer during follow-up; 1013 of the tumors were BCCs (21%), 154 were SCCs (3%), and 20 were melanomas (0.4%). The incidence was 107 per 1000 person-years (95% CI, 101-113) for any cancer, 90 per 1000 person-years (95% CI, 85-96) for BCC, 14 (95% CI, 12-16) per 1000 person-years for SCC, and 2 (95% CI, 1-3) per 1000 person-years for melanoma. More men than women developed a subsequent skin cancer (738 [61%] vs 463 [39%]). The main risk factors were a history of multiple tumors before diagnosis (relative risk [RR], 4.6; 95% CI, 2.9-7.1), immunosuppression (RR, 2.1; 95% CI, 1.4-3.1), and male sex (RR, 1.6; 95% CI, 1.4-1.9). CONCLUSION: Patients have an increased risk of developing a second tumor after MMS treatment of NMSC. Risk factors are a history of multiple tumors at diagnosis, immunosuppression, and male sex.

Mohs micrographic surgery in the elderly: comparison of tumours, surgery and first-year follow-up in patients younger and older than 80 years old in REGESMOHS.

BACKGROUND: The elderly population is increasing and more patients in this group undergo Mohs micrographic surgery (MMS). The few publications investigating MMS in elderly people conclude that it is a safe procedure; however, these are single-centre studies without a comparison group. OBJECTIVE: To compare the characteristics of patients, tumours, MMS and 1-year follow-up in patients younger than 80 years, with patients older than 80 years at the time of surgery. METHODS: Data was analysed from REGESMOHS, a prospective cohort study of patients treated with MMS. The participating centres were 19 Spanish hospitals where at least one MMS is performed per week. Data on characteristics of the patient, tumour and surgery were recorded. Follow-up data were collected from two visits; the first within 1 month postsurgery and the second within the first year. RESULTS: From July 2013 to October 2016, 2575 patients that underwent MMS were included in the registry. Of them, 1942 (75.4%) were aged <80 years and 633 (24.6%) were ≥80 years old. In the elderly, the tumour size was significantly higher with a higher proportion of squamous cell carcinoma. Regarding surgery, elderly more commonly had tumours with deeper invasion and required a higher number of Mohs surgery stages, leaving larger defects and requiring more time in the operating room. Despite this, the incidence of postoperative complications was the same in both groups (7%) and there were no significant differences in proportion of relapses in the first-year follow-up. CONCLUSION: The risk of short-term complications and relapses were similar in elderly and younger groups. MMS is a safe procedure in the elderly.

Characterization of Surgical Procedures in the Spanish Mohs Surgery Registry (REGESMOHS) for 2013-2015. / Descripción de las intervenciones quirúrgicas recogidas en el registro español de cirugía de Mohs (REGESMOHS) (2013-2015).

INTRODUCTION: The Spanish Mohs Surgery Registry is used to collect data on the use and outcomes of Mohs micrographic surgery (MMS) in Spain. The aim of this study was to describe perioperative and intraoperative data recorded for MMS procedures performed between July 2013 (when the registry started) and January 2016. MATERIAL AND METHODS: Prospective cohort study of data from 18 hospitals. The data collected included type of anesthesia, surgical technique, hospital admission, number of Mohs stages, management of preoperative risk factors, additional treatments, previous treatments, type of tumor, operating time, and complications. RESULTS: Data were available for 1796 operations. The most common tumor treated by MMS was basal cell carcinoma (85.96%), followed by squamous cell carcinoma (6.18%), lentigo maligna (2.81%), and dermatofibrosarcoma protuberans (1.97%). Primary tumors accounted for 66.9% of all tumors operated on; 19.2% of tumors were recurrent and 13.9% were persistent. The most common previous treatment was surgical. MMS was mostly performed under local anesthesia (86.7% of cases) and as an outpatient procedure (71.8%). The frozen section technique was used in 89.5% of cases. One stage was needed to achieve tumor-free margins in 56.45% of patients; 2 stages were required in 32.1% of patients, 3 in 7.1%%, 4 in 2.7%, and 5 or more in 1.8%. The defect was reconstructed by the dermatologist in 98% of patients and the most common technique was flap closure (47.2%). Intraoperative complications were recorded for just 1.62% of patients and the median (interquartile range) duration of surgery was 75 (60-100) minutes. CONCLUSION: The characteristics of the patients and tumors treated by MMS are similar to those reported for similar studies in other geographic areas. Lentigo maligna and dermatofibrosarcoma protuberans accounted for a higher proportion of cases in our series, and repair of the surgical defect by a dermatologist was also more common. Operating times in MMS are not much longer than those reported for other procedures and the rate of intraoperative complications is very low.