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.