Is 3mm surgical margin safe in head and neck basal cell carcinoma smaller than 2cm; in relation to various risk factor.

Background Basal cell carcinoma(BCC) is the most common of non-melanoma skin cancer. Typically, resection requires a safety margin ≥ 4 mm. When removing tumor cells, achieving complete excision with minimal safety margins and reconstructing the defect to preserve the original appearance are important. In this study, we used a 3 mm resection margin to confirm recurrence and re-resection rates. Methods Electronic medical records and photographic data were obtained for patients with primary BCC lesions less than 2cm in diameter who underwent wide excision with a 3mm surgical margin from January 2015 to November 2021. We analyzed factors determining recurrence and re-resection rates, such as tumor size, location, age, sex, underlying diseases (including immunosuppression state), ethnicity, subtypes, tumor borders etc. Results This study included 205 patients. The mean age and follow-up period were 73.0 ± 11.5 years and 10.2 ± 8.0 months, respectively. The recurrence and re-resection rates were 1.95%, and 25.85%, respectively. A statistically significant correlation was found between recurrence rate and tumor border. (P = 0.013) And the re-resection rate was correlated statistically location (P = 0.022), and immunosuppressed patients. (P = 0.006) Conclusion We found that a 3 mm excision margin provided sufficient safety in small facial BCC, resulting in ease of surgery and better aesthetic outcomes. However, surgical margins must be determined case by case by integrating various patient factors. In particular, a surgical margin of ≥ 4 mm is required for BCC in high-risk areas or immunosuppressed patients or poorly-defined border.