Retrospective Study Of Patterns Of Failure In Cutaneous Squamous Cell Carcinoma Treated With Primary Surgery: A Tata Medical Center Experience

Background: Cutaneous squamous cell carcinoma (cSCC) accounts for a significant proportion of skin malignancies in India, yet data on patterns of failure, particularly for extremity and truncal primaries remain scarce. We audited a decade of surgically treated cSCC at a tertiary cancer center to characterize failure patterns and associated risk factors. Methods: This retrospective study included 161 patients with histopathologically confirmed cSCC treated surgically between January 2013 and December 2023, comprising 127 upfront/residual and 34 recurrent presentations. Primary sites were extremities (64%), head and neck (26%) and torso (10%). 21 patients had Marjolin's ulcer. Outcomes included local, regional and distant failure, recurrence-free survival and overall survival. Brigham and Women's Hospital (BWH) staging was applied to assess prognostic utility. Statistical analysis was done using Kaplan-Meier and competing-risk methods. Results: Median follow-up was 2.4 years. Regional recurrence was the predominant failure pattern seen in 26 patients, local recurrence was seen in 14 patients and distant metastasis in 13. The 3-year cumulative incidences of local, regional and distant failure were 11%, 19% and 8.4% respectively. Rates of regional recurrence were substantially higher than Western series. Extremity primaries accounted for 19/26 regional recurrences. BWH T2b disease showed the highest regional failure rate (27.6%), exceeding T3 (17.8%) and T2a (6%) with perineural invasion significantly associated with regional failure in T2b/T3 tumors (p<0.001). Median time to regional metastasis was 8.4 months. At 3 years, overall survival was 77% and progression-free survival was 64%. Conclusion: Regional recurrence is the dominant mode of failure in this cohort, at rates higher than most published series, with extremity primaries and BWH T2b staging identifying particularly high-risk subgroups. These findings highlight the need for a comprehensive staging system encompassing non head and neck cSCC and support prospective evaluation of elective nodal staging and adjuvant radiotherapy in high-risk patients, alongside intensified surveillance.