https://www.selleckchem.com/products/ABT-888.html To analyze the clinical characteristics and long-term follow-up of patients with advanced ocular surface squamous cell carcinoma (OSSC) involving periocular tissues and/or orbit. Primary outcomes were overall survival (OS), disease-free survival (DFS), and overall recurrence rate (RR). Secondary outcomes were a correlation between primary outcomes and tumor location, American Joint Committee on Cancer Classification (AJCC) staging system, histological results, surgical margins, and type of treatment. a retrospective case series. The medical records of patients affected by OSSC involving periocular tissues and/or orbit referring, from 01/2011 to 01/2020, toour tertiary referral center were reviewed. Thirty-six eyes of 36 patients were included. The mean age was 68.2years; 18 (50%) patients were males. The mean follow-up was 40months. The RR was 64%. The OS at 12, 24, 36, and 60months was respectively 97.1%, 92.7%, 92.7%, and 92.7%. The DFS at 12, 24, 36, and 60months was respectively 62.9%, 50.8%, 41.6%, and 29.7%. Multicentric disease (p = 0.0039), inferior tarsus localization (p = 0.0428), histological diagnosis of high-risk SSCs (p = 0.0264), positive surgical margins (p = 0.0434), and excisional biopsy (EB) alone (p = 0.0005) were associated with an increased risk of recurrence. A shorter OS was observed in patients who underwent EB alone (p = 0.0049). OSCC involving periocular tissues and/or orbit is an aggressive disease with a high recurrence rate. Multicentric disease, positive surgical margins, inferior tarsus localization, and surgery without adjuvant therapies are strong predictors of recurrence and are the main factors affecting prognosis. OSCC involving periocular tissues and/or orbit is an aggressive disease with a high recurrence rate. Multicentric disease, positive surgical margins, inferior tarsus localization, and surgery without adjuvant therapies are strong predictors of recurrence and are the main