Human papillomavirus (HPV) infection detected in oropharyngeal squamous cell carcinoma (OPSCC) is associated with a better survival outcome from previous literature. However, Thailand and several Asian countries have a low prevalence of HPV-associated OPSCC and, therefore, have a low positive rate of immunostaining with p16. Tumor microenvironments (TME), including tumor-infiltrating CD8+ lymphocytes (CD8+ TIL) and programmed death ligand 1 (PD-L1), are proposed as significant prognostic indicators in addition to p16. Objectives: Explore the expression p16, CD8+ TIL, and PD-L1 and its value as prognostic indicators for overall survival (OS) in patients with OPSCC. Materials and Methods: Data from patients with OPSCC diagnosed from 2012 to 2018 were recovered from medical records and national registry. All available glass slides and slides of immunohistochemistry (IHC) of p16, CD8, and PD-L1 were reviewed. The TME was classified into four types according to the expression pattern of PD-L1 and CD8+TIL. Overall survival (OS) was assessed using the Kaplan–Meier method and Cox regression model analysis. Results: In 160 OPSCC patients, p16 was positive in 27 (16.88%). The density of CD8+ TIL was higher in the p16+ and PD-L1+ groups (p = 0.005, 0.039); however, there was no association between p16 and the status of PD-L1. P16 and CD8+ TIL were significant prognostic factors for better OS (p = 0.007, 0.001), but not PD-L1 status (p = 0.317). Among the four types of TME, carcinoma showed mainly type IV TME (PD-L1−/TIL+), while OPSCCs with type I TME (PD-L1+/TIL+) had the best survival outcome. Conclusions: The positivity of p16 and the density of CD8+ TIL were associated with better OS in OPSCC, while the status of PD-L1 was not significantly related to OS. OPSCC with type I TME (PD-L1+/TIL+) showed the best prognosis of all types of TME.

Background. Phyllodes tumors (PTs) are fibroepithelial neoplasms of the breast, with current treatment guidelines recommending wide excision to achieve surgical margins of ≥1 cm to minimize the recurrence risk. However, diagnostic challenges with core biopsy specimens often result in suboptimal surgical margins. This study aims to elucidate the correlation between margin status and PT recurrence, thereby informing surgical decision‐making and enhancing patient outcomes. Methods. This single‐center, retrospective study reviewed records of Thai women diagnosed with PTs between 2011 and 2018, collecting data on demographics, clinical presentation, surgical approach, tumor grade, size, and margin status. The primary endpoint was recurrence. Results. Among 165 PT cases analyzed—49.1% borderline, 38.2% benign, and 12.7% malignant—the overall recurrence rate was 13.9% (n = 23) over a median follow‐up of 4.5 years. No significant difference in recurrence rates was observed between patients with negative resection margins <1 cm (ranging from <1 mm to 9 mm) compared to those with ≥1 cm (10.2% vs. 7.1%, p = 1.00). Notably, in negative resection margins <1 cm group, a margin <1 mm (close margin) was associated with a significantly higher recurrence rate compared to margins of 1–9 mm (17.0% vs. 4.9%, p = 0.04). Borderline PTs followed the overall trend, while benign PTs showed increased recurrence with positive margins. Multivariate analysis indicated a significant association between margins <1 mm and recurrence (adjusted HR = 10.78 (95% CI 1.32–88.07), p = 0.027), highlighting an increased recurrence risk with more extensive positive margins. Conclusion. Our findings suggest that a wide surgical margin of ≥1 centimeter may not be necessary to prevent recurrence in benign and borderline PTs. Notably, surgical margins narrower than 1 millimeter substantially elevate the recurrence likelihood in cases of borderline PTs. Furthermore, the presence of positive surgical margins correlates with an increased recurrence rate in benign PTs. These findings highlight the critical need for a strategic approach in determining surgical margins, tailored specifically to the type of PT, to enhance patient outcomes effectively.