In situ memory T cells and patterns of invasion predict outcome in patients with early-stage oral squamous cell carcinoma

Purpose The objective of this study was to explore the prognostic value of in situ memory T cells and patterns of invasion (POI) in early stage oral squamous cell carcinoma (OSCC). Methods One hundred fifty-seven patients with early stage (cT1T2N0) OSCC were identified from a pre-existing database of patients with oral cancer and were classified by POI according to hematoxylin-eosin staining. We examined the impact of the immunohistochemical expression of CD45RO in OSCC. Overall survival (OS) curves were calculated using the Kaplan-Meier method. Results Margin status was significantly associated with local recurrence in early stage OSCC (p= 0.000), and depth of invasion was also associated with regional recurrence (2 mm: p= 0.034; 4 mm: p= 0.015). The expression of CD45RO (p= 0.021) and POI (p= 0.027) individually was associated with OS, and patients in the group with combination score tended to have worse OS (p= 0.012). Conclusion Combined evaluation of POI and CD45RO might prove to be a useful indicator for high-risk patients with occult metastases from early stage OSCC.