Retrospective cohort study of impact of postoperative radiotherapy on the prognosis of pT1-2N0M0 oral tongue squamous cell carcinoma

There is no consensus on the benefit of postoperative radiotherapy (PORT) in patients with early-stage (pT1-2N0M0) oral tongue squamous cell carcinoma (OTSCC). A retrospective cohort study at Zhejiang University (Hangzhou, China) found that among these patients, addition of PORT to surgery was associated with improved overall survival and disease-free survival in the subgroups with moderate-to-poor differentiation, perineural invasion, and lymphovascular invasion. The subgroup with depth of invasion > 5 mm had better disease-free survival but not overall survival with surgery plus PORT compared to surgery alone.