The Application of Adjuvant Radiotherapy in pN1 OSCC Patients Without Adverse Pathologic Features.

Purpose: This study aimed to assess the necessity of adjuvant radiotherapy for oral squamous cell carcinoma patients with a pN1 stage and no adverse pathological features.

Patients and methods: This was a multicenter cohort study including 231 patients.

Results: Among the enrolled patients, 171 received adjuvant radiotherapy, and 60 did not. According to the Kaplan-Meier survival analysis, there were no significant differences between the two groups in terms of disease-free survival (59.5% vs. 58.3%, p = 0.938), overall survival (73.1% vs. 75.0%, p = 0.936), and disease-specific survival (74.9% vs. 76.7%, p = 0.914). In patients with local/regional recurrence after surgery, after-recurrence survival (34.8% vs. 44.0%, p = 0.197) was not significantly different. Analysis by T stage revealed no significant differences in disease-free survival (60.9% vs. 75.0%, p = 0.084), overall survival (73.6% vs. 90.6%, p = 0.053) and disease-specific survival (75.8% vs. 90.6%, p = 0.072) for T1-2 patients between the radiotherapy and non-radiotherapy groups. The results revealed statistically significant differences in disease-free survival (57.9% vs. 39.3%, p = 0.030), overall survival (72.4% vs. 57.1%, p = 0.034) and disease-specific survival (73.7% vs. 60.7%, p = 0.049) between the two groups.

Conclusions: Adjuvant radiotherapy does not improve the prognosis of T1-2N1M0 patients without adverse pathological features; however, adjuvant radiotherapy should be recommended for T3-4aN1M0 patients.