# Impact of postoperative radiotherapy and chemoradiotherapy on survival outcomes in oral squamous cell carcinoma patients with pN1 neck disease

## TL;DR

This study finds that postoperative radiotherapy improves survival and reduces recurrence in oral cancer patients with pN1 neck disease, while adding chemotherapy does not provide significant benefits.

## Contribution

The study provides evidence supporting postoperative radiotherapy as the preferred adjuvant treatment for oral squamous cell carcinoma patients with pN1 neck disease.

## Key findings

- Postoperative radiotherapy significantly reduces recurrence risk and improves recurrence-free survival in OSCC patients with pN1 neck disease.
- Postoperative radiotherapy is associated with improved 5-year overall survival compared to surgery alone.
- Postoperative chemoradiotherapy does not offer additional survival benefits over postoperative radiotherapy alone.

## Abstract

The lymph node management of oral squamous cell carcinoma (OSCC) patients with pN1 neck remains a clinical challenge. This study investigates the impact of different treatment modalities – surgery alone, surgery with postoperative radiotherapy (PORT), and surgery with postoperative chemoradiotherapy (PCRT) – on recurrence and survival outcomes in OSCC patients with pN1 neck.

A retrospective cohort study was conducted on 98 patients who underwent tumor resection and neck dissection, with a subset receiving adjuvant therapy, between 2011 and 2020. Clinicopathological characteristics were examined for associations with treatment modality using chi-square test. Kaplan-Meier survival curves for overall survival (OS) and recurrence-free survival (RFS), along with the log-rank test, were employed to assess survival over a 10-year period. The prognostic significance of clinicopathological factors and treatment modalities was evaluated using Cox proportional hazards models.

The addition of PORT following surgery significantly reduced the risk of recurrence (HR = 0.280, p = 0.010) and enhanced RFS, particularly at 10 years (p = 0.010). PORT was also associated with a statistically significant improvement in 5-year-OS (p = 0.031) compared to surgery alone, with a trend toward improved OS at 10 years (p = 0.175). In contrast, surgery alone did not yield comparable 10-year survival outcomes. Additionally, the inclusion of PCRT did not show a distinct survival advantage over the combination of surgery and PORT.

Our results indicate that PORT may be considered the standard adjuvant treatment for these patients, as it improves RFS, particularly in the long term, while the addition of chemotherapy does not provide significant additional benefits over PORT alone.