# Targeting Anterior Commissure Involvement with Hyperfractionated Radiotherapy for T1–T2 Squamous Cell Carcinoma of the Glottic Larynx

## TL;DR

This study shows that hyperfractionated radiotherapy effectively treats early-stage larynx cancer involving the anterior commissure, especially for T1 tumors, with high survival and larynx preservation rates.

## Contribution

The study evaluates hyperfractionated radiotherapy as a treatment strategy for anterior commissure involvement in early-stage glottic cancer.

## Key findings

- The 10-year overall survival rate was 72% and cause-specific survival was 97%.
- Local control rates were 94% for T1a, 88% for T1b, and 81% for T2 disease.
- Laryngeal preservation rate was 96% with minimal severe side effects.

## Abstract

Anterior commissure involvement (ACI) is an important factor in the local control of early-stage glottic squamous cell carcinoma (EGSCC). We initiated a radiotherapeutic treatment regimen focusing on ACI, which has included hyperfractionated radiotherapy since 2008. One-hundred and fifty-three patients with T1–T2 EGSCC were included in this study. Hyperfractionated radiotherapy (74.4 Gy in 62 fractions) was used for EGSCC with ACI. The 10-year overall survival and cause-specific survival rates were 72% and 97%, respectively. The 10-year local control rates were 94% for T1a, 88% for T1b, and 81% for T2 disease. Local control rates in patients with ACI were slightly better than those in patients without ACI with T1a and T1b diseases; however, the difference was not significant. The 10-year laryngeal preservation rate was 96%. In conclusion, hyperfractionated radiotherapy was effective for T1 disease with ACI but insufficient for T2 disease with ACI. Our treatment strategy resulted in excellent laryngeal preservation.

Anterior commissure is involved in about 20% of early-stage glottic squamous cell carcinomas (EGSCCs). Treatment outcomes and prognostic factors for EGSCC with anterior commissure involvement (ACI) were evaluated by focusing on hyperfractionated radiotherapy (74.4 Gy in 62 fractions). One-hundred and fifty-three patients with T1–T2 EGSCC were included in this study. The median total doses for T1a, T1b, and T2 were 66, 74.4, and 74.4 Gy, respectively. Overall, 49 (32%) patients had T1a, 38 (25%) had T1b, and 66 (43%) had T2 disease. The median treatment duration was 46 days. The median follow-up duration was 5.1 years. The 10-year overall and cause-specific survival rates were 72% and 97%, respectively. The 10-year local control rates were 94% for T1a, 88% for T1b, and 81% for T2 disease. Local control rates in patients with ACI were slightly better than those in patients without ACI with T1a and T1b diseases; however, the difference was not significant. The 10-year laryngeal preservation rate was 96%. Six patients experienced grade 3 mucositis, and four patients had grade 3 dermatitis. Hyperfractionated radiotherapy was effective for T1 disease with ACI, but insufficient for T2 disease with ACI. Our treatment strategy resulted in excellent laryngeal preservation.