International Session 48　　Larynx 4

Objectives : T2N0 laryngeal cancer has been recommended to be treated with radiotherapy(RT)as the standard treatment in clinical guidelines ; however, chemoradiotherapy(CRT)is often employed in clinical practice.The objective of this study was to investigate the difference in treatment efficacy and recurrence patterns between RT and CRT in patients with cT 2 laryngeal cancer.Patients and Methods : This multicenter, retrospective study spanning 13 hospitals in northern Japan (2014-2023)investigated treatment efficacy and recurrence patterns between radiotherapy(RT)and chemoradiotherapy (CRT)for cT2N0 laryngeal cancer.Results : We analyzed 377 patients treated with RT or CRT.RT patients were significantly older, with fewer supraglottic and more glottic tumors(p＜0． 05) .Recurrence sites/rates were similar.CRT improved RFS(86． 9％ vs. 74． 2％, p＜0． 05) , but local control rates were comparable(CRT : 89． 9％, RT : 82． 8％, p＝0． 19) .Conclusion : For cT2N0 laryngeal cancer, adding chemotherapy to RT improves RFS.Since LC was unchanged, this RFS gain likely results from reducing regional nodal recurrence and/or distant metastasis.