Long-term results of the phase II dose and volume de-escalation trial for locoregionally advanced nasopharyngeal carcinoma. (November 2022)

• Record Type: Journal Article
• Authors: Xue, Fen; Ou, Dan; Ou, Xiaomin; Zhou, Xin; Hu, Chaosu; He, Xiayun
• Is Part Of: Oral oncology. Volume 134(2022)
• Publication Date: 2022-11
• Subjects: Nasopharyngeal carcinoma -- Treatment de-escalation -- Induction chemotherapy -- Intensity-modulated radiation therapy; Mouth -- Cancer -- Periodicals; Mouth -- Tumors -- Periodicals; Mouth Diseases -- Periodicals; Mouth Neoplasms -- Periodicals; Bouche -- Cancer -- Périodiques; Bouche -- Tumeurs -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9943105
• DOI: 10.1016/j.oraloncology.2022.106139
• Languages: English
• ISSNs: 1368-8375

Abstract

Highlights: The role of IC in tumor shrinkage was beneficial for radiotherapy planning. Dose and volume de-escalation radiotherapy according to IC was feasible. Long-term results of the de-escalation trial for LANPC were satisfactory. Abstract: Objective: Patients with locoregionally advanced nasopharyngeal carcinoma (LANPC) were assigned to dose and volume de-escalated intensity-modulated radiation therapy (IMRT) based on response to induction chemotherapy (IC) to limit treatment related toxicity while preserving efficacy. Methods and materials: A single-arm de-escalated phase II trial was performed in this study. Patients with LANPC received two cycles of IC with docetaxel 60 mg/m 2 d1, cisplatin 25 mg/m 2 /day d1-3 and 5-fluorouracil 500 mg/m 2 /day d1-5 q21d, followed by IMRT. The gross tumor volume of the primary intracavity nasopharyngeal tumor and involved lymph nodes were delineated based on the post-IC tumor extension. Part of the prescribed doses were reduced from 70.4 Gy to 66 Gy for T3-4 diseases. The primary end point was 5-year progression-free survival (PFS) in stage III and IVA-B NPC compared with historical controls of 50% and 35%. Results: Between January 2010 and November 2013, 48 and 83 eligible patients with stage III and IVA-B NPC were accrued to this trial. With a median follow-up of 92 months, the 5-year and 8-year estimated PFS were 89.6% and 76.0%, 63.9% and 58.0% for patients with stage III and IVA-B disease, which were all improved in comparison with historical controls. Grade 3 acute mucositis were developed in 27.5% patients. Cranial neuropathy and asymptomatic temporal lobe necrosis were found in 2.3% and 1.5% patients. Conclusion: Dose and volume de-escalated IMRT was associated with high PFS and mild late neurological toxicities for IC responders. Further exploration of de-escalation strategies in appropriate patients is needed. Clinical trial registration: Clinical trials.gov identifier: NCT03389295.