A multicenter, randomized controlled phase III trial of TPF induction chemotherapy versus PF adjuvant chemotherapy combined with concurrent chemoradiotherapy in locally advanced nasopharyngeal carcinoma: Long-term follow-up analysis.

6100 Background: To investigate whether TPF induction chemotherapy combined with concurrent chemoradiotherapy (CCRT) can provide greater survival benefits compared to CCRT followed by PF adjuvant chemotherapy. Methods: Patients with newly diagnosed locally advanced (Stage III–IVA) nasopharyngeal carcinoma (NPC) treated at the Affiliated Tumor Hospital of Guizhou Medical University, the Second Affiliated Hospital of Guizhou Medical University, the Second Affiliated Hospital of Zunyi Medical University, and Guiyang Hospital of Guizhou Aviation from May 2018 to July 2021 were enrolled. Each group included 133 patients. The experimental group received 3 cycles of TPF induction chemotherapy (docetaxel 75mg/m²,intravenous infusion, Day 1; cisplatin 75mg/m²,continuous intravenous infusion over 5 days,10:00–22:00 daily; fluorouracil 750mg/m²/day, continuous intravenous infusion over 5 days, 22:00–10:00 daily) followed by 2–3 cycles of concurrent chemotherapy (cisplatin 100mg/m², continuous intravenous infusion over 2 days, 10:00–22:00 daily). The control group received PF adjuvant chemotherapy (cisplatin 80mg/m², continuous intravenous infusion over 5 days,10:00–22:00 daily; fluorouracil 800mg/m²/day, continuous intravenous infusion over 5 days, 22:00–10:00 daily) combined with 2–3 cycles of concurrent chemotherapy (same as induction chemotherapy).Both groups underwent intensity-modulated radiotherapy (IMRT),with total doses of 69.96 Gy for T1–T2 primary lesions, 72.6 Gy for T3–T4 lesions, and 69.96 Gy for positive lymph nodes. Data were analyzed using SPSS 26.0.Differences in 5-year PFS, OS, LRFS, DMFS, and adverse events were compared between the two groups. Results: No significant differences were observed between the two groups in age, sex, Karnofsky Performance Status (KPS) score, T stage, N stage, or overall stage ( P > 0.05).At a median follow-up of 58 months, the 5-year PFS in both the intention-to-treat and per-protocol populations was similar between the induction chemotherapy (IC) and adjuvant chemotherapy (AC) groups (66.6% vs 66.0%, P = 0.589; 75.3% vs 69.9%, P =0.471). The 5-year OS, LRFS, and DMFS rates were 73.0% vs 71.3% ( P =0.582), 87.4% vs 90.8% ( P =0.508), and 76.9% vs 72.6% ( P =0.267), respectively, with no significant differences. Conclusions: Both groups had similar 5-year PFS, OS, LRFS, DMFS, and long-term toxicity profiles. Clinical trial information: NCT03574324 . 5-year observation indicators for two groups. Observation indicators IC+CCRT CCRT+AC P value Risk ratio(95% CI) PFS ITT Population 66.6% 66.0% 0.589 0.89（0.58-1.36） PP Population 75.3% 69.9% 0.471 0.85（0.55-1.33） OS 73.0% 71.3% 0.582 0.88（0.55-1.39） LRFS 87.4% 90.8% 0.508 1.30（0.60-2.80） DMFS 76.9% 72.6% 0.267 0.75（0.45-1.25） OS, LRFS, and DMFS were all calculated in the ITT population.