Improved long-term results of intensity-modulated radiotherapy for a non-endemic European nasopharyngeal carcinoma cohort: single-center retrospective study

Purpose: Report our matured outcomes of European nasopharyngeal carcinoma (NPC) treatment from a non-endemic region in the IMRT era. Methods: We reviewed 109 consecutive patients with biopsy proven NPC treated between 2009 and 2013. All received IMRT as per RTOG 0615. Toxicity was scored accordingly to CTCAE 4.03. Platinum-based chemotherapy was delivered following the Intergroup 0099. Results: Median age of 53 years; 97% Caucasian; 74% male; 72% WHO grade III; 43% Tl; 14% T2; 18% T3, 25% T4; 17% NO; 17% N1; 39% N2; 27% N3. Compliance to adjuvant chemotherapy was 88%. With a median follow up of 56 months, the 4-year local control was 90.2% (88.6% for Tl; 100% for T2; 85% for T3; and 91.7% for T4), the 4-year distant metastases-free survival was 86% and an overall survival rate was 77%. Local control and survival were better in G3 (p < 0.001 and p = 0.032, respectively). Xerostomia was the most frequent late toxicity in 55% (n = 60). Hypothyroidism requiring hormonal reposition occurred in 15.5% (n = 17). From the 36 deaths, 20 were due to distant metastases, 3 grade 5 toxicity, 2 from local progression, 5 non-cancer deaths and unknown cause in the remaining 6. On multivariable analysis, age (p = 0.017), local recurrence and distant metastases were associated with death (p <0.001, both). Conclusion: Our matured data from the IMRT era showed a major improvement from our 3D cohort series reaching excellent local and regional control, even in T4. Local recurrences, despite few, and distant metastases were correlated with the risk of death. (C) 2020 Greater Poland Cancer Centre. Published by Elsevier B.V. All rights reserved.