Pattern of Failure in Nasopharyngeal Carcinoma After Radiotherapy in a Low‐Incidence Population: A DAHANCA Study

ABSTRACT Background Nasopharyngeal carcinoma (NPC) is uncommon in many populations. Most existing clinical evidence comes from endemic areas, where Epstein–Barr virus (EBV)‐associated subtypes predominate. We analyzed patterns of failure in a population‐based cohort from Denmark, a low‐incidence setting. Methods Patients with NPC treated with curative intent between 2000 and 2018 were identified through the Danish Head and Neck Cancer Study Group (DAHANCA) database and subsequently validated. Results We identified 331 patients. The 5‐year cumulative incidence of failure was 31.1% for any failure, 16.9% for locoregional failure, and 14.2% for distant failure. Distant failure occurred almost exclusively in locally advanced disease (Stage I: 0%; II: 4.2%; III: 21.1%; and IVa: 19.4%). Rates of any failure were comparable between EBV‐positive (29.7%) and EBV‐negative (32.0%) tumors. Conclusions In this low‐incidence population, the likelihood of failure after primary radiotherapy for NPC did not differ by EBV status. Distant failure was largely confined to patients with locally advanced stages.