Nasopharyngeal carcinoma: nationwide trends in subtype-specific incidence and survival over 3 decades in a non-endemic area

Abstract

PurposeTo identify trends in incidence and survival of NPC, subdivided by EBV status and histopathological subtype, over a 30-year period in the Netherlands.MethodsAnonymized data from the Netherlands Cancer Registry and the Dutch Nationwide Pathology Databank (PALGA) for the period 1989–2018 were linked to identify and classify NPC cases.ResultsIncidence of NPC remained stable, with an annual percentage change (APC) of − 0.2. (95% CI − 0.9; 0.5). EBV testing became routine only in the last decade, the incidence of EBV-positive tumors remained stable over this period (APC 1.2, 95% CI − 1.3; 3.8). An increase in EBV-negative tumors (APC: 7.1, 95% CI 2.5; 11.9) and a decrease in untested tumors were found (APC: − 10.7, 95% CI − 15.7; − 5.7). The incidence of non-keratinizing, differentiated tumors increased (APC: 3.8, (95% CI 2.2; 5.5) while the incidence of other histological subtypes remained stable. Overall survival was better in patients diagnosed after 1998 (hazard ratio 0.8, 95% CI 0.6; 0.9). EBV status, histology, stage, and age were independently associated with relative excess risk of dying, but period of diagnosis was not.ConclusionTesting for EBV increased over time, and a stable incidence of EBV-positive NPC over the last 10 years. The rising incidence of non-keratinizing, differentiated NPC mirrors data from the US and suggests a shift in non-endemic regions.