The Lancet Regional Health. Western Pacific (Jul 2022)
Cancer of the nasopharynx in Aotearoa New Zealand from 1994 to 2018: Incidence and survival in a population-based, national registry cohort study
Abstract
Summary: Background: Cancer of the nasopharynx has remarkable geographic and ethnic variation in incidence and outcomes globally. Recent advances in diagnostic and therapeutic technologies provide new opportunities for early detection and improved outcomes. This study aimed to determine the incidence, demographics, outcomes and time trends of cancer of the nasopharynx in Aotearoa New Zealand over the last 25 years. Methods: In a population-based, national registry cohort study of notifications of malignant neoplasms of the nasopharynx made to the New Zealand Cancer Registry between 1994 and 2018, age-specific and age-standardised incidence rates and survival outcomes were evaluated. Findings: 577 registrations of nasopharyngeal cancer from between 1994 and 2018 were analysed; median age at diagnosis 54 years; 72.4% male; 37.4% Asian, 24.3% New Zealand European, 25.3% Pacific peoples, 13.0% Māori. Age-standardised annual incidence remained low (<1/100,000 person-years) and stable from 1994 to 2018. Age-standardised incidence rates in Pacific peoples, Asian and Māori were 21 (95% CI 12.07-35.21)-, 17 (10.95-25.33)- and 4 (2.79-7.07)-fold higher, respectively, than New Zealand Europeans. Epstein-Barr virus-related morphologies predominated keratinising squamous cell carcinoma and not-otherwise-specified morphological subtypes. Ten-year overall survival rate for the cohort was 49.2% (95% CI 44.7-53.5). Older age at diagnosis (65–94 years), Māori or Pacific ethnicity, keratinising squamous cell carcinoma and distant disease were associated with shorter overall survival, whereas younger age at diagnosis (10-29 years), and Asian ethnicity were associated with longer survival. Interpretation: Aotearoa New Zealand has a distinct profile of nasopharyngeal cancer, with age, ethnicity and morphology among the main determinants of incidence and survival. Funding: None.
