Epidemiological trends of neuroendocrine tumours over three decades in Queensland, Australia

Abstract

IntroductionWhile neuroendocrine tumours (NETs) account for only a small proportion of cancer diagnoses, incidence has been rising over time. We examined incidence, mortality and survival over three decades in a large population-based registry study. MethodsThis retrospective study included all cases (n = 4580) of NETs diagnosed from 1986 to 2015 in Queensland, Australia. We examined directly age-standardised incidence and mortality rates. The impact on overall survival according to demographic factors and primary site was modelled using multivariable Cox proportional hazards regression (HR). Cause-specific and relative survival were estimated using the Kaplan-Meier survival function. ResultsAnnual incidence increased from 2.0 in 1986 to 6.3 per 100,000 in 2015, while mortality remained stable. The most common primary site was appendix followed by lung, small intestine and rectum. Rectal, stomach, appendiceal and pancreatic NETs had the greatest rate increase, while lung NETs decreased over the same period. Five-year cause-specific survival improved from 69.4% during 1986–1995 to 92.6% from 2006 to 2015. Survival was highest for appendiceal and rectal NETs and lowest for pancreas and unknown primary sites. The risk of dying within five years of diagnosis was about 40% higher for males (HR = 1.41, 95%CI 1.20–1.65) and significantly higher for patients aged over 40 years compared to younger patients (p < 0.001). ConclusionThis study, including 30 years of data, found significantly increasing rates of NETs and confirms results from elsewhere. Increasing survival over time in this study, likely reflects increased awareness, improvements in diagnostic imaging, greater use of endoscopy and colonoscopy, and the development of new therapies.