Cholangiocarcinoma across England: Temporal changes in incidence, survival and routes to diagnosis by region and level of socioeconomic deprivation.

ABSTRACT

Background & Aims: While cholangiocarcinoma (CCA) incidence and mortality rates are increasing globally, whether there are regional/temporal variations in these rates for different biliary tract cancer (BTC) subtypes, or whether they differ by sex, socioeconomic status, or route to diagnosis (RtD) remains unknown. In this work, we aimed to perform an in-depth analysis of data on the incidence, mortality, survival and RtD of CCA and other BTCs. Methods: Data on all BTCs diagnosed in England between 2001 and 2018 were extracted from NHS Digital's National Cancer Registration Dataset. Age-standardised incidence rates (ASRs), mortality rates (ASMRs) and net survival rates were calculated, and Kaplan-Meier overall survival estimates and RtD trends were analysed. Analyses were stratified by sex, socioeconomic deprivation, tumour subtype and region. Results: The ASR for CCA rose from 2.9 in 2001-2003 to 4.6 in 2016-2018 and from 1.0 to 1.8 for gallbladder cancers (GBCs). ASMR trends mirror those of incidence, with most deaths due to iCCA. Over 20% of patients with CCA were under 65 years old. The ASRs and ASMRs were consistently higher in the most socioeconomically deprived group for CCA and GBC. The most common RtD was the emergency route (CCA 49.6%, GBC 46.2% and ampulla of Vater cancer 43.0%). The least deprived patients with CCA and ampulla of Vater cancer had better overall survival (p <0.001). Net survival rates rose for all BTCs, with 3-year net survival for CCA increasing from 9.2% in 2001 to 12.6% in 2016-2018. There was notable geographical variation in ASRs, ASMRs and net survival for all BTCs. Conclusions: BTC incidence and mortality rates are increasing, with differences observed between tumour types, socioeconomic deprivation groups, RtDs and geographical regions. This highlights the need for targeted interventions, earlier diagnosis and better awareness of this condition amongst the public and healthcare professionals. Impact and implications Cholangiocarcinoma (CCA) incidence and mortality rates are rising globally, particularly for intrahepatic CCA. However, it has not previously been reported if, within a single country, there are temporal and regional differences in incidence, mortality and survival rates for different biliary tract subtypes, and whether these differ by sex, socioeconomic status, or route of diagnosis. In this study we show that mortality rates for patients with CCA continue to rise and are almost 40% higher in the most socioeconomically deprived compared to the least; additionally, we observed regional variation within England in incidence, mortality and survival. This study is relevant to researchers and policy makers as it highlights regional variation and inequality, as well as emphasising the need for earlier diagnosis and better awareness of this condition amongst the public and healthcare professionals.