Original Article
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World J Gastroenterol. Feb 14, 2014; 20(6): 1544-1553
Published online Feb 14, 2014. doi: 10.3748/wjg.v20.i6.1544
Incidence and mortality of primary liver cancer in England and Wales: Changing patterns and ethnic variations
Nimzing G Ladep, Shahid A Khan, Mary ME Crossey, Andrew V Thillainayagam, Simon D Taylor-Robinson, Mireille B Toledano
Nimzing G Ladep, Shahid A Khan, Mary ME Crossey, Andrew V Thillainayagam, Simon D Taylor-Robinson, Gastroenterology and Hepatology Section, Division of Diabetes Endocrinology and Metabolism, Department of Medicine, Imperial College London, London W2 1PG, United Kingdom
Mireille B Toledano, MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London W2 1PG, United Kingdom
Author contributions: Ladep NG conceptualised, designed, analysed, wrote and submitted data for publication; Khan SA supervised data analyses, writing and provided intellectual support; Crossey MME provided intellectual and literary contribution; Thillainayagam AV participated in writing, review and supervision of the data; Taylor-Robinson SD participated in the design, supervision, writing and overall aspects of the study; Toledano MB is the custodian of the data from Small Area Health Statistics Unit, she supervised all aspects of the study and approved the journal to be submitted to.
Correspondence to: Dr. Mireille B Toledano, MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, Imperial College London, St Mary’s Campus, Norfolk Place, London, W2 1PG, United Kingdom. m.toledano@imperial.ac.uk
Telephone: +44-20-75943298 Fax: +44-20-75943298
Received: September 12, 2013
Revised: November 18, 2013
Accepted: December 3, 2013
Published online: February 14, 2014
Processing time: 158 Days and 12.1 Hours
Abstract

AIM: To explore recent trends, modes of diagnosis, ethnic distribution and the mortality to incidence ratio of primary liver cancer by subtypes in England and Wales.

METHODS: We obtained incidence (1979-2008) and mortality (1968-2008) data for primary liver cancer for England and Wales and calculated age-standardised incidence and mortality rates. Trends in age-standardised mortality (ASMR) and incidence (ASIR) rates and basis of diagnosis of primary liver cancer and subcategories: hepatocellular carcinoma, intrahepatic bile duct and unspecified liver tumours, were analysed over the study period. Changes in guidelines for the diagnosis of primary liver cancer (PLC) may impact changing trends in the rates that may be obtained. We thus explored changes in the mode of diagnosis as reported to cancer registries. Furthermore, we examined the distribution of these tumours by ethnicity. Most of the statistical manipulations of these data was carried out in Microsoft excel® (Seattle, Washington, United Sttaes). Additional epidemiological statistics were done in Epi Info software (Atlanta, GA, United Sttaes). To define patterns of change over time, we evaluated trends in ASMR and ASIR of PLC and intrahepatic bile duct carcinoma (IHBD) using a least squares regression line fitted to the natural logarithm of the mortality and incidence rates. We estimated the patterns of survival over subsequent 5 and 10 years using complement of mortality to incidence ratio (1-MIR).

RESULTS: Age-standardised mortality rate of primary liver cancer increased in both sexes: from 2.56 and 1.29/100000 in 1968 to 5.10 and 2.63/100000 in 2008 for men and women respectively. The use of histology for diagnostic confirmation of primary liver cancer increased from 35.7% of registered cases in 1993 to plateau at about 50% during 2005 to 2008. Reliance on cytology as a basis of diagnosis has maintained a downward trend throughout the study period. Although approximately 30% of the PLC registrations had information on ethnicity, there was a relatively higher registration of the major tumour subtypes in patients whose ethnic backgrounds were from high incident regions of the world. Survival from PLC is estimated to get poorer in 10 years (2018) relative to 2008, particularly as a result of IHBD.

CONCLUSION: Incidence and mortality of PLC, and particularly IHBD, have continued to rise in England and Wales. Changes in the modes of diagnosis may be contributing.

Keywords: Primary liver cancer; Hepatocellular carcinoma; Intrahepatic bile duct; England and Wales; Ethnicity

Core tip: It has been widely reported that primary liver cancer (PLC) has a poor prognosis and is increasing in many industrialised countries. We highlight an ongoing increase in the incidence of PLC in England and Wales, rendering artefactual explanations for the increase ever less convincing and, for the first time, describe ethnic variability in the incidence. More widespread use of histology in the confirmation of PLC is being embarked upon in England and Wales. These findings suggest that more aggressive screening efforts would be beneficial in England and Wales so as to improve survival. Targeted prevention programmes, including vaccination of at-risk population may be worthwhile.