Novel population‐based study finding higher than reported hepatocellular carcinoma incidence suggests an updated approach is needed

Thai P Hong, Paul Gow, Michael Fink, Anouk Dev, Stuart Roberts, Amanda Nicoll, John Lubel, Ian Kronborg, Niranjan Arachchi, Marno Ryan, William Kemp, Virginia Knight, Helen Farrugia, Vicky Thursfield, Paul Desmond, Alexander J Thompson, Sally Bell

Background Hepatocellular carcinoma (HCC) incidence is rising rapidly in many developed countries. Primary epidemiological data has invariably been derived from cancer registries that are heterogeneous in data quality and registration methodology; many registries have not adopted current clinical diagnostic criteria for HCC and still rely on histology for classification. We performed the first population-based study in Australia using current diagnostic criteria, hypothesizing that HCC incidence may be higher than reported. Method Incident cases of HCC (defined by AASLD diagnostic criteria or histology) were prospectively identified over a 12-month period (2012-2013) from the population of Melbourne, Australia. Cases were captured from multiple sources: admissions to any of Melbourne's seven tertiary hospitals, attendances at outpatients, radiology, pathology and pharmacy services. Our cohort was compared to the Victorian Cancer Registry (VCR) cohort (mandatory notified cases) for the same population and period, and incidence rates were compared for both cohorts. Results There were 272 incident cases (79% male, median age 65 years) identified. Cirrhosis was present in 83% of patients, with HCV infection (41%), alcohol (39%), and HBV infection (22%) the commonest aetiologies present. Age-standardized HCC incidence (per 100,000, Australian Standard Population) was 10.3 (95%CI: 9.0 to 11.7) for males and 2.3 (95%CI: 1.8 to 3.0) for females. The VCR reported significantly lower rates of HCC: 5.3 (95%CI: 4.4 to 6.4) and 1.0 (95%CI: 0.7 to 1.5) per 100,000 males and females respectively, p<0.0001. Conclusion HCC incidence in Melbourne is two-fold higher than reported by cancer registry data due to underreporting of clinical diagnoses. Adoption of current diagnostic criteria and additional capture sources will improve registry completeness. Chronic viral hepatitis and alcohol remain leading causes of cirrhosis and HCC. This article is protected by copyright. All rights reserved.