Epidemiological trends of gallbladder cancer in Australia between 1982 to 2018: A population-based study utilizing the Australian Cancer Database

BACKGROUNDS/AIMS: Gallbladder cancer (GBC) is a rare neoplasm. The epidemiology of GBC has not been updated in Australia for over five decades. METHODS: Data of all Australian patients diagnosed with GBC at any age from 1982 to 2018 were identified from the Australian Cancer Database. Age-standardized rates were calculated and joinpoint analysis was performed to ascertain the trends of incidence and mortality of GBC. RESULTS: Between 1982 and 2018, there were 22,745 cases of GBC and 11,054 GBC-related deaths in Australia. There were three distinct periods showing changed incidence. Period 1 (1982–1995) was stable. Period 2 (1996–2006) showed reduced incidence in females (3.6 to 2.8/100,000; p < 0.01) and all Australians (3.7 to 2.8/100,000, p < 0.01). Period 3 (2006–2017) demonstrated significantly increased incidence in all groups (males: 2.7 to 4.0/100,000, p < 0.01; females: 2.8 to 3.5/100,000, p < 0.01; all Australians: 2.8 to 3.7/100,000, p < 0.01). Incidence between females and males had declined from 1.10 : 1 in 1982 to 0.87 : 1 in 2017. There was a 71% reduction in mortality (3.1 to 0.9/100,000; p < 0.01). Median age at diagnosis increased from 69.7 to 74.3 years for females and from 67.2 to 73.3 years for males. Increasing incidence in the 6th to 8th decade of life in males, compared to previous years, was noted. CONCLUSIONS: Incidence, mortality, sex, and age of GBC have significantly changed in Australia since 1982. Rising incidence of GBC in Australia warrants further investigation.