Poorer survival in Indigenous Australians following liver cancer can be largely explained by sociodemographic factors, the GESA AGW 2020 was told.

Professor Alan Wigg presented a detailed study of HCC epidemiology in a population of about 4,000 patients from across South Australia, the Northern Territory and Queensland.

About 6.0% of the patients were Indigenous Australians.

Professor Wigg, head of hepatology and transplant medicine at the Flinders Medical Centre, said Indigenous HCC patients were more likely to be younger (17% v 7.1% <50 yrs at diagnosis) and female (31.4% v 18.4%) than non-Indigenous patients.

They were also much more likely to live in remote or very remote regions compared to non-Indigenous Australians (52.8% v 2.8%) and be the most socioeconomically disadvantaged (48.1% v 20.7%).

Indigenous Australians with HCC also had a higher comorbidity burden.

Alcohol was the predominant co-factor in HCC and played a larger role in Indigenous than non-Indigenous Australians (54.1% v 39.6%).

Rates of hepatitis were also different between the two groups with hepatitis B more common (25.3% v 9.9%) and hepatitis C less common (16.6% v 27.1%) in Indigenous compared to non-Indigenous Australians.

Fatty liver and obesity rates were similar between the two groups however diabetes was more common in Indigenous Australians (48.0% v 29.3%).

Professor Wigg noted that some combinations of cofactors such as alcohol and hepatitis B were also more common in Indigenous Australians (13.5% v 3.5%).

And overall, Indigenous Australians were more likely to have two or more cofactors than non-Indigenous Australians (51.1% v 32.5%).

“In terms of treatment, we were able to identify that Indigenous HCC patients received less treatment and that was significant for liver resection, trans arterial chemoembolisation, any HCC treatment and importantly, curative treatment,” he said.

The rate of curative treatment received by Indigenous patients was less than half the rate of that received by other patients (6.6% v 14.5%).

“If we look at survival curves, they are significantly different with poorer survival in the Indigenous cohort.”

Five-year survival in Indigenous patients with HCC was 10.0% compared to 17.3% for other HCC patients (p<0.001).

“Finally, if we look at predictors of mortality … Indigenous status is a significant predictor but there were also a lot of other predictors that were significant on the unadjusted analysis including age, year of diagnosis, rurality, comorbidities … cirrhosis and receipt of curative therapy.”

In a multivariate analysis however, Indigenous status alone was no longer a significant predictor of mortality. Instead, the most important independent prognostic factors were rurality, comorbidities, particularly more than three, and not receiving curative treatment.

Professor Wigg said a focus on remotely living Indigenous Australians was required in order to improve the situation.

“And we need to try and model culturally appropriate interventions at the local level.”

He said screening of at-risk individuals, implementation of an ultrasound surveillance program, and increasing access to treatment were warranted.