Equity of timely access to liver and stomach cancer surgery for Indigenous patients in New Zealand: a national cohort study.

Abstract

When combined, liver and stomach cancers are second only to lung cancer as the most common causes of cancer death for the indigenous Māori population of New Zealand-with Māori also experiencing substantial disparities in the likelihood of survival once diagnosed with these cancers. Since a key driver of this disparity in survival could be access to surgical treatment, we have used national-level data to examine surgical procedures performed on Māori patients with liver and stomach cancers and compared the likelihood and timing of access with the majority European population. We examined all cases of liver and stomach cancers diagnosed during 2007-2019 on the New Zealand Cancer Registry (liver cancer: 866 Māori, 2460 European; stomach cancer: 953 Māori, 3192 European) and linked these cases to all inpatient hospitalisations that occurred over this time to identify curative and palliative surgical procedures. As well as descriptive analysis, we compared the likelihood of access to a given procedure between Māori and Europeans, stratified by cancer and adjusted for confounding and mediating factors. Finally, we compared the timing of access to a given procedure between ethnic groups. We found that (a) access to liver transplant for Māori is lower than for Europeans; (b) Māori with stomach cancer appear more likely to require the type of palliation consistent with gastric outlet obstruction; and (c) differential timing of first stomach cancer surgery between Māori and European patients. However, we may also be cautiously encouraged by the fact that differences in overall access to curative surgical treatment were either marginal (liver) or absent (stomach).