Ethnic disparity in cancer mortality in adult Fijian women, 2013-17

Abstract Background Fiji, population 884,887 (2017 census), is a Pacific Island country with two dominant ethnic groups: 62% Indigenous Fijians (i-Taukei) and 31% Fijians of Indian descent (FID). Cancer mortality by ethnicity for women aged 30-69 years was investigated. Methods Proportional mortality and probability of dying (PoD30-70) from cancer (ICD-10: C00-D48) for women aged 30-69 years were calculated from empirical unit mortality data by ethnicity. PoD30-70 is the cumulative mortality risk derived from the cumulative rate, from mortality rates by 5-year age group. Results Cancer was reported as the underlying cause in 21% of deaths of Fijian women aged 30-69 years; 25% for i-Taukei and 14% for FID women. This ethnic disparity was consistent across cancer sites, including breast, cervical/uterine and ovarian cancers. Empirically derived PoD30-70 from all cancers (ICD-10 C00-D48) was 9.6% (95%CI: 9.1-10.1%) for Fijian women; higher for i-Taukei (12.1%; 95%CI: 11.4-12.8%) than FID women (6.6%; 95%CI: 5.9-7.2%). Globocan 2020 estimates the highest PoD30-70 from all cancers in women was 10.8% in Malawi; for Fiji, Globocan estimates of 9.2%, from 2008-2012 mortality rates applied to the 2020 population, are comparable to empirically derived PoD30-70. From empirical data, PoD30-70 from breast cancer for Fijian women was 2.9% (95%CI: 2.6-3.1%), higher in i-Taukei (3.8%; 95%CI: 3.4-4.2%) and lower in FID women (1.7%; 95%CI: 1.4-2.1%). Globocan 2020 estimates of PoD30-70 due to breast cancer was highest in Barbados (3.6%), followed by Fiji (3.4%). PoD30-70 due to cervical/uterine and ovarian cancer was approximately double for i-Taukei (3·2 and 1·0%) compared to FID women (1·5 and 0·5%). Conclusions PoD30-70 due to breast cancer and all cancers was higher in i-Taukei Fijian women than in other countries and was double that of FID women. High incidence and late diagnosis contribute to high cancer mortality; differences between i-Taukei and FID women require further investigation. Key messages • Probability of dying due to breast cancer, and all cancers, was higher for i-Taukei women in Fiji than for women in other countries, and double that of Fijian women of Indian descent. • High incidence and late diagnosis contribute to high cancer mortality; further investigation is required to determine how these, and other potential factors, contribute to ethnic differences.