Ethnic and Socio-Economic Variations in Comorbidity and Mortality in Cancer Survivors: A UK Population-Based Observational Study

The population of cancer survivors is increasing rapidly in the UK. Little is known about the variation in comorbidity and mortality by ethnicity and socio-economic condition in this population. This study explores these variations using primary care data from the Clinical Practice Research Datalink (CPRD) and linked secondary care data. The prevalence of multimorbidity and risk of mortality were calculated for Asian, Black, and Other ethnic and socio-economic groups in England, consisting of 333,226 cancer survivors across 28 cancer types. Odds ratios and hazard ratios were calculated using the White and most affluent groups as references and adjusted for age, sex, BMI, and smoking status. Stratified mortality analysis was conducted for survivors of the six common cancers in the UK: breast, prostate, colorectal, bladder, cervical, and lung. Compared to White cancer survivors, survivors of all other ethnic groups had a statistically significant higher prevalence of type 2 diabetes (Asian adjusted odds ratio (OR) 4.61 (4.02-5.28), Black OR 1.87 (1.52-2.30), and Other OR 2.06 (1.64-2.59)). However, they had lower prevalences of depression and anxiety. Asian survivors exhibited the highest overall prevalence of comorbidity. Black survivors had the worst survival (adjusted hazard ratio (HR) 1.48 (1.38-1.59)) for all cancers combined, as well as for breast, prostate, colorectal, and cervical cancers. Black breast cancer survivors face a particularly high mortality risk (HR 1.78 (1.52-2.10)) compared to Whites. Asian survivors had higher mortality for all cancers combined (HR 1.31 (1.23-1.39)) and specifically for lung cancer (HR 1.81 (1.44-2.28)). The Other ethnic group had a significantly increased risk of mortality in cervical cancer (HR 1.90 (1.19-3.03)). The risk of mortality increased with worse socio-economic conditions, regardless of ethnic group. Cancer survivors of non-White ethnicity and poorer socio-economic background in the UK have worse outcomes in terms of increased prevalence of multimorbidity and mortality compared to White survivors. These findings indicate the need to comprehend the underlying reasons for these disparities and to assess the implications for cancer services, patient experience, and overall outcomes.