The Role of Stage at Diagnosis in Colorectal Cancer Black–White Survival Disparities: A Counterfactual Causal Inference Approach
Year: 2015
Type: article
Study design: Observational Study
Abstract: BACKGROUND: To date, a counterfactual framework has not been used to study determinants of social inequalities in cancer. Considering the case of colorectal cancer, for which racial/ethnic differences in stage at diagnosis and survival are well documented, we quantify the extent to which black versus white survival disparities would be reduced had disparities in stage at diagnosis been eliminated in a large patient population. METHODS: We obtained data on colorectal cancer patients (diagnosed between 1992 and 2005 and followed until 2010) from US-SEER (Surveillance, Epidemiology, and End Results) cancer registries. We employed a counterfactual approach to estimate the mean survival time up to the 60th month since diagnosis for black colorectal cancer patients had black-white disparities in stage at diagnosis been eliminated. RESULTS: Black patients survive approximately 4.0 [confidence interval (CI), 4.6-3.2] months less than white patients within five years since diagnosis. Had disparities in stage at diagnosis been eliminated, survival disparities decrease to 2.6 (CI, 3.4-1.7) months, an approximately 35% reduction. For patients diagnosed after the age of 65 years, disparities would be halved, while reduction of approximately 30% is estimated for younger patients. Survival disparities would be reduced by approximately 44% for women and approximately 26% for men. CONCLUSIONS: Employing a counterfactual approach and allowing for heterogeneities in black-white disparities across patients' characteristics, we give robust evidence that elimination of disparities in stage at diagnosis contributes to a substantial reduction in survival disparities in colorectal cancer. IMPACT: We provide the first evidence in the SEER population that elimination of inequities in stage at diagnosis might lead to larger reductions in survival disparities among elderly and women.
Institutions: Harvard University, McLean Hospital
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: Identification and Inference for Longitudinal Causal Mediation Analysis in HIV, Theory and methods for sufficient cause interactions, Vermont PROSPR Research Center (VPRC), Lung Cancer Disparities Center: Jointly Addressing Race & Socioeconomic Status, Breast Carcinoma in situ: Predicting Risk and Outcomes, Theory and methods for interaction, Statistical Informatics for Cancer Research, Vermont Center on Behavior and Health, UW Comprehensive Cancer Center Support, Statistical Methods for Analysis of Massive Genetic and Genomic Data in Cancer Research
OpenAlex ID: W2215202924