Socioeconomic Determinants of the Use of Molecular Testing in Stage IV Colorectal Cancer. (December 2021)

• Record Type: Journal Article
• Authors: Punekar, Salman R.; Griffin, Megan M.; Masri, Lena; Roman, Stefanie D.; Makarov, Danil V.; Sherman, Scott E.; Becker, Daniel J.
• Is Part Of: American journal of clinical oncology. Volume 44:Number 12(2021)
• Publication Date: 2021-12
• Subjects: colorectal cancer -- KRAS testing -- wild-type EGFR -- socioeconomic status; Cancer -- Treatment -- Periodicals; Oncology -- Periodicals; Tumors -- Periodicals; 616.994005
• DOI: 10.1097/COC.0000000000000875
• Languages: English
• ISSNs: 0277-3732

Abstract

Abstract : Objectives: Treatment with epidermal growth factor receptor monoclonal antibodies extends life for patients with advanced colorectal cancers (CRCs) whose tumors exhibit wild-type KRAS, but KRAS testing may be underused. We studied the role of socioeconomic factors in the application of KRAS testing. Materials and Methods: We identified subjects with stage IV colorectal adenocarcinoma diagnosed 2010-2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We used multivariable logistic regression models to evaluate associations between clinical/demographic factors and the rate of KRAS testing. We used multivariable-adjusted Cox proportional hazards models to assess survival. Results: We identified 37, 676 patients with stage IV CRC, 31.1% of whom were tested for KRAS mutations, of those who had documented KRAS testing, 44% were KRAS mutant. Patients were more likely to be tested if they were younger (odds ratio [OR]=5.10 for age 20 to 29 vs. 80+, 95% confidence interval [CI]: 3.99-6.54, P <0.01), diagnosed more recently (OR=1.92 for 2015 vs. 2010, 95% CI: 1.77-2.08, P <0.01), or lived in an area of high median household income (OR=1.24 for median household income of >$69, 311 vs. <$49, 265, 95% CI: 1.14-1.35, P <0.01). Patients were less likely to be tested if they had Medicaid (OR=0.83, 95% CI: 0.77-0.88, P <0.01) or were unmarried (OR=0.78, 95% CI: 0.75-0.82, P <0.0001). The risk of death was decreased in patients who received KRAS testing (hazard ratio=0.77, 95% CI: 0.75-0.80, P <0.01). Conclusions: We found a low rate of KRAS testing in CRC patients with those living in low-income areas less likely to be tested, even after controlling for Medicaid insurance. Our study suggests that socioeconomic disparities persist despite Medicaid insurance. Abstract : Supplemental Digital Content is available in the text.