Background: In 2011, the National Comprehensive Cancer Network (NCCN) recommended KRAS testing for metastatic colorectal cancer (mCRC) patients. Our study assessed KRAS testing prevalence and its association with socio-demographic and clinical factors and examined first-line treatment.
Methods: Ten state population-based registries supported by Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR) collected detailed cancer information on mCRC cases diagnosed in 2011, including KRAS biomarker testing and first-line treatment from ten central cancer registries. Data were analyzed with Chi-square tests and multivariate logistic regression.
Results: Of the 3,608 mCRC cases, 27% (n = 992) had a documented KRAS test. Increased age at diagnosis (p < 0.0001), racial/ethnic minorities (p = 0.0155), public insurance (p = 0.0018), and lower census tract education (p = 0.0023) were associated with less KRAS testing. Significant geographic variation in KRAS testing (p < 0.0001) ranged from 46% in New Hampshire to 18% in California. After adjusting for all covariates, age and residence at diagnosis (both p < 0.0001) remained predictors of KRAS testing. Non-Hispanic Blacks had less KRAS testing than non-Hispanic Whites (OR = 0.77, 95% CI = 0.61-0.97). Among those tested and found to have normal (wild-type) KRAS, 7% received anti-EGFR treatment; none received such treatment among those with KRAS mutated gene.
Conclusions: Despite NCCN guideline recommendations, 73% of mCRC cases diagnosed in 2011 had no documented KRAS test. Disparities in KRAS testing existed based on age, race, and residence at diagnosis.
Impact: These findings show the capacity of monitoring KRAS testing in the US using cancer registry data and suggest the need to understand the low uptake of KRAS testing, and associated treatment choices during the first year since diagnosis.
Keywords: KRAS testing; NPCR registries; colorectal cancer.
KRAS biomarker testing disparities in colorectal cancer patients in New Mexico.Heliyon. 2017 Nov 21;3(11):e00448. doi: 10.1016/j.heliyon.2017.e00448. eCollection 2017 Nov. Heliyon. 2017. PMID: 29202108 Free PMC article.
KRAS testing and epidermal growth factor receptor inhibitor treatment for colorectal cancer in community settings.Cancer Epidemiol Biomarkers Prev. 2013 Jan;22(1):91-101. doi: 10.1158/1055-9965.EPI-12-0545. Epub 2012 Nov 15. Cancer Epidemiol Biomarkers Prev. 2013. PMID: 23155138 Free PMC article.
Recommendations from the EGAPP Working Group: can testing of tumor tissue for mutations in EGFR pathway downstream effector genes in patients with metastatic colorectal cancer improve health outcomes by guiding decisions regarding anti-EGFR therapy?Genet Med. 2013 Jul;15(7):517-27. doi: 10.1038/gim.2012.184. Epub 2013 Feb 21. Genet Med. 2013. PMID: 23429431
Metastatic colorectal cancer treatment patterns according to kirsten rat sarcoma viral oncogene homolog genotype in U.S. Community-based oncology practices.Clin Colorectal Cancer. 2014 Sep;13(3):178-84. doi: 10.1016/j.clcc.2014.05.001. Epub 2014 Jun 23. Clin Colorectal Cancer. 2014. PMID: 25065655
KRAS status and resistance to epidermal growth factor receptor tyrosine-kinase inhibitor treatment in patients with metastatic colorectal cancer: a meta-analysis.Colorectal Dis. 2014 Nov;16(11):O370-8. doi: 10.1111/codi.12749. Colorectal Dis. 2014. PMID: 25155261 Review.