Factors Associated With Guideline-recommended KRAS Testing in Colorectal Cancer Patients: A Population-based Study

Mary E Charlton; Jordan J Karlitz; Jennifer A Schlichting; Vivien W Chen; Charles F Lynch

doi:10.1097/COC.0000000000000191

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Factors Associated With Guideline-recommended KRAS Testing in Colorectal Cancer Patients: A Population-based Study

Journal article

Peer reviewed

Factors Associated With Guideline-recommended KRAS Testing in Colorectal Cancer Patients: A Population-based Study

Mary E Charlton, Jordan J Karlitz, Jennifer A Schlichting, Vivien W Chen and Charles F Lynch

American journal of clinical oncology, Vol.40(5), pp.498-506

10/2017

DOI: 10.1097/COC.0000000000000191

PMCID: PMC4591083

PMID: 25844824

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Abstract

Response to epidermal growth factor receptor inhibitors is poorer among stage IV colorectal cancer (CRC) patients with KRAS mutations; thus KRAS testing is recommended before treatment. KRAS testing was collected by Surveillance, Epidemiology, and End Results (SEER) registries for 2010 CRC cases, and our goal was to provide the first population-based estimates of testing in the United States. SEER CRC cases diagnosed in 2010 were evaluated (n=30,351). χ tests and logistic regression were conducted to determine patient characteristics associated with KRAS testing, stratified by stages I-III versus stage IV. Log-rank tests were used to examine survival by testing status. KRAS testing among stage IV cases ranged from 39% in New Mexico to 15% in Louisiana. In the model, younger age, being married, living in a metropolitan area, and having primary site surgery were associated with greater odds of receiving KRAS testing. Those who received testing had significantly better survival than those who did not (P<0.0001). Among those who received testing, there was no significant difference in survival by mutated versus wild-type KRAS. Five percent of stage I-III cases received testing. Wide variation in documented KRAS testing for stage IV CRC patients exists among SEER registries. Age remained highly significant in multivariate models, suggesting that it plays an independent role in the patient and/or provider decision to be tested. Further research is needed to determine drivers of variation in testing, as well as reasons for testing in stage I-III cases where it is not recommended.

Mutation

United States

Colorectal Neoplasms - mortality

SEER Program

Proto-Oncogene Proteins p21(ras) - genetics

Colorectal Neoplasms - genetics

Humans

Middle Aged

DNA Mutational Analysis - statistics & numerical data

DNA Mutational Analysis - utilization

Survival Analysis

Aged, 80 and over

Adult

Female

Aged

Colorectal Neoplasms - pathology

Details

Title: Subtitle: Factors Associated With Guideline-recommended KRAS Testing in Colorectal Cancer Patients: A Population-based Study
Creators: Mary E Charlton - University of Iowa, Epidemiology
Jordan J Karlitz
Jennifer A Schlichting
Vivien W Chen
Charles F Lynch - University of Iowa, Epidemiology
Resource Type: Journal article
Publication Details: American journal of clinical oncology, Vol.40(5), pp.498-506
DOI: 10.1097/COC.0000000000000191
PMID: 25844824
PMCID: PMC4591083
NLM abbreviation: Am J Clin Oncol
ISSN: 0277-3732
eISSN: 1537-453X
Publisher: United States
Grant note: P30 ES005605 / NIEHS NIH HHS HHSN261201000032C / NCI NIH HHS P30 CA086862 / NCI NIH HHS HHSN261201000030C / NCI NIH HHS
Language: English
Date published: 10/2017
Academic Unit: Health Management and Policy; Epidemiology
Record Identifier: 9983995006502771

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