Racial-Ethnic Disparities in Late-Stage Colorectal Cancer Among Hispanics and Non-Hispanic Whites of New Mexico

INTRODUCTION

Hispanics in New Mexico are diagnosed with more later-stage colorectal cancer (CRC) than non-Hispanic Whites (NHW). Our study evaluated the interaction of race/ethnicity and risk factors for later-stage III and IV CRC among patients in New Mexico.

METHOD

CRC patients ages 30 to 75 years ( n = 163, 46% Hispanic) completed a survey on key explanatory clinical, lifestyle, preventive health, and demographic variables for CRC risk. Adjusted logistic regression models examined whether these variables differentially contributed to later-stage CRC among NHW versus Hispanics.

RESULTS

Compared with NHW, Hispanics had a higher prevalence of later-stage CRC ( p = .007), diabetes ( p = .006), high alcohol consumption ( p = .002), low education ( p = .003), and CRC diagnosis due to symptoms ( p = .06). Compared with NHW, Hispanics reporting high alcohol consumption (odds ratio [OR] = 7.59; 95% confidence interval [CI] = 1.31-43.92), lower education (OR = 3.5; 95% CI = 1.28-9.65), being nondiabetic (OR = 3.23; 95% CI = 1.46-7.15), or ever smokers (OR = 2.4; 95% CI = 1.03-5.89) were at higher risk for late-stage CRC. Adjusting for CRC screening did not change the direction or intensity of the odds ratios.

CONCLUSION

The ethnicity-risk factor interactions, identified for late-stage CRC, highlight significant factors for targeted intervention strategies aimed at reducing the burden of later-stage CRC among Hispanics in New Mexico with broad applicability to other Hispanic populations.

KRAS biomarker testing disparities in colorectal cancer patients in New Mexico

Introduction

American Society of Clinical Oncology (ASCO) guidelines recommend that all patients with metastatic colorectal cancer (mCRC) receive KRAS testing to guide anti-EGFR monoclonal antibody treatment. The aim of this study was to assess for disparities in KRAS testing and mutational status.

Methods

The New Mexico Tumor Registry (NMTR), a population-based cancer registry participating in the National Cancer Institute's Surveillance, Epidemiology and End Results program, was queried to identify all incident cases of CRC diagnosed among New Mexico residents from 2010 to 2013.

Results

Six hundred thirty-seven patients were diagnosed with mCRC from 2010-2013. As expected, KRAS testing in Stage 4 patients presented the highest frequency (38.4%), though testing in stage 3 (8.5%), stage 2 (3.4%) and stage 1 (1.2%) was also observed. In those with metastatic disease, younger patients (≤ 64 years) were more likely to have had testing than patients 65 years and older (p < 0.0001). Patients residing in urban areas received KRAS testing more often than patients living in rural areas (p = 0.019). No significant racial/ethnic disparities were observed (p = 0.66). No significant differences were seen by year of testing.

Conclusion

Age and geographic disparities exist in the rates of KRAS testing, while sex, race/ethnicity and the year tested were not significantly associated with testing. Further study is required to assess the reasons for these disparities and continued suboptimal adherence to current ASCO KRAS testing guidelines.