Associated factors in recruitment of hispanic participants in a genome-wide association study of colorectal cancer in California

Hispanics represent the fastest growing ethnic population in the U.S. and have been largely understudied in terms of genetic susceptibility to cancer. We are conducting a genome-wide association study (GWAS) in the Hispanic population in California to identify potential genetic and environmental risk factors. Genome-wide association studies of colorectal cancer (CRC) have been instrumental in identifying a number of common susceptibility loci in Non-Hispanic White populations and an NCI priority is to extend GWAS findings to other populations to address racial/ethnic disparities in cancer susceptibility. In our recruitment effort cases are been identified using the California Cancer Registry, however, 10% of the cases received have been deemed ineligible and 20% have incorrect or outdated contact information. In order to establish more effective recruitment efforts we performed an analysis of demographic factors to identify which factors are associated with participation. Descriptive statistical testing using Student's t-tests and chi-squared analyses were performed to evaluate differences is in age at diagnosis, gender, year of diagnosis, geographical region, and language spoken between participants and those that declined to participate. Overall, respondents that indicated a willingness to participate in the study were younger (p <0.0001), Spanish-speaking (p=0.0004), and from the Southern California region (not including Los Angeles) (p=0.0016). In conclusion, the importance of bilingual staff has been is essential to successful recruitment methods. Demographic factors that may be associated with a patient's willingness to participate should be monitored in future studies to maximize participation in cancer studies involving Hispanics as participants.