Abstract FO02-01: Community-based interventions to reduce for colon cancer disparites in African Americans in South Carolina.
Authors: Hebert James R. , Xirasagar Sudha , Hurley Thomas G. , Burch James B. 
Published: August 2014

Background: Compared to many cancers that only can be “downstaged” through screening, cancers of the colon and rectum can be prevented through colonoscopy screening to detect and remove pre-cancerous polyps. Compared to their European-American (EA) counterparts African Americans (AA) have a significantly higher incidence of colorectal cancer, tend to have more aggressive disease, and are diagnosed at generally younger ages. While these disparities are evident nationally, they are more extreme in South Carolina. So, the need for screening for primary disease prevention is most acute among African Americans – and especial in places such as South Carolina. When performed under an adenoma detection-maximizing protocol, colonoscopy screening can reduce colorectal cancer rates, especially in high-risk groups such as African Americans. However, there is a national shortage in screening capacity. Training primary care physicians (PCPs) to perform colonoscopy in this context may help to reach underserved high-risk populations.

Methods: Through an innovative program based in a medical endoscopy center in Columbia, SC, PCPs were trained to conduct colonoscopies. The center's protocol requires a two-person technique (using a trained technician), polyp search and removal during both scope insertion and withdrawal, and an onsite expert who is always available for rescue assistance (either navigational or therapeutic). Retrospective data collected from 10,958 consecutive colonoscopies performed by 51 PCPs) among 9,815 patients (October 2002 to November 2007) were used to calculate rates of cecal intubation, detection of total polyps, adenomas, advanced neoplasia, cancer, adverse events, and times of endoscope insertion and withdrawal (Quality Study). Also, we compared colonoscopy screening compliance rates and computed adjusted odds ratios for the above outcomes among colonoscopy-eligible patients of trained AA PCPs (study group) vs. untrained PCPs (comparison group), before and after initiating colonoscopy training (Compliance Study). Retrospective chart review was conducted on 200 consecutive, established outpatients aged ≥50 years at each of 12 PCP offices (7 trained AA PCPs and 5 untrained PCPs, practicing in the same geographic region); for a total of 1,244 study group and 923 comparison group patients. Additionally, we evaluated a smaller state-supported colon cancer screening program (n=665) by comparing adenoma detection rates and other colonoscopy parameters among PCPs and other providers, including an examination of rates among African-American (AA) participants &lt;45 years of age.

Results: Of the 51 PCPs in the Quality Study 15 were AA. Mean patient age in this screening group was 58.3 (±10.9) years, 48.0% were male, and 48.1% were AA. The cecal intubation rate was 98.1%, polyp detection rate 63.1%, hyperplastic polyp 27.5%, adenoma 29.9%, advanced neoplasia 5.7%, cancer 0.63%, major adverse events 0.06% (including 2 perforations; no death). Mean (±SD) insertion and withdrawal times were 14.4 (±9.3) and 10.9 (±6.8) minutes, respectively; 13.2 (±8.6) and 8.0 (±4.5) minutes without polyps found, and 15.1 (±9.6) and 12.5 (±7.3) minutes when ≥1 polyp was found. In the Compliance Study, we found that post-training colonoscopy rates in both groups were higher than pre-training rates: 48.3% vs. 9.3% in the study group, 29.6% vs. 9.8% in the comparison group (both p&lt;0.001). AA patients in the study group showed over 5-fold increase in colonoscopy compliance (8.9% pre-training vs. 52.8% post training), with no change among Whites (18.2% vs. 25.0%). After adjusting for demographic factors, duration since becoming the PCP's patient, and health insurance, the study group had a 66% higher likelihood of colonoscopy in the post-training period (OR=1.66; CI, 1.30, 2.13), and AAs had a five-fold increased likelihood of colonoscopy relative to Whites. Results from the state-supported colon cancer screening program showed virtually identical screening rates for the PCPs, and virtually identical cancer reduction potential (based on the adenoma detection rate or ADR) among African-American participants 45-50 years of age as in older individuals.

Conclusions: In the largest published study of PCP-performed colonoscopies with standby specialist support we observed performance quality indicators and lesion detection rates that were comparable to documented rates among experienced gastroenterologists. We also observed that screening-eligible AA patients of AA physicians are much more likely to be screened after their PCP has been trained, and these results are broadly applicable to AAs as young as 45 years of age; and thus support the ACG recommendation for earlier screening in this population. Because of the increased virulence of these very preventable cancers in African Americans, these results have very important public health and public policy implications.

Funding: This work was supported by four grants from the National Cancer Institute: U01 CA114601 from the Center to Reduce Cancer Health Disparities (Community Networks Program) to the South Carolina Cancer Disparities Community Network (SCCDCN); 3U01 CA114601-02S4  to S Xirasagar (Project Leader) and JR Hébert (P.I./Mentor) to study the Impact of Colonoscopies Performed by Primary Care Physicians; K05 CA136975, an Established Investigator Award in Cancer Prevention and Control from the Cancer Training Branch of the National Cancer Institute to JR Hébert; and 1R15CA156098-01 to S. Xirasagar. Funding also was provided by the South Carolina Department of Health and Environmental Control (Contract No: CY-11-032) and by the University of South Carolina Office of Research.

Citation Format: James R. Hebert, Sudha Xirasagar, Thomas G. Hurley, James B. Burch. Community-based interventions to reduce for colon cancer disparites in African Americans in South Carolina. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr FO02-01.