Background and Study Rationale: More than one million people in the U.S. are living as colorectal cancer (CRC) survivors. Post-treatment risk of recurrence is a significant clinical problem and is compounded by evidence of low prevalence of surveillance, notably among African Americans (AA). In national samples (Rolnick et al. 2005; Lafata et al. 2008), AA are significantly less likely than European Americans (EA) to receive surveillance colonoscopy at guideline-recommended intervals, which likely contributes to disparities in CRC mortality rates. In 2007, U.S. age-adjusted CRC mortality rates were 19.5 for EA males, 29.1 for AA males, 13.7 for EA females, and 19.7 for AA females.

The efficacy of surveillance colonoscopy has been well documented and it is the first-choice procedure for clinical surveillance after curative-intent CRC resection. CRC surveillance adherence is particularly important for AA, who tend to present at initial diagnosis with larger tumor size than EA, and who may be at greater risk of CRC recurrence. The purpose of this study was to examine whether the disparities in CRC surveillance seen nationally are present in South Carolina (SC).

Methods: Statewide, population-based data from the SC Hospital Billing Data database for calendar year 2007 were used to examine whether racial differences were present in surveillance colonoscopy receipt after CRC resection. Unique IDs were used to track patients over time. ICD-9 diagnosis and procedure codes, race, and gender and were used to identify and categorize patients who received resection surgery and colonoscopy following resection at 1 year, 2 years, and 3 years post-resection. The Chi-square test was used to test for differences in receipt of surveillance colonoscopy based on race and gender by follow-up year.

Results: Data from 1,273 (914 EA and 359 AA) patients diagnosed with Stage I–II CRC who received CRC resection in 2007 were evaluated. Significant racial differences in receipt of surveillance colonoscopy were seen. At 1 year post-resection, 25.6% of EA (n=234) and 18.1% of AA (n=65) had surveillance colonoscopy (p=0.005); at 2 years post-resection, 46.8% of EA (n=428) and 39.6% of AA (n=142) received surveillance colonoscopy (p=0.019); and at 3 years post-resection, 50.2% of EA (n=459) and 44.8% of AA (n=161) underwent surveillance (p=0.084).

Among females, 25.0% of EA (n=114) compared with 18.2% of AA (n=37) received CRC surveillance at 1 year post-resection (p=0.056); at 2 years post-resection, 45.8% of EA (n=209) and 37.9% of AA (n=77) had surveillance colonoscopy (p=0.058); and at 3 years post-resection, 49.1% of EA females (n=224) compared with 43.3% of AA (n=88) underwent surveillance (p=0.171).

Among males, the only statistically significant finding was at 1 year post-resection; 26.2% of EA (n=120) compared with 17.9% of AA (n=28) received CRC surveillance at 1 year post-resection (p=0.037); at 2 years post-resection, 47.8% of EA (n=219) and 41.7% of AA (n=65) had surveillance colonoscopy (p=0.183); and at 3 years post-resection, 51.3% of EA (n=235) compared with 46.8% of AA (n=73) underwent surveillance (p=0.330).

Conclusions: Reflecting national data, surveillance colonoscopy rates are low in SC. Rates are substantially lower among AA than among EA and are lower for AA men than for EA men at 1 year post-resection, emphasizing the need for culturally appropriate surveillance plans. While a study limitation is that some patients may have received colonoscopies at sites that did not report their data to the registry, it is clear that not only are there racial and gender disparities in CRC surveillance colonoscopy but rates are suboptimal for both EA and AA. These results will guide the development of targeted multi-level intervention strategies and messages to improve CRC surveillance adherence to optimize survivorship and improve quality of life.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A55.