Computed Tomography Colonography vs Colonoscopy for Colorectal Cancer Surveillance After Surgery.

BACKGROUND & AIMS: Recommendations for surveillance after curative surgery for colorectal cancer (CRC) include a 1-year post-resection abdominal-pelvic computed tomography (CT) scan and optical colonoscopy (OC). CT colonography (CTC), when used in CRC screening, effectively identifies colorectal polyps ≥10 mm and cancers. We performed a prospective study to determine whether CTC, concurrent with CT, could substitute for OC in CRC surveillance. METHODS: Our study enrolled 231 patients with resected stage 0-III CRC, identified at 5 tertiary care academic centers. Approximately 1 year after surgery, participants underwent outpatient CTC plus CT, followed by same-day OC. CTC results were revealed after endoscopic visualization of sequential colonic segments, which were re-examined for discordant findings. The primary outcome was performance of CTC in the detection of colorectal adenomas and cancers using endoscopy as the reference standard. RESULTS: Of the 231 participants, 116 (50.2%) had polyps of any size or histology identified by OC, and 15.6% had conventional adenomas and/or serrated polyps ≥6 mm. No intra-luminal cancers were detected. CTC detected patients with polyps of ≥6 mm with 44.0% sensitivity (95% CI, 30.2-57.8) and 93.4% specificity (95% CI, 89.7-97.0). CTC detected polyps ≥10 mm with 76.9% sensitivity (95% CI, 54.0-99.8) and 89.0% specificity (95% CI, 84.8-93.1). Similar values were found when only adenomatous polyps were considered. The negative predictive value of CTC for adenomas ≥6 mm was 90.7% (95% CI, 86.7-94.5) and for adenomas ≥10 mm the negative predictive value was 98.6% (95% CI, 97.0-100). CONCLUSIONS: In a CRC surveillance population 1 year following resection, CTC was inferior to OC for detecting patients with polyps ≥6 mm. Clinical Trials.gov Registration Number: NCT02143115.

Predictors of patient uptake of colorectal cancer gene environment risk assessment.

BACKGROUND: In an ongoing clinical trial, the genetic and environmental risk assessment (GERA) blood test offers subjects information about personal colorectal cancer risk through measurement of two novel low-to-moderate risk factors. We sought to examine predictors of uptake of the GERA blood test among participants randomized to the Intervention arm. METHODS: Primary care patients aged 50 to 74 years eligible for colorectal cancer screening are randomized to receive a mailed stool blood test kit to complete at home (Control) or to the control condition plus an in-office blood test called GERA that includes assessment of red blood cell folate and DNA-testing for two MTHFR (methylenetetrahydrofolate reductase) single nucleotide polymorphisms (SNPs) (Intervention). For the present study, baseline survey data are examined in participants randomized to the Intervention. RESULTS: The first 351 intervention participants (161 African American/190 white) were identified. Overall, 249 (70.9%) completed GERA testing. Predictors of GERA uptake included race (African American race, odds ratio (OR) 0.51 (0.29 to 0.87)), and being more knowledgeable about GERA and colorectal cancer screening (OR 1.09 (1.01 to 1.18)). Being married (OR 1.81 (1.09 to 3.00)) was also significant in the multivariable model. CONCLUSIONS: Participant uptake of GERA testing was high. GERA uptake varied, however, according to socio-demographic background and knowledge.