Cristina Nichita

Training primary care physicians to offer their patients faecal occult blood testing and colonoscopy for colorectal cancer screening on an equal basis: a pilot intervention with before–after and parallel group surveys

Objectives Primary care physicians (PCPs) should prescribe faecal immunochemical testing (FIT) or colonoscopy for colorectal cancer screening based on their patients values and preferences. However, there are wide variations between PCPs in the screening method prescribed. The objective was to assess the impact of an educational intervention on PCPs’ intent to offer FIT or colonoscopy on an equal basis. Design Survey before and after training seminars, with a parallel comparison through a mailed survey to PCPs not attending the training seminars. Setting All PCPs in the canton of Vaud, Switzerland. Participants Of 592 eligible PCPs, 133 (22%) attended a seminar and 106 (80%) filled both surveys. 109 (24%) PCPs who did not attend the seminars returned the mailed survey. Intervention A 2 h-long interactive seminar targeting PCP knowledge, skills and attitudes regarding offering a choice of colorectal cancer (CRC) screening options. Outcome measures The primary outcome was PCP intention of having their patients screened with FIT and colonoscopy in equal proportions (between 40% and 60% each). Secondary outcomes were the perceived role of PCPs in screening decisions (from paternalistic to informed decision-making) and correct answer to a clinical vignette. Results Before the seminars, 8% of PCPs reported that they had equal proportions of their patients screened for CRC by FIT and colonoscopy; after the seminar, 33% foresaw having their patients screened in equal proportions (p<0.001). Among those not attending, there was no change (13% vs 14%, p=0.8). Of those attending, there was no change in their perceived role in screening decisions, while the proportion responding correctly to a clinical vignette increased (88–99%, p<0.001). Conclusions An interactive training seminar increased the proportion of physicians with the intention to prescribe FIT and colonoscopy in equal proportions.

Development and Clinical Validation of a Blood Test Based on 29-Gene Expression for Early Detection of Colorectal Cancer.

Purpose: A blood test for early detection of colorectal cancer is a valuable tool for testing asymptomatic individuals and reducing colorectal cancer–related mortality. The objective of this study was to develop and validate a novel blood test able to differentiate patients with colorectal cancer and adenomatous polyps (AP) from individuals with a negative colonoscopy. Experimental Design: A case–control, multicenter clinical study was designed to collect blood samples from patients referred for colonoscopy or surgery. Predictive algorithms were developed on 75 controls, 61 large AP (LAP) ≥1 cm, and 45 colorectal cancer cases and independently validated on 74 controls, 42 LAP, and 52 colorectal cancer cases (23 stages I–II) as well as on 245 cases including other colorectal findings and diseases other than colorectal cancer. The test is based on a 29-gene panel expressed in peripheral blood mononuclear cells alone or in combination with established plasma tumor markers. Results: The 29-gene algorithm detected colorectal cancer and LAP with a sensitivity of 79.5% and 55.4%, respectively, with 90.0% specificity. Combination with the protein tumor markers carcinoembryonic antigen (CEA) and CYFRA21-2 resulted in a specificity increase (92.2%) with a sensitivity for colorectal cancer and LAP detection of 78.1% and 52.3%, respectively. Conclusions: We report the validation of a novel blood test, Colox®, for the detection of colorectal cancer and LAP based on a 29-gene panel and the CEA and CYFRA21-1 plasma biomarkers. The performance and convenience of this routine blood test provide physicians a useful tool to test average-risk individuals unwilling to undergo upfront colonoscopy. Clin Cancer Res; 22(18); 4604–11. ©2016 AACR.

S1136 A New Blood-Based Screening Test for Colorectal Cancer: A Pilot Study

Background: Colonoscopy is considered to be the standard of care for the diagnosis of colorectal cancer. However, population-based studies have reported a subset of patients with cancer who do not undergo colonoscopy. The purpose of this study was to estimate the prevalence and identify the predictors of not having a colonoscopy in the period preceding colorectal cancer diagnosis. Methods: Using the population-based SEER registries, we identified patients aged >= 69 with colorectal cancer diagnosed from 1994-2005. Linked inpatient and outpatientMedicare claimswere used to identify receipt of colonoscopy prior to diagnosis. We divided this group into patients who had did not have colonoscopy within 3 years of diagnosis (Group I) and those who had 1 or more colonoscopies from 6 months prior to 30 days after diagnosis (Group II). Patient, sociodemographic and tumor factors were used to identify predictors of not having colonoscopy in univariate and multivariable logistic regression analysis. Results: We identified 79,032 patients, including 19.6% in Group I and 80.4% in Group II. Among patients in Group I, 31.6% had barium enema, 21.4% had flexible sigmoidoscopy and 57.3% underwent CT scan within 6 months prior to and 30 days after diagnosis. Independent predictors of Group I included age > 85, African American race, non-married, nursing home residence, rural residence, lower comorbidity score, diagnosis before 2000, AJCC Stage II-IV, left sided or rectal tumor site, and emergency presentation. Patients without colonoscopy were also less likely to undergo surgical resection (OR 0.55, CI 0.52-0.59). In a Cox proportional hazards model that adjusted for demographics, stage and treatment, not undergoing colonoscopy was associated with a higher risk of death (HR 1.31, CI 1.28-1.33). Conclusions: In this large, population based analysis, almost 20% of newly diagnosed colorectal cancer patients did not undergo colonoscopy at the time of diagnosis. Although these patients were more likely to be elderly with advanced disease, lack of colonoscopy appears to be an indicator of emergency presentation, less aggressive treatment and poorer prognosis.