Colorectal Cancer
Conditions
Keywords
Colorectal cancer, Screening, Average-risk population, faecal occult blood tests
Brief summary
Colorectal cancer screening by faecal occult blood test (FOBT) is a high public health priority. The interest of guaiac tests (G-FOBT) is limited by their poor sensitivity, while the superiority of I-FOBT in comparison with G-FOBT is now established. Nevertheless automated quantitative I-FOBTs have not been compared, and the optimal number of samples and threshold is not yet fixed. The aim of this study is to compare the performances of the 2 more well-known I-FOBTs with automated analyzers (magstream by Fujirebio, and OC Sensor by Eiken) for different positivity thresholds and numbers of samples in general average risk population. Patients will performed a two samples Magstream, a two samples OC Sensor and Hemoccult II. In case of a positive test, a colonoscopy will be performed. Sensitivity and specificity for detection of cancer and advanced neoplasias will be compared between tests using ratio of sensitivities (RSN) and ratio of false positives (RFP) according to number of samples and positivity threshold.
Interventions
OTHERColonoscopy
Colonoscopy if at least one of the faecal occult blood tests is positive (blinded to each test result)
Sponsors
National Cancer Institute, France
Ligue contre le cancer, France
University Hospital, Caen
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SCREENING
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
50 Years to 74 Years
Healthy volunteers
No
Inclusion criteria
* 50 to 74 years * Informed consent signed
Exclusion criteria
* Recent digestive symptoms * Complete colonoscopy less than 5 years ago * Personal history of colorectal cancer or colorectal adenoma or colonic disease requiring regular colonoscopy surveillance * Familial history of colorectal cancer in a first degree next of kin before 65 years, or two cases in first degree next of kin. * Severe extra-intestinal disease * Screening ill-timed (ex. depression)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ratio of sensitivities (RSN) for detection of advanced neoplasias | Up to 6 months after faecal occult blood test (FOBT) (At the time of colonoscopy) | Advanced neoplasias included invasive cancers and high-risk adenomas (larger than 1 cm or with high grade dysplasia). RSN is the ratio of the true positives of two tests. True positives for one test are patients positive for the test, with targeted lesion (here advanced neoplasias). RSN will be calculed between immunochemical tests, and for each immunochemical test in reference to gaiac test. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| RFP for detection of advanced neoplasias | Up to 6 months after FOBT (At the time of colonoscopy) | RFP is related to specificity. False positives of one test are patients with a positive test but without targeted lesions (here advanced neoplasias). RFP will be calculed between immunochemical tests, and for each immunochemical test in reference to gaiac test. |
| Relative Receiver Operating Characteristics(ROC) curves | Up to 6 months after FOBT (At the time of colonoscopy) | Relative ROC curves plots RSN according to RFP (similar to ROC curve). Relative ROC curves will be compared in reference to gaiac test, according to number of samples analysed for each immunochemical test, and the way they are analysed. |
| Detection rate of invasive cancer | Up to 6 months after FOBT (At the time of colonoscopy) | — |
| Detection rate of advanced neoplasias | Up to 6 months after FOBT (At the time of colonoscopy) | — |
| Ratio of False Positives (RFP) for detection of invasive cancers | Up to 6 months after FOBT (At the time of colonoscopy) | RFP is related to specificity. False positives of one test are patients with a positive test but without targeted lesions (here invasive cancers). RFP will be calculed between immunochemical tests, and for each immunochemical test in reference to gaiac test. |
| Predictive positive value for detection of invasive cancers | Up to 6 months after FOBT (At the time of colonoscopy) | — |
| Predictive value for detection of advanced neoplasias | Up to 6 months after FOBT (At the time of colonoscopy) | — |
| Positivity rate | Immediate (At the time of FOBT) | — |
| Cost-effectiveness analysis | Up to 6 months after FOBT (At the time of colonoscopy) | It will take into account number of samples and threshold |
Countries
France
Outcome results
None listed