Molecular stool testing for colorectal cancer surveillance

Since January 2014 the Dutch screening programme for bowel cancer has been implemented. Screening will increase the demand for surveillance. Although patients in whom adenomas have been removed are at increased risk of progressing to cancer, solid evidence on the reduction of death from CRC through the current colonoscopy-based surveillance is lacking. Furthermore, colonoscopy-based surveillance leads to high logistic demands, high individual burden and high costs. Therefore, there is need for new surveillance strategies. Stool-based molecular testing (Cologuard®, consisting of a stool DNA test and an immunochemical assay for human hemoglobin) or Faecal Immunochemical Testing (FIT) may serve as an alternative for colonoscopy surveillance.

Objectives: 1. To compare the accuracy of an established molecular stool test (Cologuard®) and FIT to colonoscopy for detection of advanced adenomas or CRC (advanced neoplasia) in a surveillance population.

2. To model various strategies of stool-based molecular surveillance to inform health policy decisions.
Study design: Prospective observational cross-sectional cohort study.

Study population: Persons with a scheduled surveillance colonoscopy (age 50-75 year) in one of the participating centers.

Intervention: Collection of whole-stool samples for stool testing primary to surveillance colonoscopy and the completion of a questionnaire.

Main study parameters/endpoints:

1. The accuracy (i.e. sensitivity, specificity, positive- and negative predictive value) of the molecular stool test (Cologuard®) and FIT in the detection of advanced neoplasia compared to colonoscopy.

2. Model-based predictions of long-term health outcomes and cost-effectiveness of multiple surveillance strategies based on accuracies from endpoint 1.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Burden for participant consists of at home faeces collection, performance of FIT and the completion of a questionnaire.

Surveillance using a molecular stool test could serve as an alternative for the current method that is based on colonoscopy

In order to compare the results of the molecular stool test and FIT and subsequently model various surveillance strategies, no follow up is needed. Therefore: timepoint = 0

Collection of whole-stool samples for stool testing primary to surveillance colonoscopy and the completion of a questionnaire.