Immunochemical Fecal Occult Blood

The method of detection of colorectal cancer determined by Quebec’s colorectal cancer screening program (Programme québécois de dépistage du cancer colorectal – PQDCCR) is the immunochemical fecal occult blood test (iFOBT). INESSS was asked to propose a positivity threshold for the immunochemical fecal occult blood test (iFOBT) in the upcoming screening phase (Phase II) of the demonstration projects under Québec’s colorectal cancer screening program.

Taking into account the available scientific and contextual data and to ensure that PQDCCR managers are able to make the best use of colonoscopy resources without compromising patient safety and CRC screening benefits, INESSS has concluded that the best positivity threshold for iFOBT on a single fecal sample (per participant) is 175 ng/ml. This positivity threshold applies only to asymptomatic patients at average risk for CRC invited to participate in the PQDCCR demonstration projects. A confirmation colonoscopy will follow all positive tests reaching this threshold.

This threshold must be reviewed at the end of these projects in relation to the performances observed and the resources available.