Fecal Immunochemical Test Samples Are Good for 10 Days

The fecal immunochemical test has become the preferred stool-based method of screening for colorectal cancer. However, delays can occur between stool sample collection and return to the laboratory. This raises the clinical question: How long are the samples free from deterioration and usable for testing?

To answer this question, investigators evaluated fecal immunochemical tests of 8958 residents of the Netherlands (mean age, 61). Patients were grouped according to the time between collection and return of the sample: ≤2, 3, 4, 5, 6, or ≥7 days. Among these groups, the percentages of positive tests were similar (range, 7.7%–9.0%). Investigators stored a random sample of 71 positive stool samples at room temperature and retested them every 3 …