Popular Fecal Immunochemical Tests Equally Effective for Detecting Colorectal Cancer

New York (Reuters Health) - Two widely used fecal immunochemical tests show no significant difference in their ability to detect colorectal cancer (CRC) and advanced neoplasia, according to new findings from the Netherlands.

The study, conducted within the Dutch national CRC-screening program, found that the FOB-Gold (Sentinel Diagnostics, Italy) and the OC-Sensor (Eiken Chemical, Japan) have similar accuracy in detecting advanced neoplasia and CRC at a positivity cut-off level of 15 mcg Hb/g feces or more.

Given this, the authors concluded, "other features can now guide informed decision making when selecting one of these two brands for FIT-based CRC screening."

One of the most important considerations is the test's ease of use and how that affects the participation rate, based on the principle that "The best test is the one that gets done well," they note in Gastroenterology, online July 25.

This is the largest population-based study to compare these two FITs in a single bowel movement of a participant, corresponding author Dr. Manon C.W. Spaander of Erasmus MC University Medical Center in Rotterdam told Reuters Health by email.

The study's target population was first-time invitees into the national CRC-screening program, ages 59 to 75. Of a random sample of more than 42,000, 22,064 participated in the study, and 21,078 completed both FITs in a single bowel movement.

All 2,112 patients (9.6%) with one or two positive FIT results were invited for a pre-colonoscopy interview, and 1,778 of these (84%) underwent a colonoscopy. In that group, advanced neoplasia was detected in 716 (4%), and CRC was detected in 82 (0.5%).

Advanced neoplasia was detected after a positive FOB-Gold in 610 (1.45%) of total invitees and in 606 (1.44%) after a positive OC-Sensor, a non-significant difference. CRC was detected after a positive FOB-Gold result in 74 invitees (0.18%) and after a positive OC-Sensor result in 78 (0.18%).

Among participants who completed both FITs, the positivity rate was 7.5% for FOB-Gold versus 7.7% for OC-Sensor (P=0.14).

Fifty-seven percent of the participants had two positive FITs, 20% had a positive FOB-Gold and negative OC-Sensor, and 23% had a negative FOB-Gold and positive OC-Sensor.

"The effectiveness of a screening program is influenced by many factors," of which the test is just one, Dr. Spaander said.

Of the two tests, only the OC-Sensor is currently available in the United States, Dr. Jeffrey Lee of Kaiser Permanente Medical Group, in San Francisco, told Reuters Health by email. He was one of the authors of 2017 U.S. recommendations on FIT in screening for colorectal neoplasia.

Dr. Lee agreed that multiple major factors have to go into choosing a FIT, including "whether the test has been rigorously tested in a screening population, its accuracy for colorectal cancer and serious pre-cancerous polyps, and its uptake in the screening population (i.e., is the test easy to use and do people complete the test)."

Another important factor is sample stability. "Some healthcare systems allow FITs to be mailed back to the laboratory for analysis and there are certain areas in the United States that deal with extreme heat, which could impact the sample stability," Dr. Lee said.

Overall, he concluded, "This study does help in providing information such as test accuracy for colorectal cancer and serious pre-cancerous polyps in a screening population."

The Dutch Ministry of Health funded the study, and the authors declared no conflicts of interest.—Scott Baltic

SOURCE: https://bit.ly/2LwOXPC

Gastroenterology 2018.

(c) Copyright Thomson Reuters 2018.