New test may improve colorectal cancer screening

A newly developed test that appears to detect colorectal cancer precursors better than the current test may improve population-based screening.

Population-based screening is a common approach for colorectal cancer due as early detection can provide better outcomes for patients.

The majority of current population-wide screening programmes use the fecal immunochemical test (FIT), which is a stool test that measures the presence of the blood protein hemoglobin.

These programmes have been proven to be successful in diagnosing colorectal cancer at earlier stages and reducing colorectal cancer mortality.

Now, a study published in The Lancet Oncology and led by the Netherlands Cancer Institute compared a new test – the multitargetFIT-test (mtFIT) which measures hemoglobin and two additional proteins – with the current tests in over 13,000 participants of the Dutch national population-based screening programme.

Gerrit Meijer, principle investigator at the Netherlands Cancer Institute stated: “The current test performs well, but leaves room for improvement. We want to be able to detect the tumors before they have become invasive, that is at the stage of larger premalignant polyps. Treating physicians then can remove these polyps during a colonoscopy, rather than by surgery.”

“The new test can detect cancer precursors more effectively.

“Our results predict that the test can reduce the number of new cases of colorectal cancer and mortality resulting from it.”

According to the researchers, the new test is just as easy to use as the current test and yielded more positive results than the current test.

While this led to more colonoscopies, with the new mtFIT test doctors found abnormalities in 299 persons, compared to 159 persons with the current FIT test.

Meijer stated: “The new test detects more larger polyps without a significant increase in ‘false-positive’ results and thus unnecessary colonoscopies.”

The exact number of colorectal cancer cases that could be prevented with this new test depends on the way the current FIT test is used in different countries.

“The Dutch screening programme applies a relatively high cutoff value to consider the FIT test positive, meaning unfavorable,” added Meijer.

“Here, the new mtFIT test could lead to 21% fewer cases of colorectal cancer and 18% fewer mortalities. In countries that already use a lower FIT cutoff value these figures would be lower, but likely at least 5% fewer people would develop colorectal cancer, with at least 4% fewer mortalities. In both scenarios, the new test could be cost-effective.”

Implementation of mtFIT in existing FIT-based screening programs will be relatively easy because both tests basically require the same screening logistics.

“This is exceptionally good news,” says Meijer. “The critical next step is to produce the test at an industrial scale according to European diagnostic test guidelines. To this end we founded the company CRCbioscreen, to enable the test to benefit CRC screening participants in the Netherlands and beyond.”