Barcelona researchers come up with method to improve colon cancer screening

Colon cancer is the most frequent form of cancer in Spain and the second cause of death around the world. But now researchers at a Barcelona institute have come up with a screening method that improves the prevention and detection of the disease.

Researchers from the IDIBAPS biomedical institute have shown that identifying certain tiny molecules of RNA (microRNAs) in feces samples allows the precursors of tumors and lesions, known as polyps, to be more precisely detected than in current blood tests.

According to a study published in the 'Gastroenterology' journal, the new method raises precision in diagnosing tumors to almost 96%, and the researchers also show that it can improve the detection of polyps and reduce the need for colonoscopies by 35%. 

"The current method is effective and allows for reducing deaths from colon cancer and lowers the incidence rate. But we also know, as with other methods, that it's not perfect. Our project tries to solve the limitations and be more sensitive and specific in avoiding unnecessary colonoscopies," says the medical director of Hospital Clínic and one of the study's coordinators, Doctor Antoni Castells.

Making cancer screening more effective 

This is the strategy the IDIBAPS' researchers propose: adding the analysis of the identified microRNAs as a biomarker in the fecal occult blood test to improve the effectiveness of screening programs for colon and rectal cancer, which are effective but can be improved.

The colon cancer screening program is addressed to men and women over 50, who receive an informative letter at home advising them to take a fecal occult blood test, which checks stool samples for hidden, or occult, blood every two years.

The researchers say the method they have developed raises precision in diagnosing the cancer from today's 70% to almost 96%. As for polyps, the current blood test detects between 20% and 25%, while the new method raises that to up to 60%.

The people who take part in the colon cancer screening program will have to do the same fecal occult blood test as now and using the same kit. It is in the laboratory where things will change, where the microRNAs will also be analyzed.

A preventable disease

In many cases, colon cancer can be prevented, given that the tumor is preceded by a polyp that can be removed if detected, preventing the illness from developing. This makes screening programs an effective tool for detecting early tumors and for preventing them. 

The results from the current colon cancer screening program have been positive, reducing deaths from this type of cancer by 9% in many autonomous communities like Catalonia, which has been running the program since 2010.