Non-invasive tests to detect colorectal cancer a success
Barcelona’s Hospital Clínic and the University Hospital of the Canary Islands have coordinated the first study in the world to compare the two strategies to detect this disease.
Barcelona’s Hospital Clínic and the University Hospital Complex of the Canary Islands have coordinated the first study in the world to compare the two methods accepted by the international scientific community for early detection of colon and rectal cancer: fecal occult blood test (European model) and direct exam of the inside of the colon using colonoscopy (American model). Both are effective for detecting cancer and precursor lesions (adenomatous polyps).
The study was led by Dr. Antoni Castells, director of the Hospital Clínic Institute for Digestive Diseases and coordinator of the Barcelona Program for Early Detection of Colon and Rectal Cancer, and Dr. Enrique Quintero, head of the Digestive System Service at the University Hospital Complex of the Canary Islands.
A total of 60,000 people from eight Spanish autonomous communities, including Catalonia, participated in this research study carried out by the Hospital Clinic and University Hospital of the Canary Islands over four years. The study was co-funded by the Carlos III Institute of Health in Madrid and the Spanish Association Against Cancer (AECC).
The results of this study have been published in The New England Journal of Medicine. The first conclusion is that more fecal occult blood tests (34%) were carried out than colonoscopies (25%). The number of cases of cancer detected with each method was the same and most were in the early stages of development. The complications observed were minimal in both groups, although lower in those patients that received fecal occult blood tests. Furthermore, of the 60,000 patients, 1,600 requested they be changed from the colonoscopy (which must be done every 10 years) to the fecal occult blood test (a non-invasive test that must be done every two years).
"Current detection methods in fecal samples are so sensitive that they detect the same cancers we would find using a colonoscopy and more than half of the precursor lesions in a single test," said Dr. Quintero.
One in 20 people will suffer from colon or rectal cancer in their lifetime. This disease, if detected early, is easy to treat and has a very high survival rate.
"The final goal of our research is to discover the benefits of each test regarding patient survival rates, an effect we will only be able to judge ten years from now, after the study has finished," said Dr. Castells.
Early detection programs in Spain
In Spain, colorectal cancer is the third most common type in men (after lung and prostate) and the second most common among women (after breast cancer), according to data from the AECC. Each year, approximately 28,000 new cases are diagnosed. Most of these are in patients between 65 and 75 years old, although they are also found in the 35-to-40-year-old age bracket. Cases that appear at an earlier age are often due to a patient’s genetic predisposition.
Nine autonomous communities –Catalonia, Valencia, Murcia, Canary Islands, Basque Country, Cantabria, Extremadura, Castile and Leon, and La Rioja– have screening programs geared towards the target population to detect colon cancer early and prevent it. This type of tumor normally causes no discomfort until it is in the very advanced stages, which is why it is important to do preventative screening in patients without symptoms. A healthy lifestyle is also advisable, avoiding excess alcohol, not smoking, exercising regularly and eating a healthy diet.
For more information, see the AECC press release.