[MUSIC] Colon cancer is a very common and lethal disease. It is the 3rd most common cancer among men with 750,000 new cases diagnosed right in 2012. And the 2nd most common cancer among women after breast cancer, with 600,000 cases diagnosed in 2012. 55% of this cancer, these cases are occurring more developed countries. And it is the second cause of cancer death worldwide. And approximately we can say that 1 out of 3 colorectal cancer patients will die of their disease. Many studies have been conducted to identify risk factors for colon cancer. And, in fact, some recent facts have been found. Between 5 to 10% of colorectal cancer patients have, actually, in mutation that give them higher risk of developing the disease, and because they inherited a syndrome, the most common syndromes are Lynch syndrome and the familial adenomatous polyposis. A higher risk of colorectal cancer is also observed among patients who have a personal history of colorectal cancer already or a personal history of polyposis. And also a higher risk among patients who suffer of some inflammatory bowel disease such as Crohn's disease, ulcerative disease. But despite the narrated syndromes give the higher risk of developing a colorectal cancer, most colorectal cancers are actually not familial but sporadic. So other risk factors are responsible for an increased risk of this disease. Among the factors that have been identified, there is obesity, there is diabetes, there is alcohol consume and lack of physical activity. Some preventive factors of being also identified and these include physical activity, use of aspirin and other non-steroidal anti-inflammatory drugs and diet rich in fruit and vegetable and fibers and poor in red meat. The rationale for colorectal cancer screening comes because, first of all, it's a very important public health problem both in developing and developed countries. And because we know that most of colorectal cancers arise from polyps that become larger and then become dysplastic and then become an immersive cancer. And this transition between polyp to the cancer is long enough to let us using some test to identify the polyps, remove them and then decrease the incidents, or identify an early cancer, remove them and then reduce mortality. And we have some tools, some tests, that are effective enough to be used as a screening test. We have tests that are called non-invasive that look for some blood in the stools. And then we have some invasive tests like sigmoidoscopy and colonoscopy, where a little, tiny camera is introduced in the large intestine and then to look for polyps and other lesions. There are other test that are becoming more popular, none of them have been, yet evaluated by randomized control trials. And among them we have the stool DNA test and the computed tomography colonography. The test that identified blood in the stool, the most studied by randomized trials, the Guaiac Faecal occult blood test, and it's been proven to reduce mortality by 14, 16%. It's a test that needs to be done at least three times in three different bowel movements. It requires a little preparation and diet in particular and of course it does not have a high sensitivity or specificity, besides all the positive testing need to be followed by a colonoscopy. And recently another faecal blood test, the faecal immunochemical test is replacing the guaiac test. Because it has a very higher sensitivity, higher specificity, it doesn't need to be done in three times, but two, it's enough. It's automated. And although it is more expensive and in fact is never been evaluated by randomized trial yet. Among the invasive test, the flexible sigmoidoscopy has been evaluated at least from four randomized control trials. And every study concluded that it reduces the incident of the diseases by 18% and it reduce mortality from the disease by 28%. The sigmoidoscopy can only detect cancer and polyps up to the splenic flexor, so missing completely the proximal colon. And it needs preparation, although less onerous than colonoscopy, and has a risk of complication of with the preparation rate of 9 out of 10,000 procedures. Then we have the colonoscopy that never been yet evaluated by randomizing clinical trials. There are actually 2 trials ongoing, but the results of these trials are expected in 2025, 2003, 4. So all the recommendation for using a colonoscopy in a screening program come mainly from the logical reasoning that, in fact, colonoscopies used as a gold standard against which all the other tests are actually compared. And some association like the American College of Gastroenterology recommends the colonoscopy as the primary test to be used in his screening program. Colonoscopy can detect polyps and cancers in both in the left and right colon. And needs and honors preparation but because of that, the polyps can be removed during the procedure. It is more expensive. It requires a high level of expertise to be done. And it has a relatively high rate of complications, in particular perforations, estimated to be 2 every 1,000 procedures. So we have a number of tests, none of them is ideal, in all the attributes that we consider for screening test. And the decision about using one or the other, it needs to be taken into account, the burden on disease, and the capacity of the place, of the reader, the country, in terms of colonoscopy and follow up treatment of the patients. We can say that during the last 20 years, a lot of screening programs have been implemented worldwide. Most of them in more developed countries which have higher burden of disease, but also which have more capacities and structures. In Europe, there are at least 16 population based organized screening that use mostly fecal occult blood test and 9 opportunistic programs that use mostly colonoscopy. In North America and Canada, fecal occult blood test is used in United States more frequently colonoscopy. There are programs also in Asia and Australia. No programs for the moment in Africa, but given the low burden of disease and many other health problems, we wonder if there is the need of programs there. The World Gastroenterology Organisation developed a sort of cascade comfort. The recommendation for countries to choose on the basis of available resources with the level 6, the level where the resources are very limited suggesting to use fecal blood test every year followed by colonoscopy for the positive ones or by barium enema work-up. So the conclusion, we have a very important public health problem which is becoming even more important also for low, and middle income countries. We have tools, tests that can be used as a screening test to reduce incidence and mortality. That choice for moving towards an implementation of colorectal cancer screening program that just need to be done, taking into account several criteria, including of course the resources, the cost, reliability, and the safety and also the patient preference. [MUSIC]
