In developed countries in the Western world, colon and rectal carcinoma (CCR) have high incidence and mortality rates. It is by far the most frequent malignant tumor of the digestive tract and is the second most frequent cause of death from malignant tumor.
Overall, around 6% of European men and 4% of women will develop CRC by age 75 years.
In Portugal, the estimated incidence of CRC is around 60/100.000 inhabitants (more than 6.500 new cases per year) and, in the last decade, there has been a significant increase in mortality rates due to CRC, currently representing the second cause of death from tumor diseases.
These data show us that CCR is an important public health problem and that it requires adequate prevention and treatment strategies.
In the case of CCR, there is yet another peculiarity: the sequence of events in carcinogenesis is a very long process. From the normal cell, through the adenoma, to the carcinoma , and invasive cancer, it can take many years, more than 7-8, in which individuals are asymptomatic but have easily detectable lesions in the intestine.
In the absence of a good strategy to carry out primary prevention, that is, measures to prevent the appearance of cancer, screening programs are the most effective way to reduce both mortality and the incidence of CCR.
More than the screening method used, it is essential to define the methodology to be applied. Generally speaking, there are two major screening strategies that can be used, opportunistic screening and systematized population-based screening, with enormous advantages for the latter.
In opportunistic screening, we are limited to offering a test to individuals who seek medical appointments or other health care. In this type of screening, we are not able to effectively control the population screened and, it is known, a large number of people make very little use of health care and systematically escape the programme.
In a population-based screening, at the outset, a coordinating entity, the target population and the forms of convocation are defined. This type of screening is the only one that guarantees equal access to all eligible individuals and allows for the measurement of results and adequacy of methodologies.
More than the screening method used, it is essential that screening be carried out in an organized and continuous way. The two methods, accepted and validated in population-based screenings, are fecal occult blood test (PSOF), followed by colonoscopy in positive cases and direct colonoscopy.
In the case of PSOF, this should be performed annually or biannually and, in the case of direct colonoscopy, every 5 or 10 years.
Both methods have advantages and disadvantages: simplicity of execution, ease of implementation, absence of adverse effects, and initial costs are in favor of PSOF, diagnostic accuracy, methodological simplification, and overall costs in favor of colonoscopy.
But it is not, at all, the aim of the article to choose a preferred method for carrying out CCR screening. What is important to emphasize is that both reduce mortality and the incidence of CRC and are cost-effective.
In Portugal, within the scope of the National Program for Oncological Diseases, the Directorate-General for Health recognizes the importance of this topic and places it as a pressing need, due to the morbidity and mortality associated with these neoplasms, knowing that the programs of screening have a significant impact on reducing incidence and mortality.
This need has also been assumed at the European level, where a primary test with fecal occult blood testing is recommended in the asymptomatic population aged between 50 and 74 years and without other risk factors.
In this strategy, patients with positive occult blood tests are proposed to undergo colonoscopy.
In 2017, legislation was finally published that prioritizes organized population-based screening for the following malignancies: CCR, female breast and cervix.
The proposed strategy follows the European recommendation, with PSOF being performed every two years for the asymptomatic population between 50 and 75 years of age, followed by colonoscopy in positive cases.
It is now up to the different health structures, including the Regional Health Administrations and Hospital Centers, to implement this strategy. This is what should be the aim of healthcare structures in the Algarve region.
Between 2018 and 2020, the pilot program started in the region, allowing to track around 25.000 users with PSOF and to carry out 500 colonoscopies. However, the emergence of the COVID pandemic interrupted the development of the program. It is urgent, now, to start over!
Finally, and perhaps the most important message, we must remember that the success of a screening program depends, more than anything, on the adherence of the population or, in other words, the most complete and infallible method is of little use if people do not do it.
This desideratum, achieving adherence by the population depends on knowledge, awareness of the problem and it is up to us, health professionals, to know how to transmit and inform it.
CCR is a frequent and serious disease. CCR can kill. But, at the same time, it is a preventable disease and, very important, we have a long period of time to do so. It's just up to us and we want to get it.
Author Paulo Caldeira is a Gastroenterologist, is a member of the CHUA Rectal Cancer Reference Center and is the Director of the CHUA Gastroenterology Service
Note: Second in a series of articles that the Sul Informação will publish in the coming months, in partnership with the CHUA Rectal Cancer Reference Center, in order to contribute to increasing health literacy, specifically on issues related to CCR.
Comments