Of the colorectal tumors that are detected during a screening examination, many are still at an early stage and are readily treatable. Not only can colonoscopy detect colorectal cancer, but polyps can be removed immediately. Therefore, in some cases, a screening colonoscopy can prevent colorectal cancer from developing in the first place. The results of a prospective long-term study support the high benefit of colonoscopy for screening purposes.
The intestine fulfills various vital functions, such as the absorption of nutrients from food, which are subsequently channeled into the bloodstream. In addition, the intestinal flora consists of billions of microorganisms that are significantly involved in the function of the intestine-associated immune system. Many people suffer from gastrointestinal complaints. In most cases, these are harmless, but not always. Colorectal cancer is the third most common cancer in Switzerland [1]. Malignant intestinal tumors occur mainly as colorectal carcinoma (cancer of the colon and rectum), and less frequently as anal carcinoma or malignant tumor of the small intestine. Colorectal carcinoma develops over a period of years from precancerous lesions that can be detected and immediately removed during colonoscopy [2]. The risk of developing colorectal cancer increases with age. Colonoscopy is recommended from the age of 50 years, possibly earlier if there is a family history of colorectal cancer [3].
Colonoscopy is considered the gold standard for colorectal cancer screening
Symptoms for which a colonoscopy should usually be performed are, for example, blood in the stool or an unclear weight loss. Colonoscopy may also be useful for other complaints such as changes in bowel habits or unexplained abdominal pain [3]. Colonoscopy is generally considered the gold standard for colorectal cancer screening because it visualizes the entire colon and neoplasms can be removed directly [4].
Cohort study provides impressive evidence of preventive benefits
Epidemiologists at the German Cancer Research Center (DFKZ) evaluated data from more than 9000 participants as part of the ESTHER* study (box). [2,5]. Study participants were interviewed at regular intervals about their health and lifestyle, and their treatment and cancer registry data were recorded. After an observation period of approximately 17 years, 268 cases of colorectal cancer had occurred among the study participants, and 98 participants had died of colorectal cancer. Those ESTHER participants who had taken advantage of a screening colonoscopy had a 60 percent lower risk of a colorectal cancer diagnosis than study participants who had not taken advantage of the screening offer. The risk of dying from colorectal cancer was as much as 75 percent lower in the screening group in the 10 years after colonoscopy.
* Epidemiological studyon opportunities for prevention, early detection and optimized THerapy ofchronic ERdiseases.
Implement early detection masses broadly
“The participants in our study represent a cross-section of the population. They use the normal screening services offered in their region and are not examined in special centers. Therefore, we can now quantify for the first time in a long-term study from Germany what contribution screening colonoscopy makes to cancer prevention in real life,” explains Prof. Dr. Hermann Brenner, Deputy Director, Division of Clinical Epidemiology and Aging Research, DKFZ [2]. To date, there have been very few studies on this subject worldwide, and almost all of them originated in the USA, where colonoscopy had already been used on a larger scale. Prof. Brenner summarizes the conclusion of the study as follows: “Our results quantify the enormous contribution that screening colonoscopy can make to cancer prevention. But the best screening examination is of little use if it is not sufficiently taken advantage of. Almost 25,000 people still die of colorectal cancer in Germany every year. Most of these deaths would be preventable through colorectal cancer screening. We still need to find ways to motivate more people to use the potentially life-saving screening examinations for colorectal cancer” [2]. In Switzerland, mandatory health insurance covers the costs of colorectal cancer screening in individuals aged 50 to 69 years. Payment is made for a “blood-in-stool test” every two years or a colonoscopy every ten years [6]. “In cantons that do not have organized screening programs, however, screening is not exempt from the deductible” regrets Guido Biscontin, specialist in early detection at the Swiss Cancer League [7]. Experts aim to increase the age limit from 69 to 74 years, which means that the compulsory health insurance would have to cover the costs of screening examinations until the age of 75 [7]. This would bring Switzerland in line with international recommendations.
Literature:
- swiss cancer screening, www.swisscancerscreening.ch/krebs-frueherkennung/darm/fakten-zu-darmkrebs, (last accessed May 13, 2022).
- “70 percent fewer colorectal cancer deaths after screening colonoscopy,” German Cancer Research Center, Feb. 26, 2021.
- “At what age is a colonoscopy useful?”, Luzerner Kantonsspital, 02.01.2022.
- Guo F: Effects of colorectal cancer screening on colorectal cancer incidence and mortality in Germany, https://archiv.ub.uni-heidelberg.de/volltextserver/30430/1/Guo_Fen.pdf (last accessed May 13, 2022).
- Guo F, et al: Strong reduction of colorectal cancer incidence and mortality after screening colonoscopy: prospective cohort study from Germany. The American Journal of Gastroenterology 2021, DOI: 10.14309/ajg.00000000001146.
- Krebsliga Schweiz, www.krebsliga.ch/beratung-unterstuetzung/praevention-und-frueherkennung/frueherkennung/darmkrebs/darmkrebs-screening-programm (last accessed 13.05.2022)
- “What is missing for systematic colorectal cancer screening in Switzerland?” Swiss Cancer League, 01.03.2022
HAUSARZT PRAXIS 2022; 17(6): 20
InFo ONCOLOGY & HEMATOLOGY 2022; 10(3): 32.
