Realizing the Full Potential of Population-Based Screening for Colorectal Cancer

Editorial to accompany the article: “Fecal occult blood tests for colorectal cancer screening in routine medical care: A longitudinal analysis from Germany” by Leon Klimeck et al. in this issue of Deutsches Ärzteblatt International

Colorectal cancer (CRC) takes many years to develop. This offers opportunities for the detection and removal of advanced precancerous lesions and early-stage cancers. Randomized trials have demonstrated the efficacy of both non-invasive triage tests such as the fecal immunochemical test (FIT) and direct visualization tests like screening colonoscopy (1). At population level, the two methods have a similar effect in terms of colorectal cancer incidence and mortality. This was shown, for instance, by a large Spanish trial (2). Correspondingly, research is now focused on how best to implement screening. Health systems should ensure that their populations can reliably access these established tests in a way that ensures high-quality, equitable care.

Use of fecal tests

In this edition, Klimeck and colleagues present their findings on the use of fecal tests (FIT since 2017) among 50- to 54-year-old women and men in Germany. They used insurance claims data for persons born between 1960 and 1968 who were continuously insured by the health insurance carrier BARMER (3). This longitudinal cohort study allowed them to describe testing patterns in an age group when only FIT was reimbursed for screening. FIT was available once each year from the primary care physician.

During the last period analyzed in this study (2019–2022), potential participants received a single information letter about this screening offer. The study describes an alarming underuse of screening tests: 55.1% of women and 22.5% of men completed at least one test over five years, and only 1.8% of women and 0.1% of men completed the tests each year as offered. This suggests significant underuse of colorectal cancer screening in this age range, particularly among men, who are at higher risk of developing colorectal cancer.

Open questions

These results raise three questions.

First, do these results accurately represent the current status of colorectal cancer screening among 50- to 54-year-olds in Germany? In all probability they do. The methodology appears robust, as the data for both screening and diagnostic FIT and colonoscopy were traced back for 10 years. Only 6.7% of the target population (68 189 persons) were excluded from participation in the study because of a recent colonoscopy. Opportunistic colonoscopies do not explain this result. While 53% of those in the initial sample were excluded because of non-continuous insurance coverage, these persons would most likely not have shown higher participation in screening. Finally, a recent publication also using an insurance claims database showed comparable results: over a period of 10 (not 5) years, 69% of women and 39% of men carried out at least one FIT (4).

The second question is whether this study provides a complete picture of colorectal cancer screening over the whole lifetime in Germany. Most likely it does not. Biennial rather than annual colorectal cancer screening could be sufficient in this age group: only 33.9% of women and 6.5% of men completed two screening tests in the period analyzed. While the participation rate among 50- to 54-year-olds is low, European Health Survey data show that almost 70% of 50- to 74-year-olds in Germany take advantage of screening. This is comparable with or better than neighboring countries (5). The poor coverage in the 50- to 54-year age range is plainly partially compensated among older persons.

Third: Is there room for improvement in this age group? The answer is obvious: yes. The passive approach in Germany—mailing a single letter every 5 years with information about a test that is then only available upon request to a doctor—does not capitalize on extensive evidence about effective interventions to increase the participation rate. In contrast, more frequent advance notifications, invitations, and reminders work. A personalized screening recommendation might also trigger more active screening behavior, This approach is being assessed in the Swiss PRESENT-CRC trial (6). Moreover, consistent support from a physician has great potential. The stark differences between men and women suggest that this role is more often fulfilled by gynecologists than by other specialists. Further research should explore in more detail what form of engagement and what resources are needed to reinforce support from other care providers, particularly primary care physicians (7). Not least, access to tests could be facilitated: they could be provided by other healthcare professionals such as pharmacists, or ordered online directly by the target population. Primary care is overloaded in most countries, and the need for an appointment during working hours represents a serious constraint to many 50- to 54-year-olds. Direct mailing of an order slip rather than a FIT kit helps to avoid waste, particularly in countries with persisting frequent use of colonoscopy for screening (8).

Conclusion

Colorectal cancer screening has proven its value. Ways must now be sought to ensure the broadest possible coverage of the population with tests. Given that the age-related increase in colorectal cancer incidence climbs steeply from the age of 50 years, this article represents a call to reinforce efforts to screen 50- to 54-year-olds in Germany, particularly among men. Although other sources suggest that most of the population up to the age of 65 years is at least partially screened, there remains enormous unexploited potential to prevent colorectal cancer. One can only hope that the article on the following pages will stimulate action in this regard.

Conflict of interest statement
KS and VH are lead investigators for the PRESENT-CRC trial, funded by the Swiss National Science Foundation (6).

Corresponding author
PD Dr. med. Kevin Selby

Cite this as:
Selby K, Hess V: Realizing the full potential of population-based screening for colorectal cancer. Dtsch Arztebl Int 2025; 122: 453–4. DOI: 10.3238/arztebl.m2025.0127

References

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2. Castells A, Quintero E, Bujanda L, et al.: Effect of invitation to colonoscopy versus faecal immunochemical test screening on colorectal cancer mortality (COLONPREV): A pragmatic, randomised, controlled, non-inferiority trial. Lancet 2025; 405: 1231–9

3. Klimeck L, Heisser T, Hennig B, Graf C, Hoffmeister M, Brenner H: Fecal occult blood tests for colorectal cancer screening in routine medical care: A longitudinal analysis from Germany. Dtsch Arztebl Int 2025; 122: 455–60. DOI: 10.3238/arztebl.m2025.010

4. Hornschuch M, Schwarz S, Haug U: High utilization of colonoscopy and fecal occult blood testing for screening or diagnostic purposes in Germany: A longitudinal analysis. Eur J Cancer Prev; 9900

5. Ola I, Cardoso R, Hoffmeister M, Brenner H: Utilization of colorectal cancer screening tests across European countries: A cross-sectional analysis of the European health interview survey 2018-2020. Lancet Reg Health Eur 2024; 41: 100920

6. Selby K, Durand MA, Hess V: PREcision ScrEeniNg for ColoRectal Cancer: A randomized non-inferiority Trial (PRESENT CRC). Swiss National Science Foundation. https://data.snf.ch/grants/grant/221652 (last accessed on 25 June 2025).

7. Senore C, Inadomi J, Segnan N, Bellisario C, Hassan C: Optimising colorectal cancer screening acceptance: A review. Gut 2015; 64: 1158–77

8. Gruner LF, Hoffmeister M, Ludwig L, Meny S, Brenner H: The effects of differing invitation models on the uptake of immunological fecal occult blood testing. Dtsch Arztebl Int 2020; 117: 423–30