Proportion and characteristics of screen-detected and non-screen-detected colorectal cancers in Germany

Background: Germany has a long-standing colorectal cancer (CRC) screening offer. We aimed to quantify and characterize screen-detected colorectal cancers (sdCRCs) in Germany. Methods: We conducted a cross-sectional study based on a healthcare database covering similar to 20% of the German population; we included CRC patients aged >= 55 years diagnosed in 2010-2018. Patients with a screening colonoscopy or a fecal occult blood test followed by colonoscopy within 180 days before diagnosis were classified as sdCRCs and compared to non-sdCRCs regarding age, stage and comorbidities. Results: In 2018, 25% of male and 22% of female CRC patients were screen-detected. Regarding characteristics of all included CRC cases (N = 82,538), sdCRC patients were younger than non-sdCRCs (average difference men / women: 2.6 / 4.4 years). The proportion of advanced CRC among sdCRCs and non-sdCRCs, respectively, was 33 and 42% in women (men: 36 and 45%). Severe comorbidities were more prevalent in non-sdCRCs compared to sdCRCs (e.g. in male / female patients aged 65-74: 35% vs. 27% / 26% vs. 19%). Prevalences of hypertension and obesity were similar in both groups. Interpretation: Our study suggests that about one fourth of CRCs in Germany are screen-detected. Among patients with non-sdCRC, not only advanced stage but also severe comorbidity was more common than in sdCRCs.