Background: Screening for colon cancer (CC) may not only reduce its occurrence but has also the potential to reduce the overall mortality. So far, there has been little evidence that detection of colon cancer by screening colonoscopy results in different survival rates compared to symptomatic patients.
Patients and methods: Clinical, histological, diagnostic, and survival data of 1016 consecutive patients with CC from a prospectively expanded single-institutional database were analyzed for diagnostic, treatment, and prognostic factors. Findings were then stratified according to detection by screening colonoscopy vs. patients who became symptomatic prior to further diagnostic work-up.
Results: 7.1 % of all patients were identified by screening colonoscopy for colon cancer. Screened patients were younger (68.2 vs. 64.8 years), had smaller T stage (p = 0.032), lower tumor stage (p = 0.009), and a tendency to less lymph node metastasis. Overall survival was superior in screened patients, and stage-specific survival showed a tendency to improved survival, which was not statistically significant. Furthermore, a higher percentage of screened patients underwent adjuvant chemotherapy (84.6 vs. 55.0 %, p = 0.032).
Conclusion: Survival outcome and enrollment in a multimodal treatment was higher in screening-detected patients compared to patients diagnosed after the onset of clinical symptoms. Besides a potential occurrence of lead time bias, these findings strongly support the need for continued improvement of screening programs and the recruitment of more patients for colorectal cancer screening.
Keywords: Adenoma-carcinoma sequence; Colon cancer; Colonoscopy; Lead time bias; Surgery; Survival.