Colorectal Cancer Fast Tracks: Cancer Yield and the Predictive Value of Entry Criteria

SIMPLE SUMMARY: Fast-track pathways to detect colorectal cancer have been implemented in several European countries, using different entry criteria. We analyzed 2539 fast-track colonoscopies including referrals in detail, in order to calculate the predictive values and odds ratios of different red flags with respect to the risk for colorectal cancer. Interestingly, we observed that a number of red flags were not at all associated with an increased risk for colorectal cancer. On the other hand, the variable with the highest predictive value: a positive fecal occult blood test (FOBT), is not always part of colorectal cancer fast tracks. These findings are important when selecting patients for fast-track colonoscopy. We propose that the entry criteria should be limited to the following signs/symptoms: patients > 40 years with one or more of the following signs/symptoms: positive FOBT, abnormal radiology, abnormal rectal examination, visible blood in stool, in the absence of hemorrhoids and unexplained iron-deficiency anemia. ABSTRACT: Background: Fast-track pathways for diagnosing colorectal cancer (CRC) have been implemented in several European countries. In Sweden, a substantial number of CRC are diagnosed via the Swedish Standardized Course of Care for colorectal cancer (SCC-CRC). We evaluated the SCC-CRC in terms of CRC yield, and predictive values and odds ratios (OR) for the entry criteria. Methods: We retrospectively analyzed all 2539 patients referred for SCC-CRC colonoscopy between September 2016 and December 2020. Entry criteria and colonoscopy outcomes were analyzed. Results: CRC yield was 16.4%. Highest positive predictive values (PPVs) were seen for abnormal radiology (PPV 30.5%, OR 4.7 (95% CI 3.4–6.4) p < 0.001), abnormal rectal examination (PPV 28%, OR 3.6 (95% CI 2.7–4.8) p < 0.001), and anemia (PPV 24.8%, OR 2.2 (95% CI 1.5–3.1) p < 0.001). Some entry criteria showed no significant risk increase, i.e., visible blood in stool/rectal bleeding, change in bowel habits, and the combination of changed bowel habits plus anemia. A positive fecal immunochemical test (FIT), although not part of the SCC-CRC, showed the highest OR: 9.9 (95% CI 4.5–21.7) p < 0.001) and PPV of 18.8%. Conclusions: CRC yield from the SCC-CRC is slightly higher compared to other European fast tracks. A number of entry criteria showed no benefit towards assessing CRC risk. FIT testing should be included in CRC fast tracks to increase diagnostic efficacy.