Diagnostic yield of follow-up in patients undergoing surgery for non-metastatic colorectal cancer.

BACKGROUND

Evidence on adherence, diagnostic performance and impact on survival to intensive follow-up after surgery for colorectal cancer (CRC) is limited.

AIM

To analyze the diagnostic performance of surveillance colonoscopy, computed tomography (CT), and tumor markers (TMs) in detecting CRC recurrence or metastasis during follow-up after CRC resection. Secondary objectives included degree of adherence to clinical practice guidelines surveillance recommendations and factors associated with adherence and all-cause and CRC mortality.

METHODS

The single-center retrospective cohort study including patients undergoing curative resection of stage I-III CRC during 2010-2015. Follow-up was performed using TMs every 6 months, yearly CT for 5 years, and colonoscopy at years 1 and 4. Demographic, primary tumor data, and results at follow-up were collected.

RESULTS

Of 574 included patients included, 153 had recurrences or metastases. Of this group, 136 (88.9%) were diagnosed by CT, 10 (6.5%) by CT and colonoscopy, and 7 (4.6%) by colonoscopy; only 67.8% showed TMs elevation. Adherence to follow-up recommendations was 68.8% for the first colonoscopy, 74% for the first CT scan, and 96.6% for the first blood test; these values declined over time. Younger age at diagnosis [odds ratio (OR) 0.93; 95%CI: 0.91-0.95], CRC stages I-II (OR 0.38; 95%CI: 0.24-0.61), and adherence to follow-up recommendations (OR 0.30; 95%CI: 0.20-0.46) were independently associated with lower risk for all-cause death at 5 years.

CONCLUSION

CT scan had the highest diagnostic yield. Adherence to follow-up recommendations was low and decreased during follow-up. Younger age at diagnosis, stage, and follow-up adherence were associated with lower 5-year mortality.