Optimal postoperative surveillance strategies for stage III colorectal cancer

Colonoscopy, imaging, and carcinoembryonic antigen: Comparison of guideline adherence to surveillance strategies in patients who underwent resection of colorectal cancer - A systematic review and meta-analysis

INTRODUCTION

Almost one-third of patients with colorectal cancer (CRC) experience recurrence after resection. Adherence to surveillance guidelines largely dictates efficacy in early detection of recurrence. We sought to assess and compare adherence to postoperative surveillance guidelines for colonoscopy, imaging, and Carcinoembryonic Antigen (CEA).

METHODS

PubMed, Medline, Embase, Scopus, Cochrane, Web of Science, and CINAHL were systematically searched. Random-effects meta-analysis was performed and pooled adherence to each surveillance strategy was assessed for CEA, imaging, and colonoscopy.

RESULTS

Overall 14 studies (55,895 patients) met the inclusion criteria. Adherence to colonoscopy guidelines was the highest (70%, 95%CI 67-73), followed by imaging (63%, 95%CI 47-80), and CEA (54%; 95%CI 42-66). Among 7 (50%) studies that examined adherence to the American Society of Clinical Oncology guidelines, compliance with colonoscopy was the highest (73%; 95% CI 70-76), followed by imaging (58%; 95% CI 37-78), and CEA (45%; 95%CI 37-52). Of note, guideline adherence to CEA testing was much lower than colonoscopy among patients with colon (OR 0.21; 95%CI 0.20-0.22) and rectal cancer (OR 0.25; 95%CI 0.23-0.28) (both p < 0.05). This was also noted when compared with imaging recommendations among older patients (OR = 0.62; 95%CI 0.42-0.93) and patients with stage II, (OR = 0.80; 95%CI 0.76-0.84) and stage III disease (OR = 0.88; 95%CI 0.82-0.94) (all p < 0.05).

CONCLUSION

While guideline adherence to postoperative surveillance with colonoscopy was high, adherence to CEA testing and imaging surveillance strategies was markedly lower following CRC resection. Future studies should investigate avenues to improve compliance with surveillance guidelines among health care providers and patients to optimize postoperative follow-up for CRC.

Circulating Tumor DNA, Imaging, and Carcinoembryonic Antigen: Comparison of Surveillance Strategies Among Patients Who Underwent Resection of Colorectal Cancer-A Systematic Review and Meta-analysis

BACKGROUND

Almost one-third of colorectal cancer (CRC) patients experience recurrence after resection; nevertheless, follow-up strategies remain controversial. We sought to systematically assess and compare the accuracy of carcinoembryonic antigen (CEA), imaging [positron emission tomography (PET) and computed tomography (CT) scans], and circulating tumor DNA (CtDNA) as surveillance strategies.

PATIENTS AND METHODS

PubMed, Medline, Embase, Scopus, Cochrane, Web of Science, and CINAHL were systematically searched. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to assess methodological quality. We performed a bivariate random-effects meta-analysis and reported pooled sensitivity, specificity, and diagnostic odds ratio (DOR) values for each surveillance strategy.

RESULTS

Thirty studies were included in the analysis. PET scans had the highest sensitivity to detect recurrence (0.95; 95%CI 0.91-0.97), followed by CT scans (0.77; 95%CI 0.67-0.85). CtDNA positivity had the highest specificity to detect recurrence (0.95; 95%CI 0.91-0.97), followed by increased CEA levels (0.88; 95%CI 0.82-0.92). Furthermore, PET scans had the highest DOR to detect recurrence (DOR 120.7; 95%CI 48.9-297.9) followed by CtDNA (DOR 37.6; 95%CI 20.8-68.0).

CONCLUSION

PET scans had the highest sensitivity and DOR to detect recurrence, while CtDNA had the highest specificity and second highest DOR. Combinations of traditional cross-sectional/functional imaging and newer platforms such as CtDNA may result in optimized surveillance of patients following resection of CRC.