Oncologic effects of adjuvant chemotherapy in patients with ypT0-2N0 rectal cancer after neoadjuvant chemoradiotherapy and curative surgery: a meta-analysis.

PURPOSE

The role of adjuvant chemotherapy for patients with ypT0-2N0 rectal cancer following neoadjuvant chemoradiotherapy (nCRT) and curative surgery is uncertain. We performed a meta-analysis using selected studies to compare adjuvant chemotherapy with observation for this cohort of patients.

METHODS

PubMed, Embase, and the Cochrane Library were searched. Data were pooled, and overall effect size was calculated using random effect models. Outcome measures were 5-year overall survival (OS), disease-free survival (DFS), local, and distant recurrence.

RESULTS

We included 17 nonrandomized studies for qualitative analysis and 16 nonrandomized studies that examined 4,747 patients for the meta-analysis. In analysis of patients with ypT0N0 rectal cancer, adjuvant chemotherapy had no significant effect on OS (odds ratio [OR], 1.53; 95% confidence interval [CI], 0.86-2.72; I = 27%), DFS (OR, 1.22; 95% CI, 0.61-2.42; I = 5%), local recurrence (OR, 0.78; 95% CI, 0.08-7.37; I = 0%), and distant recurrence (OR, 1.04; 95% CI, 0.41-2.62; I = 0%). In analysis of patients with ypT1-2N0 rectal cancer, adjuvant chemotherapy also had no significant effect on OS (OR, 2.15; 95% CI, 0.59-7.80; I = 26%), DFS (OR, 1.66; 95% CI, 0.35-7.85; I = 44%), local recurrence (OR, 2.56; 95% CI, 0.72-9.13; I = 0%), and distant recurrence (OR, 1.15; 95% CI, 0.23-5.87; I = 0%).

CONCLUSION

Adjuvant chemotherapy may have no oncologic benefits in patients with ypT0-2N0 rectal cancer after nCRT and radical surgery. Routine use of adjuvant chemotherapy for those patients may be avoided.