Meta-analysis of the influence of time interval between radical operation and preoperative chemoradiotherapy on complete pathological response in rectal cancer patients
Purpose: To evaluate the impact of interval between chemoradiotherapy (CRT) and surgery on rates of pathological complete response (pCR).
Methods: A search was carried out from PubMed and Embase databases for literature related to clinical benefits in rectal cancer patients after surgery performed at different intervals following neoadjuvant therapy. The main endpoint was the rate of pCR. Relative risk (RR) of chance of a pCR among different intervals was assessed.
Results: Among 3462 screened individuals, 11 retrospective cohort studies representing 3462 relevant patients were qualified for inclusion in the study. The time intervals varied between ≤ 5 weeks and > 12 weeks. Thell studies were divided into 6 categories based on surgical timing. The potential association between the pCR rate and time intervals of 5, 6, 7, 8, 10 or 12 weeks was analyzed. Pooled RR and 95 % confidence intervals (CIs) of pCR rates at different intervals were plotted on a line chart. The highest plateau in the RR of pCR rates were noted in patients undergoing surgery beyond 7 weeks (RR, 1.60; 95 % CI, 1.20 – 2.13; p = 0.001) after the end of CRT.
Conclusion: Radical operation over 7 weeks following CRT results in the highest risk of pCR. The question as to whether this is associated with high long-term survival rate remains to be resolved.
Keywords: Rectal cancer, Time interval, Surgery, Chemotherapy, Radiotherapy