Effects of Preoperative Chemoradiotherapy on the Likelihood of Sphincter Preservation Surgery in Locally Advanced Distal Rectal Cancer: A Longitudinal Study Based on Pelvic Magnetic Resonance Imaging

Effect of pathological complete response after neoadjuvant chemoradiotherapy on postoperative complications of rectal cancer: a systematic review and meta-analysis

BACKGROUND

Standard total mesorectal resection has become an important treatment option for locally advanced or high-risk rectal cancer after neoadjuvant chemo-radiotherapy. 15-27% of patients can achieve pathological complete response (PCR) after neoadjuvant chemo-radiotherapy (nCRT). However, the relationship between PCR and postoperative complications remains an important unsolved problem. The objective of this study was to determine whether PCR was associated with the rate of postoperative complications.

METHODS

This meta-analysis was implemented following the recommendations from Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched electronic literature by PubMed, EMBASE, and Google Scholar. Major outcomes of interest included anastomotic leakage, surgical-site infection, reoperation, and any postoperative complications. Other outcomes comprised postoperative hemorrhage, ileus, and mortality.

RESULTS

Eleven thousand two hundred ninety patients in 9 studies were included in the meta-analysis. The pooled analysis revealed that patients with PCR did not have a higher risk of anastomotic leakage (OR = 1.22, 95% CI 0.92-1.62, p = 0.17), reoperation (OR = 1.13, 95% CI 0.93-1.37, p = 0.22), and any postoperative complications (OR = 1.02, 95% CI 0.91-1.15, p = 0.72) than patients with non-PCR. However, the meta-analysis showed that the PCR group was superior to the non-PCR group in terms of surgical-site infection (9.38% vs. 12.44%OR = 0.68, 95% CI 0.47-0.98; p = 0.04).

CONCLUSION

PCR might not be related to the occurrence of postoperative complications in rectal cancer patients following nCRT. In addition, PCR might be associated with a lower risk of surgical-site infection.

Neoadjuvant chemoradiation improves oncologic outcomes in low and mid clinical T3N0 rectal cancers

BACKGROUND

Controversial data exists in the current literature in regard to the use of neoadjuvant chemoradiation (nCRT) in patients with clinical T3N0 (cT3N0) rectal cancers, specifically based on location and relation to peritoneal reflection. We aimed to analyze the impact of nCRT on oncologic outcomes among cT3N0 rectal cancers, depending on the tumor height from anal verge (AV).

METHODS

A retrospective analysis of patients with cT3N0 rectal cancers was included from a query of a prospectively maintained rectal cancer database from 1980 to 2016. Patients were divided into 3 groups based on the tumor height: low (1-5 cm from AV), mid (6-10 cm from AV), and upper (11-15 cm from AV). Patients were stratified by use of nCRT.

MAIN OUTCOMES

5-year overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and local recurrence (LR) using Kaplan-Meier curves.

RESULTS

Five hundred ninety-two patients were included. Overall, 364 (61.4%) patients received nCRT and 228 (38.6%) patients did not. There were 251 (43%) patients with low, 302 (51%) with mid, and 39 (7%) with upper rectal cancer. Patients with low and mid rectal cancers received nCRT more frequently than those with upper rectal cancers (68.5% and 61.2% vs 43.6%, p = 0.007). The 5-year OS was 78% and 63%, DFS-88% and 73%, LR-1% and 8% in nCRT followed by resection vs. surgery alone (p < 0.001). In regard to cancer location after nCRT compared with surgery alone, low and mid cancers had better OS, DFS, and CSS, compared with upper ones.

CONCLUSION

nCRT prolongs survival among patients with rectal cancer below 10 cm from AV; however, it has no effect on 5-year oncologic survival of patients with upper rectal cancer located below peritoneal reflection.

Is Preoperative Chemoradiotherapy Beneficial for Sphincter Preservation in Low-Lying Rectal Cancer Patients?

The present study explored the benefit of preoperative chemoradiotherapy (PCRT) for sphincter preservation in locally advanced low-lying rectal cancer patients who underwent stapled anastomosis, especially in those with deep and narrow pelvises determined by magnetic resonance imaging.Patients with locally advanced low-lying rectal cancer (≤5 cm from the anal verge) who underwent stapled anastomosis were included. Patients were categorized into two groups (PCRT+ vs. PCRT-) according to PCRT application. Patients in the PCRT+ group were matched to those in the PCRT- group according to potential confounding factors (age, gender, clinical stage, and body mass index) for sphincter preservation. Sphincter preservation, permanent stoma, and anastomosis-related complications were compared between the groups. Pelvic magnetic resonance imaging was used to measure 12 dimensions representing pelvic cavity depth and width with which deep and narrow pelvis was defined. The impact of PCRT on sphincter preservation and permanent stoma in pelvic dimensions defined as deep and narrow pelvis was evaluated, and factors associated with sphincter preservation and permanent stoma were analyzed.One hundred sixty-six patients were one-to-one matched between the PCRT+ and PCRT- groups. Overall, sphincter-saving surgery was performed in 66.3% and the rates were not different between the 2 groups. Anastomotic complications and permanent stoma occurred nonsignificantly more frequently in the PCRT+ group. PCRT was not associated with higher rate of sphincter preservation in all pelvic dimensions defined as deep and narrow pelvis, while PCRT was related to higher rate of permanent stoma in shorter transverse diameter and interspinous distance. On logistic regression analysis, PCRT was not shown to influence both sphincter preservation and permanent stoma, while longer transverse diameter and interspinous distance were associated with lower rate of permanent stoma.PCRT had no beneficial effect on sphincter preservation in patients with locally advanced low-lying rectal cancer who had undergone stapled anastomosis. In patients with deep and narrow pelvis, PCRT had no impact on sphincter preservation but was associated with higher rate of permanent stoma.

Effect of Interval between Neoadjuvant Chemoradiotherapy and Surgery on Oncological Outcome for Rectal Cancer: A Systematic Review and Meta-Analysis

Aim. To evaluate the influence of interval between neoadjuvant chemoradiotherapy (NCRT) and surgery on oncological outcome. Methods. A systematic search was conducted in PubMed, the Cochrane Library, and Embase databases for publications reporting oncological outcomes of patients following rectal cancer surgery performed at different NCRT-surgery intervals. Relative risk (RR) of pathological complete response (pCR) among different intervals was pooled. Results. Fifteen retrospective cohort studies representing 4431 patients met the inclusion criteria. There was a significantly increased rate of pCR in patients treated with surgery followed 7 or 8 weeks later (RR, 1.45; 95% CI, 1.18-1.78; and P < 0.01 and RR, 1.49; 95% CI, 1.15-1.92; and P = 0.002, resp.). There is no consistent evidence of improved local control or overall survival with longer or shorter intervals. Conclusion. Performing surgery 7-8 weeks after the end of NCRT results in the highest chance of achieving pCR. For candidates of abdominoperineal resection before NCRT, these data support implementation of prolonging the interval after NCRT to optimize the chances of pCR and perhaps add to the possibility of ultimate organ preservation.