Short-term Outcomes of Elective Surgery Following Self-Expandable Metallic Stent and Neoadjuvant Chemotherapy in Patients With Left-Sided Colon Cancer Obstruction

Effects of neoadjuvant chemotherapy for patients with obstructive colon cancer: A multicenter propensity score-matched analysis (YCOG2101)

Aim

Obstructive colon cancer is locally advanced colon cancer with poor prognosis. However, the effect of neoadjuvant chemotherapy (NAC) on obstructive colon cancer remains unclear. Therefore, this study aimed to investigate the safety and efficacy of NAC in patients with obstructive colon cancer.

Methods

From January 2012 to December 2017, we collected patient data for clinical stage II/III obstructive colon cancer at seven Yokohama Clinical Oncology Group (YCOG) institutions. The long-term outcomes of the NAC and non-NAC groups were analyzed retrospectively after adjusting for patients' background characteristics using propensity score matching.

Results

Among the 202 eligible patients, propensity score matching extracted 51 patients each for the NAC and non-NAC groups. After matching, the groups showed no marked differences in the background factors. All the patients in the NAC group underwent diverting stoma construction. Nineteen patients (37.3%) experienced grade 3-4 adverse events during NAC. The incidence of postoperative complications was similar between groups. The 5-year progression-free survival rates were 75.8% in the NAC group and 63.0% in the non-NAC group (p = 0.22, log-rank test). The 5-year overall survival rates were 88.5% in the NAC group and 78.8% in the non-NAC group (p = 0.09, log-rank test).

Conclusion

Although NAC was feasible for obstructive colon cancer after diverting stoma construction, its effects on long-term outcomes could not be proven.

Colonic stent as a bridge to surgery versus emergency rection for malignant left-sided colorectal obstruction: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

The role of self-expanding metal stent (SEMS) implantation as a bridge to surgery in malignant left-sided colorectal obstruction (MLCO) remains controversial.

OBJECTIVE

To evaluate the safety of SEMS implantation versus emergency surgery (ER) in the treatment of MLCO.

METHODS

Four major literature databases (Cochrane Library, Embase, PubMed, and Web of Science) were searched to collect articles published before April 20, 2023. After determining random or fixed-effect models based on heterogeneity tests, odds ratios (RR) or standardized mean differences (SMD) with their respective 95% confidence intervals (CI) were calculated.

RESULTS

Nineteen randomized controlled studies were included. The main outcomes included overall tumor recurrence rate, 30-day mortality rate, and overall incidence of complications. Secondary outcomes included mortality-related indicators, tumor recurrence-related indicators, surgery-related indicators, and other relevant indicators. The study found that there was no significant difference in the 30-day mortality rate between the SEMS group and the er group. However, the SEMS group had a lower overall incidence of complications (RR = 0.787, P = .004), lower incision infection rate (RR = 0.472, P = .003), shorter operation time (SMD = -0.591, P = .000), lower intraoperative blood loss (SMD = -1.046, P = .000), lower intraoperative transfusion rate (RR = 0.624, P = .021), lower permanent stoma rate (RR = 0.499, P = .000), lower overall stoma rate (RR = 0.520,P = .000), shorter hospital stay (SMD = -0.643, P = .014), and more lymph node dissections during surgery (SMD = 0.222, 95% CI: 0.021-0.423, P = .031), as well as a higher primary anastomosis rate (RR = 0.472, 95% CI: 0.286-0.7 77, P = .003), among other advantages. However, the SEMS group had a higher overall tumor recurrence rate (RR = 1.339, P = .048).

CONCLUSION

SEMS has significant advantages over er in relieving clinical symptoms and facilitating postoperative recovery in MLCO, but does not reduce the tumor recurrence rate. Neoadjuvant chemotherapy combined with SEMS may provide a new approach to the treatment of MLCO.

Oncologic safety of colonic stenting as a bridge to surgery in left-sided malignant colonic obstruction: Current evidence and prospects

Approximately 7%-29% of patients with colorectal cancer present with colonic obstruction. The concept of self-expandable metal stent (SEMS) insertion as a bridge to surgery (BTS) is appealing. However, concerns on colonic stenting possibly impairing oncologic outcomes have been raised. This study aimed to review current evidence on the short- and long-term oncologic outcomes of SEMS insertion as BTS for left-sided malignant colonic obstruction. For short-term outcomes, colonic stenting facilitates a laparoscopic approach, increases the likelihood of primary anastomosis without a stoma, and may decrease postoperative morbidity. However, SEMS-related perforation also increases local recurrence and impairs overall survival. Moreover, colonic stenting may cause negative oncologic outcomes even without perforation. SEMS can induce shear forces on the tumor, leading to increased circulating cancer cells and aggressive pathological characteristics, including perineural and lymphovascular invasion. The conflicting evidence has led to discordant guidelines. Well-designed collaborative studies that integrate both oncologic outcomes and data on basic research (e.g., alteration of circulating tumors) are needed to clarify the actual benefit of colonic stenting as BTS.