Safety and feasibility of neoadjuvant chemotherapy as a surgical bridge for acute left-sided malignant colorectal obstruction: a retrospective study

Oncologic oUTcomes of neoadjuvant chemotherapy for obSTructive colon cAncer after steNt decompression (OUTSTAND trial); A study protocol of multicenter non-inferiority randomized controlled trial

BACKGROUND

For obstructive colon cancer, many studies have been conducted on the use of self-expandable metallic stents (SEMS) as a bridge to surgery (BTS). However, there are currently no available prospective data on the impact of bridging period and there is a lack of research on the effects of neoadjuvant chemotherapy during the bridging period.

OBJECTIVES

Patients who undergo successful SEMS placement for obstructive left-sided colon adenocarcinoma without metastases will be eligible for this study.

DESIGN

This study is a multicenter, non-inferiority, randomized (1:1), open-label, controlled trial.

METHODS & ANALYSIS

The patients assigned to the control group will undergo curative surgery within two weeks after successful SEMS placement. The patients assigned to the experimental group will undergo three cycles of neoadjuvant FOLFOX chemotherapy within two weeks after successful SEMS placement. Curative surgery will be performed within four weeks of the last administration of neoadjuvant FOLFOX. Circulating tumor DNA (ctDNA) will be collected at specific time points.

DISCUSSION

The optimal time interval for SEMS placement as a BTS can significantly impact long-term oncologic outcomes. In this study, our goal is to identify the optimal time interval for SEMS placement as a BTS. Recently, there has been interest in applying neoadjuvant chemotherapy for locally advanced colon cancer. In the context of early treatment for tumor dissemination following SEMS placement, neoadjuvant chemotherapy may be beneficial for delayed surgery after SEMS placement as a BTS. The results of this trial will be an important reference for the application of neoadjuvant chemotherapy in locally advanced colon cancer. Additionally, researchers will investigate whether ctDNA can serve as a reliable indicator to guide decisions about the timing and type of subsequent treatment. Based on the results of this trial, a patient-tailored treatment strategy can be developed for obstructive colon cancer.

REGISTRATION

This study is registered on ClinicalTrials.gov Identifier: NCT04889820, registered on May 17, 2021 in clinicaltrials.gov; Protocol ID: XC21MIDI0004.

The optimal surgical time after stent placement in obstructive colorectal cancer: impact on long-term survival of patients

OBJECTIVE

To investigate the optimal interval between self-expanding metal stent (SEMS) placement and radical surgery in patients with obstructive colorectal cancer.

METHOD

In this study, a retrospective research design was used to select 125 patients with obstructive colorectal cancer who underwent colonoscopic SEMS placement with subsequent radical surgery between February 2011 and November 2022 at Shanghai Changhai Hospital. In addition, their clinical data and therapeutic efficacy were examined. Grouping: grouping on the basis of the interval of bridge to surgery (BTS). Group A: interval of BTS ≤ 14 days; group B: 14 days < interval of BTS ≤ 21 days; group C1: interval of BTS > 21 days; group C2: interval of BTS > 21 days, excluding patients who received neoadjuvant therapy; group D: patients who received neoadjuvant therapy. Patients were grouped according to their different surgical methods, group E: patients who received open surgery and group F: patients undergoing laparoscopic surgery.

RESULTS

A total of 125 patients were included in this study, the mean age of the patients was 61.34 ± 13.99 years, with the median follow-up time was 39 (25-61) months. Of these, 84 cases (67.2%) underwent open surgery, while 41 cases (32.8%) underwent laparoscopic surgery. Among the cohort, 15 patients received neoadjuvant radiotherapy and chemotherapy after placement of SEMS. There was a significant difference in preoperative hemoglobin levels between group A and both group B and group C1. The laparoscopic surgery rate was significantly higher in group B than in the other two groups (48.57% versus 3.33% and 22.81%, P = 0.038). The 5-year disease-free survival (DFS) of group C1 patients was lower than that in group A and group B (32.4% versus 56.3%, 62.3%, P = 0.038; P = 0.043), whereas there was no statistical difference in the 5-year overall survival (OS) (60.7% versus 62.1%, 69.6%, P = 0.365, P = 0.339). group D showed a higher proportion of open surgery and a higher T-stage (P < 0.05), resulting in a 5-year DFS that was inferior to group A and group B (17.7% versus 56.3%, 62.3%, P = 0.045; P = 0.047). However, there was no significant difference compared with group C2 (17.7% versus 36.9%, P > 0.05). The 5-year OS of group D was not statistically significantly different from that of group A, group B, and group C2 (28.4% versus 62.1%, 69.6%, 73.4%, P = 0.089, P = 0.090, P = 0.183). In addition, no statistically significant differences were identified in 5-year DFS (49.9% versus 37.0%, P = 0.555) or 5-year OS (66.2% versus 62.6%, P = 0.062) between group E and group F CONCLUSIONS: Radical surgery performed 14-21 days apart after SEMS placement has been shown to improve minimally invasive rates and 5-year DFS rates. The addition of neoadjuvant radiotherapy and chemotherapy during the interval does not appear to improve long-term survival, although this conclusion is based on the results of only 15 patients.

Impact of self-expanding metal stents on long-term survival outcomes as a bridge to surgery in patients with colon cancer obstruction: Current state and future prospects

Since self-expanding metal stents (SEMS) were first introduced in acute colon cancer obstruction, the increased rate of primary anastomosis and improved quality of life following SEMS placement have been clearly shown. However, it was demonstrated that SEMS are associated with higher recurrence rates. Although several trials have shown that overall and disease-free survival in patients following SEMS placement is similar with patients undergoing emergency surgery, obstruction and a high incidence of recurrence imposed many concerns. The optimal time interval from SEMS to surgery is still a matter of debate. Some studies have recommended a time interval of ~2 weeks between SEMS insertion and elective surgery. A prolonged interval of time from SEMS insertion to elective surgery and the administration of neoadjuvant chemotherapy (NAC) has been proposed. SEMS-NAC might have advantages for improving the surgical and long-term survival outcomes of patients with acute colon cancer obstruction, which is an optional approach in the management of acute 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.

Current landscape of preoperative neoadjuvant therapies for initial resectable colorectal cancer liver metastasis

Colorectal cancer liver metastasis (CRLM) presents a clinical challenge, and optimizing treatment strategies is crucial for improving patient outcomes. Surgical resection, a key element in achieving prolonged survival, is often linked to a heightened risk of recurrence. Acknowledging the potential benefits of preoperative neoadjuvant chemotherapy in managing resectable liver metastases, this approach has gained attention for its role in tumor downsizing, assessing biological behavior, and reducing the risk of postoperative recurrence. However, the use of neoadjuvant chemotherapy in initially resectable CRLM sparks ongoing debates. The balance between tumor reduction and the risk of hepatic injury, coupled with concerns about delaying surgery, necessitates a nuanced approach. This article explores recent research insights and draws upon the practical experiences at our center to address critical issues regarding considerations for initially resectable cases. Examining the criteria for patient selection and the judicious choice of neoadjuvant regimens are pivotal areas of discussion. Striking the right balance between maximizing treatment efficacy and minimizing adverse effects is imperative. The dynamic landscape of precision medicine is also reflected in the evolving role of gene testing, such as RAS/BRAF and PIK3CA, in tailoring neoadjuvant regimens. Furthermore, the review emphasizes the need for a multidisciplinary approach to navigate the complexities of CRLM. Integrating technical expertise and biological insights is crucial in refining neoadjuvant strategies. The management of progression following neoadjuvant chemotherapy requires a tailored approach, acknowledging the diverse biological behaviors that may emerge. In conclusion, this review aims to provide a comprehensive perspective on the considerations, challenges, and advancements in the use of neoadjuvant chemotherapy for initially resectable CRLM. By combining evidence-based insights with practical experiences, we aspire to contribute to the ongoing discourse on refining treatment paradigms for improved outcomes in patients with CRLM.

PARP Inhibitors in Colorectal Malignancies: A 2023 Update

BACKGROUND

Colorectal carcinoma (CRC) is one of the most common malignancies in the Western world, and metastatic disease is associated with a dismal prognosis. Poly-ADpribose polymerase (PARP) inhibitors gain increasing attention in the field of medical oncology, as they lead to synthetic lethality in malignancies with preexisting alterations in the DNA damage repair (DDR) pathway. As those alterations are frequently seen in CRC, a targeted approach through PARP inhibitors is expected to benefit these patients, both alone and in combination with other agents like chemotherapy, immunotherapy, antiangiogenics, and radiation.

OBJECTIVE

This review article aims to better clarify the role of PARP inhibitors as a treatment option in patients with metastatic CRC with alterations in the DDR pathway.

METHODS

We used the PubMed database to retrieve journal articles and the inclusion criteria were all human studies that illustrated the effective role of PARP inhibitors in patients with metastatic CRC with homologous repair deficiency (HRD) and the correct line of therapy.

RESULTS

Current evidence supports the utilization of PARP inhibitors in CRC subgroups, as monotherapy and in combination with other agents. Up to now, data are insufficient to support a formal indication, and further research is needed.

CONCLUSION

Efforts to precisely define the homologous repair deficiency (HRD) in CRC - and eventually the subgroup of patients that are expected to benefit the most - are also underway.