A prospective, single-arm, multicenter trial of diverting stoma followed by neoadjuvant chemotherapy using mFOLFOX6 for obstructive colon cancer: YCOG 1305 (PROBE study)

The ELECLA trial: A multicentre randomised control trial on outcomes of neoadjuvant treatment on locally advanced colon cancer

BACKGROUND

Colon cancer (CC) is a public health concern with increasing incidence in younger populations. Treatment for locally advanced CC (LACC) involves oncological surgery and adjuvant chemotherapy (AC) to reduce recurrence and improve overall survival (OS). Neoadjuvant chemotherapy (NAC) is a novel approach for the treatment of LACC, and research is underway to explore its potential benefit in terms of survival. This trial will assess the efficacy of NAC in LACC.

METHODS

This is a multicentre randomised, parallel-group, open label controlled clinical trial. Participants will be selected based on homogenous inclusion criteria and randomly assigned to two treatment groups: NAC, surgery, and AC or surgery followed by AC. The primary aim of this study is to evaluate the 2-year progression-free survival (PFS), with secondary outcomes including 5-year PFS, 2- and 5-year OS, toxicity, radiological and pathological response, morbidity, and mortality.

DISCUSSION

The results of this study will determine whether NAC induces a clinical and histological tumour response in patients with CCLA and if this treatment sequence improves survival without increasing morbidity and mortality.

REGISTRATION NUMBER

NCT04188158.

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.

Location matters: spatial dynamics of tumor-infiltrating T cell subsets is prognostic in colon cancer

Background

Colon cancer is a heterogeneous disease and consists of various molecular subtypes. Despite advances in high-throughput expression profiling, limitations remain in predicting clinical outcome and assigning specific treatment to individual cases. Tumor-immune interactions play a critical role, with tumors that activate the immune system having better outcome for the patient. The localization of T cells within tumor epithelium, to enable direct contact, is essential for antitumor function, but bulk DNA/RNA sequencing data lacks spatial distribution information. In this study, we provide spatial T cell tumor distribution and connect these data with previously determined genomic data in the AC-ICAM colon cancer patient cohort.

Methods

Colon cancer patients (n=90) with transcriptome data available were selected. We used a custom multiplex immunofluorescence assay on colon tumor tissue sections for quantifying T cell subsets spatial distribution in the tumor microenvironment, in terms of cell number, location, mutual distance, and distance to tumor cells. Statistical analyses included the previously determined Immunologic Constant of Rejection (ICR) transcriptome correlation and patient survival, revealing potential prognostic value in T cell spatial distribution.

Results

T cell phenotypes were characterized and CD3+CD8-FoxP3- T cells were found to be the predominant tumor-infiltrating subtype while CD3+FoxP3+ T cells and CD3+CD8+ T cells showed similar densities. Spatial distribution analysis elucidated that proliferative T cells, characterized by Ki67 expression, and Granzyme B-expressing T cells were predominantly located within the tumor epithelium. We demonstrated an increase in immune cell density and a decrease in the distance of CD3+CD8+ T cells to the nearest tumor cell, in the immune active, ICR High, immune subtypes. Higher densities of stromal CD3+FoxP3+ T cells showed enhanced survival outcomes, and patients exhibited superior clinical benefits when greater spatial distances were observed between CD3+CD8-FoxP3- or CD3+CD8+ T cells and CD3+FoxP3+ T cells.

Conclusion

Our study's in-depth analysis of the spatial distribution and densities of major T cell subtypes within the tumor microenvironment has provided valuable information that paves the way for further research into the intricate relationships between immune cells and colon cancer development.

Emergency surgery for obstructive splenic flexure colon cancer: results of a multicentric study of the French Surgical Association (AFC)

Management of malignant left-sided colonic obstruction remains challenging and requires a stoma in 40-65% of patients. In those with obstructive splenic flexure colon cancer (OSFCC), a debate still exists regarding the most appropriate surgery. The aim of this muticenter study was to report and compare the different surgical procedures in OSFCC patients with a special focus on operative and histological characteristics and survival outcomes including 12-month stoma-free survival. Between 2000 and 2015, 2325 patients were treated for obstructive colon cancer in centers members of the French National Surgical Association (AFC). Among them, 198 underwent surgery for OSFCC and were retrospectively analyzed. Patients with OSFCC and proximal colonic ischemia or perforation were excluded. Four procedures were performed: decompressing stoma (DS, 39%), splenic flexure colectomy (SFC, 39%), subtotal colectomy (STC, 17%,) and left hemicolectomy (LHC, 5%). All patients treated with LHC underwent a Hartmann's procedure. There was no significant difference between groups for postoperative mortality and morbidity. Hospital stay was significantly longer after DS. The length of the specimen, longitudinal resection margins and number of harvested lymph nodes were significantly higher in the STC group. There was no difference for overall and disease-free survival. Stoma-free survival was significantly lower after LHC (62%) in comparison with the other groups (p < 0.0001). At the end of follow-up, 50% of patients who underwent LHC had a permanent stoma. In OSFCC patients without proximal colonic ischemia or peritonitis, LHC should no longer be recommended due to a high risk of permanent stoma.

Emergency resection or diverting stoma followed by elective resection in patients with colonic obstruction due to locally advanced cancer: a national cohort study

AIM

The aim was to assess long-term prognosis after emergency resection versus primary diverting stoma followed by elective tumour resection.

METHOD

A national-register-based cohort study with retrospective analysis of prospectively collected data was performed. All Swedish patients with non-metastatic obstructive locally advanced colon cancer treated with emergency resection or diverting stoma, followed by an elective resection, between 2007 and 2017 were included. The Kaplan-Meier method and Cox proportional hazards model were used to compare all-cause mortality between patients with emergency resection and elective right- and left-sided resection. The multivariable model was adjusted for year of diagnosis, age at diagnosis, sex, Charlson Comorbidity Index, American Society of Anesthesiologists class, tumour location and pN stage.

RESULTS

In all, 751 patients with a tumour in the right colon and 700 patients with a tumour in the left colon were included. Emergency resection was more common in patients with right-sided colon tumours (681/751) than in patients with left-sided colon tumours (483/700). The 5-year overall survival in patients with right-sided tumours was 25% after emergency resection and 46% after diverting stoma followed by elective resection (log-rank test P = 0.001). The corresponding numbers for patients with left-sided colon tumours were 40% and 64% (P < 0.001). Emergency resection was independently associated with increased all-cause mortality in patients with left-sided tumour (hazard ratio 1.63, 95% CI 1.21-2.19) but not in patients with right-sided tumour (hazard ratio 1.21, 95% CI 0.80-1.81).

CONCLUSION

Diverting stoma followed by elective resection is associated with improved survival compared with emergency resection in patients with left-sided colonic obstruction due to locally advanced tumours.

The Role of Neoadjuvant Chemotherapy in Locally Advanced Colon Cancer

Neoadjuvant systemic therapy has many potential advantages over up-front surgery, including tumor downstaging, early treatment of micrometastatic disease, and providing an in vivo test of tumor biology. Due to these advantages, neoadjuvant therapy is becoming the standard of care for an increasing number of tumor types. Currently, colon cancer patients are still routinely treated with up-front surgery, and neoadjuvant systemic therapy is not yet standard. Limitations to widespread use of neoadjuvant therapy have included inaccurate radiological staging, concerns about tumor progression while undergoing preoperative treatment rendering a patient incurable, and a lack of randomized data demonstrating benefit. However, there is great interest in neoadjuvant chemotherapy, and a number of trials are under way. Early follow up of the first phase III trial of neoadjuvant chemotherapy for colon cancer demonstrated tumor downstaging and suggested an improvement in disease-free survival with neoadjuvant chemotherapy, and it is hoped that this will translate into longer-term overall survival benefit. Clinicians should closely watch this developing field, consider the option of neoadjuvant chemotherapy for colon cancer patients, and actively seek out opportunities for their patients to participate in ongoing clinical trials to further inform this field in future.