Oncologic impact of colonic stents for obstructive left-sided colon cancer

Colonic stenting has had a significant positive impact on the management of obstructive left-sided colon cancer(OLCC) in terms of both palliative treatment and bridge-to-surgery(BTS). Notably, many studies have convincingly demonstrated the effectiveness of stenting as a BTS, resulting in improvements in shortterm outcomes and quality of life, safety, and efficacy in subsequent curative surgery, and increased cost-effectiveness, whereas the safety of chemotherapy after stenting and the long-term outcomes of stenting as a BTS are controversial. Several studies have suggested an increased risk of perforation in patients receiving bevacizumab chemotherapy after colonic stenting. In addition, several pathological analyses have suggested a negative oncological impact of colonic stenting. In contrast, many recent studies have demonstrated that colonic stenting for OLCC does not negatively impact the safety of chemotherapy or long-term oncological outcomes. The updated version of the European Society of Gastrointestinal Endoscopy guidelines released in 2020 included colonic stenting as a BTS for OLCC as a recommended treatment. It should be noted that the experience of endoscopists is involved in determining technical and clinical success rates and possibly oncological outcomes. This review discusses the positive and negative impacts of colonic stenting on OLCC treatment, particularly in terms of oncology.

Stenting as a bridge to surgery in obstructing colon cancer:Longterm recurrence pattern and competing risk of mortality

BACKGROUND Stenting as a bridge to curative surgery(SBTS)for obstructing colon cancer(OCC)has been associated with possibly worse oncological outcomes.AIM To evaluate the recurrence patterns,survival outcomes,and colorectal cancer(CRC)-specific death in patients undergoing SBTS for OCC.METHODS Data from 62 patients undergoing SBTS at a single tertiary centre over ten years between 2007 and 2016 were retrospectively examined.Primary outcomes were recurrence patterns,overall survival(OS),cancer-specific survival(CSS),and CRC-specific death.OS and CSS were estimated using the Kaplan-Meier curves.Competing risk analysis with cumulative incidence function(CIF)was used to estimate CRC-specific mortality with other cause-specific death as a competing event.Fine-Gray regressions were performed to determine prognostic factors of CRC-specific death.Univariate and multivariate subdistribution hazard ratios and their corresponding Wald test P values were calculated.RESULTS 28 patients(45.2%)developed metastases after a median period of 16 mo.Among the 18 patients with single-site metastases:Four had lung-only metastases(14.3%),four had liver-only metastases(14.3%),and 10 had peritoneum-only metastases(35.7%),while 10 patients had two or more sites of metastatic disease(35.7%).The peritoneum was the most prevalent(60.7%)site of metastatic involvement(17/28).The median follow-up duration was 46 mo.26(41.9%)of the 62 patients died,of which 16(61.5%)were CRC-specific deaths and 10(38.5%)were deaths owing to other causes. The 1-, 3-, and 5-year OS probabilities were 88%, 74%, and 59%;1-, 3-, and5-year CSS probabilities were 97%, 83%, and 67%. The highest CIF for CRC-specific death at 60 mowas liver-only recurrence (0.69). Liver-only recurrence, peritoneum-only recurrence, and two ormore recurrence sites were predictive of CRC-specific death.CONCLUSIONThe peritoneum was the most common metastatic site among patients undergoing SBTS. Liveronlyrecurrence, peritoneum-only recurrence, and two or more recurrence sites were predictors ofCRC-specific death.