Obstructive Colorectal Cancer Research Articles

Long-Term Outcomes of Self-Expandable Metallic Stents as a Bridge to Surgery for Obstructive and Symptomatic Primary Tumors of Stage IV Colorectal Cancer: A Propensity-Score Analysis.

Background: Self-expandable metallic stent (SEMS) was introduced for the treatment of obstructive colorectal cancer (CRC) a few decades ago. However, its long-term outcomes remain controversial, especially for stage IV CRC. The aim of this study was to clarify the outcomes of SEMS as a "bridge to surgery" (BTS) for obstructive and symptomatic primary tumors in stage IV CRC by one-to-one propensity-score matching. Materials and Methods: This retrospective cohort study was conducted at a single center from January 2007 to December 2017. Patients with obstructive and symptomatic primary tumors of stage IV CRC underwent primary resection (PR) or placement of a SEMS as a BTS. They were divided into SEMS and PR groups, and their short- and long-term outcomes were compared. Results: In total, 52 patients were reviewed (SEMS group, 21; PR group, 31). Sixteen patients in both groups were matched using propensity scores. Patients in the SEMS group more frequently underwent laparoscopic surgery than those in the PR group (75% versus 19%, P = .004). The two groups showed no significant differences in perioperative and pathological outcomes. The 5-year overall survival was not significantly different between groups (29% versus 20%, P = .53). Conclusions: As a BTS, the use of SEMS for obstructive and symptomatic primary tumors in CRC stage IV can be a comparable option to PR in terms of short- and long-term outcomes, and would be less invasive with respect to surgical procedures.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer.

Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking. We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20days. In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72). A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

Colon stenting as a bridge to surgery in obstructive colorectal cancer management.

Colonic stent placement is a commonly used bridging strategy for surgery in patients with obstructive colorectal cancer. The procedure involves the placement of a self-expandable metallic stent (SEMS) across the obstructive lesion to restore intestinal patency and alleviate the symptoms of obstruction. By allowing patients to receive surgery in a planned and staged manner with time for preoperative optimization and bowel preparation, stent placement may reduce the need for emergency surgery, which is associated with higher complication rates and poorer outcomes. This review focuses on the role of colon stenting as a bridge to surgery in the management of obstructive colorectal cancer. SEMS as a bridge to surgery for left-sided colon cancer has been demonstrated to be particularly useful; however, further research is needed for its application in cases of right-sided colon cancer. Colon stent placement also has limitations and potential complications including stent migration, re-obstruction, and perforation. However, the timing of curative surgery after SEMS placement remains inconclusive. Considering the literature to date, performing surgery at an interval of approximately 2 weeks is considered appropriate. Therefore, colonic stent placement may be an effective strategy as a bridge to surgery in patients with obstructive colorectal cancer.

Artificial intelligence algorithms for predicting post-operative ileus after laparoscopic surgery

ObjectiveBy constructing a predictive model using machine learning and deep learning technologies, we aim to understand the risk factors for postoperative intestinal obstruction in laparoscopic colorectal cancer patients, and establish an effective artificial intelligence-based predictive model to guide individualized prevention and treatment, thus improving patient outcomes. MethodsWe constructed a model of the artificial intelligence algorithm in Python. Subjects were randomly assigned to either a training set for variable identification and model construction, or a test set for testing model performance, at a ratio of 7:3. The model was trained with ten algorithms. We used the AUC values of the ROC curves, as well as accuracy, precision, recall rate and F1 scores. ResultsThe results of feature engineering composited with the GBDT algorithm showed that opioid use, anesthesia duration, and body weight were the top three factors in the development of POI. We used ten machine learning and deep learning algorithms to validate the model, and the results were as follows: the three algorithms with best accuracy were XGB (0.807), Decision Tree (0.807) and Neural DecisionTree (0.807); the two algorithms with best precision were XGB (0.500) and Decision Tree (0.500); the two algorithms with best recall rate were adab (0.243) and Decision Tree (0.135); the two algorithms with highest F1 score were adab (0.290) and Decision Tree (0.213); and the three algorithms with best AUC were Gradient Boosting (0.678), XGB (0.638) and LinearSVC (0.633). ConclusionThis study shows that XGB and Decision Tree are the two best algorithms for predicting the risk of developing ileus after laparoscopic colon cancer surgery. It provides new insight and approaches to the field of postoperative intestinal obstruction in colorectal cancer through the application of machine learning techniques, thereby improving our understanding of the disease and offering strong support for clinical decision-making.

Short-term and long-term oncologic outcomes of self-expandable metallic stent compared with tube decompression for obstructive colorectal cancer: a systematic review and meta-analysis.

Patients with obstructive colorectal cancer managed by emergency surgery show high morbidity, mortality, and stoma formation rates. Decompression modalities, including the self-expandable metallic stent (SEMS) and tube drainage (TD), have been used to improve surgical outcomes. However, there have been limited studies comparing the 2 modalities. We performed a meta-analysis on short- and long-term outcomes between SEMS and TD. PubMed, EMBASE, Cochrane Library, and Google Scholar were searched. Data were pooled, and the overall effect size was calculated using random effect models. Outcome measures were perioperative short-term and 3-year survival outcomes. We included 20 nonrandomized studies that examined 2,047 patients in the meta-analysis. The meta-analysis showed SEMS had better short-term outcomes in clinical success rate, decompression-related complications, laparoscopic surgery rate, stoma formation rate, and postoperative complication rate with a relative risk (RR) of 0.36 (95% confidence interval [CI], 0.24-0.54; I2 = 20%), 0.32 (95% CI, 0.20-0.50; I2 = 0%), 0.47 (95% CI, 0.34-0.66; I2 = 87%), 0.34 (95% CI, 0.24-0.49; I2 = 52%), and 0.70 (95% CI, 0.54-0.89, I2 = 28%), respectively. However, there was no significant difference between the 2 groups in 3-year overall survival (RR, 0.99; 95% CI, 0.77-1.27; I2 = 0%). Although the long-term oncologic impact of SEMS is still unclear compared with TD, the results of this meta-analysis may suggest that SEMS insertion can be performed more successfully and safely and may have benefits for short-term perioperative outcomes compared with TD. Further studies are warranted to provide more definitive survival results.

Prognostic significance of Ishii’s sarcopenia screening score for patients undergoing curative surgery for obstructive colorectal cancer after intraluminal decompression

Prognostic significance of Ishii’s sarcopenia screening score for patients undergoing curative surgery for obstructive colorectal cancer after intraluminal decompression

Morusinol Extracted from Morus alba Inhibits Cell Proliferation and Induces Autophagy via FOXO3a Nuclear Accumulation-Mediated Cholesterol Biosynthesis Obstruction in Colorectal Cancer.

The incidence rate of colorectal cancer (CRC) has been increasing significantly in recent years, and it is urgent to develop novel drugs that have more effects for its treatment. It has been reported that many molecules extracted from the root bark of Morus alba L. (also known as Cortex Mori) have antitumor activities. In our study, we identified morusinol as a promising anticancer agent by selecting from 30 molecules extracted from Morus alba L. We found that morusinol treatment suppressed cell proliferation and promoted apoptosis of CRC cells in vitro. Besides this, we observed that morusinol induced cytoprotective autophagy. The GO analysis of differentially expressed genes from RNA-seq data showed that morusinol affected cholesterol metabolism. Then we found that key enzyme genes in the cholesterol biosynthesis pathway as well as the sterol regulatory element binding transcription factor 2 (SREBF2) were significantly downregulated. Furthermore, additional cholesterol treatment reversed the anti-CRC effect of morusinol. Interestingly, we also found that morusinol treatment could promote forkhead box O3 (FOXO3a) nuclear accumulation, which subsequently suppressed SREBF2 transcription. Then SREBF2-controlled cholesterol biosynthesis was blocked, resulting in the suppression of cell proliferation, promotion of apoptosis, and production of autophagy. The experiments in animal models also showed that morusinol significantly impeded tumor growth in mice models. Our results suggested that morusinol may be used as a candidate anticancer drug for the treatment of CRC.

Modified Naples prognostic score for evaluating the prognosis of patients with obstructive colorectal cancer

BackgroundInflammatory, immune, and nutritional status are key factors in obstructive colorectal cancer (OCRC). This study aims to investigate the value of modified Naples prognostic score (M-NPS) in evaluating OCRC prognosis.MethodsA total of 196 OCRC patients were retrospectively analyzed to construct M-NPS based on serum albumin (ALB), total cholesterol (CHOL), neutrophil:lymphocyte ratio (NLR), and lymphocyte:monocyte ratio (LMR), and then they were divided into three groups. The Kaplan–Meier (KM) method and Cox proportional hazard regression analysis were performed for overall survival (OS) and disease-free survival (DFS) of OCRC patients.ResultsPatients with high M-NPS had worse OS and DFS (P = 0.0001, P = 0.0011). Multivariate COX analysis showed that M-NPS was an independent prognostic factor for OCRC patients. Patients in the M-NPS 2 group had significantly worse OS (hazard ratio [HR] = 4.930 (95% confidence interval [95% CI], 2.217–10.964), P < 0.001) and DFS (HR = 3.508 (95% CI, 1.691–7.277), P < 0.001) than those in the 0 group.ConclusionM-NPS was an independent prognostic factor for OCRC patients; it might provide a potential reference for immunonutritional intervention in patients with obstruction.

Self-expanding metal stents versus decompression tubes as a bridge to surgery for patients with obstruction caused by colorectal cancer: a systematic review and meta-analysis

BackgroundUsing self-expanding metal stents (SEMS) and decompression tubes (DT) as a bridge-to-surgery (BTS) treatment may avoid emergency operations for patients with colorectal cancer-caused obstructions. This study aimed to evaluate the efficacy and safety of the two approaches.MethodsWe systematically retrieved literature from January 1, 2000, to May 30, 2023, from the PubMed, Embase, Web of Science, SinoMed, Wanfang Data, Chinese National Knowledge Infrastructure, and Cochrane Central Register of Clinical Trials databases. Randomized controlled trials (RCTs) or cohort studies of SEMS versus DT as BTS in colorectal cancer obstruction were selected. Risks of bias were assessed for RCTs and cohort studies using the Cochrane Risk of Bias tool version 2 and Risk of Bias in Nonrandomized Studies of Interventions. Certainty of evidence was determined using the Graded Recommendation Assessment. Odds ratio (OR), mean difference (MD), and 95% confidence interval (95% CI) were used to analyze measurement data.ResultsWe included eight RCTs and eighteen cohort studies involving 2,061 patients (SEMS, 1,044; DT, 1,017). Pooled RCT and cohort data indicated the SEMS group had a significantly higher clinical success rate than the DT group (OR = 1.99, 95% CI 1.04, 3.81, P = 0.04), but no significant difference regarding technical success (OR = 1.29, 95% CI 0.56, 2.96, P = 0.55). SEMS had a shorter postoperative length of hospital stays (MD = − 4.47, 95% CI − 6.26, − 2.69, P < 0.00001), a lower rates of operation-related abdominal pain (OR = 0.16, 95% CI 0.05, 0.50, P = 0.002), intraoperative bleeding (MD = − 37.67, 95% CI − 62.73, − 12.60, P = 0.003), stoma creation (OR = 0.41, 95% CI 0.23, 0.73, P = 0.002) and long-term tumor recurrence rate than DT (OR = 0.47, 95% CI 0.22, 0.99, P = 0.05).ConclusionSEMS and DT are both safe as BTS to avoid emergency surgery for patients with colorectal cancer obstruction. SEMS is preferable because of higher clinical success rates, lower rates of operation-related abdominal pain, intraoperative bleeding, stoma creation, and long-term tumor recurrence, as well as a shorter postoperative length of hospital stays.Trial registrationCRD42022365951.

Colonic Resection, Stoma, or Self-expanding Metal Stents for Obstructive Left Colon Cancer: the CROSCO-1 study protocol.

Colorectal cancer (CRC) is one of the most common cancers worldwide. There are several causes of a mechanical left bowel obstructive but CRC accounts for approximately 50% of cases and in 10-30% of whom it is the presenting syndrome. In most cases, the left colon is involved. At present, the range of therapeutic alternatives in the management of obstructive left CRC in emergency conditions (primary resection vs. staged resection with applied self-expanding metallic stents) is broad, whereas internationally validated clinical recommendations in each condition are still lacking. This enormous variability affects the scientific evidence on both the immediate and long-term surgical and oncological outcomes. CROSCO-1 (Colonic Resection, Stoma or Self-expanding Metal Stents for Obstructive Left Colon Cancer) study is a national, multi-center, prospective observational study intending to compare the clinical results of all these therapeutic regimens in a cohort of patients treated for obstructive left-sided CRC. The primary aim of the CROSCO-1 study is the 1-year stoma rate of patients undergoing primary emergency surgical resection (Hartmann procedure or primary resection and anastomosis) compared with patients undergoing staged resection. Secondary outcomes are 30-day and 90-day major morbidity and mortality, 1-year quality of life and the timing of chemotherapy initiation in the two groups. Future CROSCO studies will follow in which, instead, we will evaluate the long-term oncological outcomes of the two treatment strategies. The results of a large prospective cohort study which will analyze what really happens in the common clinical practice of managing patients with obstructive left CRC will have the aim of understanding which is the best strategy in terms of surgical and oncological outcomes. Indeed, the CROSCO-1 study will analyze the early surgical outcomes for patients with obstructed left CRC. Future CROSCO studies will follow in which, instead, we will evaluate the long-term oncological outcomes of the two treatment strategies.

Influence of endoscopists' expertise level on clinical outcomes after bridge-to-surgery stenting in obstructive colorectal cancer.

This study aimed to investigate the effect of stenting-related factors, including endoscopists' expertise, on clinical outcomes after bridge-to-surgery (BTS) stenting for obstructive colorectal cancer (CRC). We analyzed BTS stenting-related factors, including stenting expertise and the interval between stenting and surgery, in 233 patients (63 [13] years, 137 male) who underwent BTS stenting for obstructive CRC. We evaluated the influence of these factors on post-BTS stenting clinical outcomes such as stent-related complications and cancer recurrence. The interval between stenting and surgery was ≤7days in 79 patients (33.9%) and >7days in 154 patients (66.1%). BTS stenting was performed by endoscopists with ≤50, 51-100, and >100 prior stenting experiences in 94, 43, and, 96 patients, respectively. The clinical success rate of BTS stenting was 93.1%. Stent-related and postoperative complications developed in 19 (8.2%) and 20 (8.6%) patients, respectively. Cancer recurrence occurred in 76 patients (32.6%). Short BTS interval of ≤7days increased the risk of postoperative complications (odds ratio [OR], 2.61 [1.03-6.75]; P=0.043). Endoscopists' stenting experience >100 showed greater clinical success of stenting (OR, 5.50 [1.45-28.39]; P=0.021) and fewer stent-related complications (OR, 0.26 [0.07-0.80]; P=0.028) compared with stenting experience ≤50. BTS stenting-related factors did not affect long-term oncological outcomes. Greater expertise of endoscopists was associated with better short-term outcomes, including high stenting success rate and low rate of stent-related complications after BTS stenting for obstructive CRC. An interval of >7days between BTS stenting and surgery was required to decrease postoperative complications.

Importance of preoperative total colonoscopy and endoscopic resection after self-expandable metallic stent placement for obstructive colorectal cancer as a bridge-to-surgery

Background and aimColonic self-expandable metallic stent (SEMS) placement enables preoperative total colonoscopy (TCS) in patients with obstructive colorectal cancer. Following SEMS placement, it is possible to assess the presence or absence of synchronous proximal colon cancers and perform preoperative endoscopic resection (ER) for neoplastic lesions proximal to the primary lesion. The objective of this study was to determine the usefulness and safety of preoperative TCS and ER after SEMS placement in patients with obstructive colorectal cancer.MethodsFrom April 2016 to March 2022, we enrolled 100 patients with obstructive colorectal cancer who underwent SEMS placement, including 86 patients who underwent preoperative TCS after SEMS placement. Complications associated with preoperative TCS and ER after SEMS placement and the characteristics of the neoplastic lesions were assessed.ResultsThe success rate of SEMS placement as bridge-to-surgery was 98.0%; six patients had associated complications. Preoperative TCS was performed 8 (range: 1–30) days after SEMS placement. Four patients had synchronous advanced cancers. Nine non-advanced synchronous cancers, 116 adenomas, and 18 sessile-serrated lesions were treated by preoperative TCS and ER after SEMS placement. No procedure-related complications, namely stent migration, bleeding, and perforation were observed. Forty-five patients underwent follow-up TCS 1 year after surgery. Only one patient with submucosal invasive cancer required a second surgery.ConclusionsPreoperative TCS and ER after SEMS placement was performed with no complications. This approach allows preoperative evaluation of the entire colon and the treatment of precancerous lesions. (240 words)

A South African central hospital's experience with malignant colorectal obstruction.

The spectrum and outcome of colorectal cancer (CRC) presenting with obstruction is not well studied in low- to middle-income countries (LMIC) and could have implications for health policy. This study aimed to address this deficit in an LMIC setting. A retrospective analysis was conducted of patients with large bowel obstruction, during the period 2000-2019 from the prospective Inkosi Albert Luthuli Central Hospital (IALCH) CRC registry data. Data analysed included the site of CRC, tumour differentiation, management of patients with obstructive CRC, resection margins post resection, oncological management and reasons for failure to receive oncological therapy. Patient follow-up and recurrence were recorded. Malignant obstruction from CRC occurred in 510 patients (20% of the CRC registry). Median age at presentation was 57 years (IQR 48-67). One hundred and seventy-six (34.5%) and 135 (26.5%) had stage III and IV disease respectively. Moderately differentiated cancer was seen in 335 (65.6%). Management was resection (370; 72.5%), diverting colostomy (123; 24.1%) and stent insertion (55; 10.8%). Twenty-one patients (5.7%) had positive resection margins. Recurrence occurred in 34 patients (6.7%), all of whom had initially undergone resection, giving a recurrence rate of 9.8% in those receiving surgery. Median disease-free interval for patients developing recurrence was 21 months (IQR 12-32). One in five patients with CRC presented with obstruction. These patients were younger than in high incomecountry (HIC) series. Over 70% underwent resection. Stomas were used twice as frequently as stents to relieve the obstruction, a finding that is the reverse of that in HICs.

P-157 Factors associated with success rates and complications of metal stent insertion for left-sided colorectal cancer obstruction

P-157 Factors associated with success rates and complications of metal stent insertion for left-sided colorectal cancer obstruction

Low Geriatric Nutritional Risk Index (GNRI) Predicts Poorer Survival in Patients with Obstructive Colorectal Cancer Who Had a Self-Expandable Metallic Stent (SEMS) Inserted as a Bridge to Curative Surgery.

The geriatric nutritional risk index (GNRI) is a nutrition-related risk index calculated easily from serum albumin and the ratio of body weight to ideal body weight. We investigated the prognostic values of the GNRI in elderly patients with obstructive colorectal cancer (OCRC) who had a self-expandable metallic stent inserted as a bridge to curative surgery. We retrospectively evaluated 61 patients aged ≥65 years with pathological stage I to III OCRC. Associations of preoperative GNRI and pre-stenting GNRI (ps-GNRI) with short- and long-term outcomes were examined. Multivariate analyses revealed GNRI of <85.3 and ps-GNRI of <92.9 were independently associated with worse cancer-specific survival (CSS; P = 0.016, and P = 0.041, respectively), and overall survival (OS; P = 0.020, and P = 0.024, respectively). A ps-GNRI of <92.9 was correlated with poorer relapse-free survival (RFS) only in the univariate analysis (P = 0.034). For the OCRC cohort without age restriction (n = 86), GNRI of <85.3 and ps-GNRI of <92.9 were independently associated with worse CSS (P = 0.021), and OS (P = 0.023), respectively. In univariate analysis, ps-GNRI of <92.9 was significantly correlated with poorer RFS (P = 0.006). Moreover, ps-GNRI of <92.9 was significantly associated with Clavien-Dindo grade of ≥III postoperative complications (P = 0.037), anastomotic leak (P = 0.032), infectious complications (P = 0.002), and longer postoperative hospital stay (17 days vs. 15 days; P = 0.048). In OCRC patients, decreased preoperative and pre-stenting GNRI were significantly correlated with poorer survival, and decreased pre-stenting GNRI was significantly associated with worse short- and long-term outcomes.

Nomogram for predicting the probability of permanent stoma in patients with acute obstructive colorectal cancer.

Acute obstructive colorectal cancer is a high-risk emergency among colorectal cancer (CRC). Approximately 20% of CRC patients are associated with a permanent stoma, which greatly affects the lifestyle of patients. This study aimed to investigate risk factors for predicting permanent stoma (PS) in patients with acute obstructive colorectal cancer. We retrospectively analyzed the clinical-pathological features of patients with acute obstructive colorectal cancer who underwent treatments from our hospital between January 2015 and December 2020. Univariate and multivariate logistic regression analyses were used to evaluate the risk factors for predicting PS chances of CRC patients using a nomogram method. Furthermore, the operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to assess the discrimination power of the nomogram. Calibration plot was used to evaluate nomogram's calibration. A total of 98 patients with acute obstructive colorectal cancer were enrolled in this study, including 24 PS patients with permanent stoma and 74 non-PS patients. Multivariate analysis showed that age [odds ratio (OR): 1.068, 95% confidence interval (CI): 1.006 ~ 1.135, P = 0.032], carcinoembryonic antigen (CEA) [OR: 1.015, 95% CI: 1.003 ~ 1.028, P = 0.013], and surgical method [emergency group vs. stent group, OR: 14.066, 95% CI: 3.625 ~ 54.572, p < 0.001] were independent risk factors for PS. These risk factors were incorporated into a nomogram and showed that the AUC of the nomogram was 0.867 (95% CI: 0.782-0.951). The calibration plot got consistent with prediction for PS in the nomogram. Age, CEA, and surgical method were independent risk factors for PS in patients with acute obstructive colorectal cancer. Our nomogram has favorable predictive power for PS in CRC patients.

Radiomics approach with deep learning for predicting T4 obstructive colorectal cancer using CT image.

Patients with T4 obstructive colorectal cancer (OCC) have a high mortality rate. Therefore, an accurate distinction between T4 and T1-T3 (NT4) in OCC is an important part of preoperative evaluation, especially in the emergency setting. This paper introduces three models of radiomics, deep learning, and deep learning-based radiomics to identify T4 OCC. We established a dataset of computed tomography (CT) images of 164 patients with pathologically confirmed OCC, from which 2537 slides were extracted. First, since T4 tumors penetrate the bowel wall and involve adjacent organs, we explored whether the peritumoral region contributes to the assessment of T4 OCC. Furthermore, we visualized the radiomics and deep learning features using the t-distributed stochastic neighbor embedding technique (t-SNE). Finally, we built a merged model by fusing radiomic features with deep learning features. In this experiment, the performance of each model was evaluated by the area under the receiver operating characteristic curve (AUC). In the test cohort, the AUC values predicted by the radiomics model in the dilated region of interest (dROI) was 0.770. And the AUC value of the deep learning model with the patches extended 20-pixel reached 0.936. Combining the characteristics of radiomics and deep learning, our method achieved an AUC value of 0.947 in the T4 and non-T4 (NT4) classification, and increased the AUC value to 0.950 after the addition of clinical features. The prediction results of our merged model of deep learning radiomics outperformed the deep learning model and significantly outperformed the radiomics model. The experimental results demonstrate that combining the peritumoral region improves the prediction performance of the radiomics model and the deep learning model.

Safety of early surgery after self-expandable metallic stenting for obstructive left-sided colorectal cancer.

Self-expanding metallic stenting (SEMS) is usual for the temporary resolution of obstructive left-sided colorectal cancer (CRC) as a bridge to elective surgery. However, there is no consensus regarding adequate time intervals from stenting to radical surgery. The aim of this study was to identify the optimal time interval that results in favorable short- and long-term outcomes. Data on patients with obstructive left-sided CRC who underwent elective radical surgery after clinically successful SEMS deployment in five tertiary referral hospitals from 2004 to 2016 were analyzed, retrospectively. An inverse probability treatment-weighted propensity score analysis was used to minimize bias. Postoperative short- and long-term outcomes were compared between two groups: an early surgery (within 8days) group and delayed surgery (after 8days) group. Of 311 patients, 148 (47.6%) underwent early and 163 (52.4%) underwent delayed surgery. The median surgery interval was 9.0days. After adjustment, the groups had similar patient and tumor characteristics. In terms of short-term outcomes, there was no difference in hospitalization length or postoperative complications. No deaths were observed. With a median follow-up of 71.0months, no significant difference was observed between the groups in 5-year overall survival (early vs. delayed surgery: 79.6% vs. 71.3%, P = 0.370) and 5-year disease-free survival (early vs. delayed surgery: 59.1% vs. 60.4%, P = 0.970). In obstructive left-sided CRC, the time interval between SEMS and radical surgery did not significantly influence short- and long-term outcomes. Therefore, early surgery after SEMS could be suggested if there is no reason to postpone surgery for preoperative medical optimization.

Treatment of obstructive colorectal cancer

Obstructive colorectal cancer is a common malignant bowel obstruction. Colostomy or colostomy following tumor resection may be the first choice for emergency surgery. The intestinal and systemic conditions of patients undergoing emergency surgery are often poor, and patients need to undergo multiple operations, which increase the surgical risk and economic burden and reduce the quality of life of patients. Poor intraoperative visualization may also affect the radical operation of emergency surgery. Transanal decompression tube (TDT) can rapidly decompress and drain the obstructed bowel, effectively relieve obstruction symptoms, and improve the success rate of primary radical resection. The TDT squeeze the tumor lightly, causing no spread of tumor cells, and is cheap, but the cavity of transanal decompression tube is small and easily blocked, and requires tedious flushing or regular replacement. Self-expanding metallic stents (SEMS) can relieve intestinal obstruction effectively, provide sufficient preparation time for preoperative examination and improvement of nutritional status. By improving patient's tolerance to radical surgery, SEMS might be used as an important treatment strategy choice for obstructive colorectal cancer. However, SEMS may squeeze the tumor, leading to the spread of tumor cells, increase the recurrence rate and metastasis rate, and reduce the survival rate. Moreover, intestinal wall edema still existed during the operation following SEMS, and the rate of ostomy after anastomosis was as high as 34%. We hypothesized that prolonging the interval between stent insertion and surgery to 2 months, with neoadjuvant chemotherapy administered during this interval (SEMS-neoadjuvant chemotherapy strategy), would help improve outcomes. The SEMS-neoadjuvant chemotherapy strategy is a safe, effective, and well tolerated treatment approach with a high laparoscopic resection rate, low stoma formation rate and improvement in the overall survival for patients with left-sided colon cancer obstruction. The patient physical status is improved, the primary tumor is downstaged, and intestinal wall edema is relieved during the relatively longer interval between SEMS placement and surgery. The SEMS-neoadjuvant chemotherapy strategy may be a preferred therapeutic strategy for obstructive left colon cancer.

Self-expandable metallic stents as a bridge to surgery in obstructive right- and left-sided colorectal cancer: a multicenter cohort study

The insertion of a self-expandable metal stent (SEMS) has been proposed as an alternative to emergent surgery (ES) for obstructive colorectal cancer (CRC). We aimed to evaluate the perioperative and oncologic outcomes of SEMS as a bridge to surgery in obstructive CRC, as compared with ES. We retrospectively reviewed the medical records of patients who underwent curative resection of obstructive CRC at four Hallym University-affiliated hospitals between January 2010 and December 2019. All patients were analyzed overall colon, then according to the side of obstruction (overall, right or left). Of 167 patients, 52 patients underwent ES and 115 underwent SEMS insertion and surgery (SEMS group). The postoperative hospital stay and time to soft diet were shorter in the SEMS group than in the ES group for overall and both sided cancer. The SEMS group had lower rates of stoma formation and severe complications for overall and for left-sided cancer. The 5-year overall survival (P = 0.682) and disease-free survival (P = 0.233) rates were similar in both groups. SEMS insertion as a bridge to surgery was associated with faster recovery, a lower rate of stoma formation with similar oncologic outcomes to those of ES.