Perineural invasion is increased in patients receiving colonic stenting as a bridge to surgery: a systematic review and meta-analysis

Combining single-cell spatial transcriptomics and molecular simulation to develop in vivo probes targeting the perineural invasion region of adenoid cystic carcinoma

Background and objectives

Perineural invasion (PNI) refers to the invasion, encasement, or penetration of tumor cells around or through nerves. Various malignant tumors, including pancreatic cancer, head and neck tumors, and bile duct cancer, exhibit the characteristic of PNI. Particularly, in head and neck-skull base tumors such as adenoid cystic carcinoma (ACC), PNI is a significant factor leading to incomplete surgical resection and postoperative recurrence.

Methods

Spatial transcriptomic and single-cell transcriptomic sequencing were conducted on a case of ACC tissue with PNI to identify potential probes targeting PNI. The efficacy of the probes was validated through in vivo and in vitro experiments.

Results

Spatial transcriptomic and single-cell RNA sequencing revealed phenotypic changes in Schwann cells within the PNI region of ACC. Peptide probes were designed based on the antigen-presenting characteristics of Schwann cells in the PNI region, which are dependent on Major Histocompatibility Complex II (MHC-II) molecules. Successful validation in vitro and in vivo experiments confirmed that these probes can label viable Schwann cells in the PNI region, serving as a tool for dynamic in vivo marking of tumor invasion into nerves.

Conclusions

Peptide probes targeting Schwann cells' MHC-II molecules have the potential to demonstrate the occurrence of PNI in patients with ACC.

Does Colorectal Stenting as a Bridge to Surgery for Obstructive Colorectal Cancer Increase Perineural Invasion?

Objectives

To clarify whether self-expandable metallic stent (SEMS) placement for obstructive colorectal cancer (CRC) increases perineural invasion (PNI), thereby worsening the prognosis.

Methods

In total, 1022 patients with pathological T3 or T4 colon or rectosigmoid cancer who underwent resection were retrospectively reviewed. The study patients were divided into a no obstruction group (n=693), obstruction without stent group (n=251), and obstruction with stent group (n=78), and factors demonstrating an independent association with PNI, the difference in PNI incidence and severity between groups, and the association between PNI and the duration from SEMS placement to surgery were investigated. Survival analysis was performed for each group.

Results

On multivariate analysis, SEMS placement (hazard ratio [HR]: 2.08) was independently associated with PNI whereas SEMS placement was not. PNI occurred in 39%, 45%, and 68% of the no obstruction, obstruction without stent, and obstruction with stent group, respectively. In the obstruction with stent group, the proportion of PNI was not associated with the duration from SEMS placement to surgery. Extramural PNI, an advanced form of PNI, demonstrated no increase with increasing interval. The five-year OS was 86.3%, 76.7%, and 73.1% in no obstruction, obstruction without stent, and obstruction with stent group, respectively. On multivariate analysis, obstruction was an independent risk factor of decreased OS (HR: 1.57) whereas SEMS placement was not.

Conclusions

The prognosis was comparable between patients with SEMS placement and those with an obstruction who did not undergo SEMS placement, thus demonstrating that SEMS is a viable, therapeutic option for BTS.

Management of obstructed colorectal carcinoma in an emergency setting: An update

Colorectal carcinoma is common, particularly on the left side. In 20% of patients, obstruction and ileus may be the first clinical manifestations of a carcinoma that has advanced (stage II, III or even IV). Diagnosis is based on clinical presentation, plain abdominal radiogram, computed tomography (CT), CT colonography and positron emission tomography/CT. The best management strategy in terms of short-term operative or interventional and long-term oncological outcomes remains unknown. For the most common left-sided obstruction, the first choice should be either emergency surgery or endoscopic decompression by self-expendable metal stents or tubes. The operative plan should be either one-stage or two-stage resection. One-stage resection with on-table bowel decompression and irrigation can be accompanied or not accompanied by proximal defunctioning stoma (colostomy or ileostomy). Primary anastomosis is more convenient but has increased risks of anastomotic leakage and morbidity. Two-stage resection (Hartmann's procedure) is safer and the most widely used despite temporally affecting quality of life. Damage control surgery in high-risk frail patients is less frequently performed since it can be successfully substituted with endoscopic stenting or tubing. For the less common right-sided obstruction, one-stage surgical resection is more beneficial than endoscopic decompression. The role of minimally invasive surgery (laparoscopic or robotic) is a subject of debate. Emergency laparoscopic-assisted management is advantageous to some extent but requires much expertise due to inherent difficulties in dissecting the distended colon and the risk of rupture and subsequent septic complications. The decompressing stent as a bridge to elective surgery more substantially decreases the risks of morbidity and mortality than emergency surgery for decompression and has equivalent medium-term overall survival and disease-free survival rates. Its combination with neoadjuvant chemotherapy or radiation may have a positive effect on long-term oncological outcomes. Management plans are crucial and must be individualized to better fit each case.

The optimal surgery timing after stenting in colorectal cancer patients with malignant obstruction: additionally compared with emergency surgery

BACKGROUND

This study aimed to determine short-term and long-term outcomes according to time intervals after stenting and compared them with those of emergency surgery (ES) in colorectal cancer (CRC) with malignant obstruction.

METHODS

CRC with malignant obstructions was reviewed retrospectively between January 2008 and July 2018. Of a total of 539 patients who visited the emergency room and underwent ES, 133 were enrolled in the ES group. Of a total of 567 patients who initially received stenting and subsequently underwent elective surgery, 220 were enrolled in the SEMS group. The interval between SEMS placement and elective surgery was classified as < 11 days, 11-17 days, and > 17 days.

RESULTS

For those who received SEMS (n = 220), those with a time interval of 11-17 days (n = 97) had fewer hospital days than those with a time interval of < 11 days (n = 68) (8 days vs. 15 days) and less stoma formation than those with a time interval of > 17 days (n = 55) (1.0% vs. 14.6%). Multivariable analysis revealed a decreased risk of death for the group with a time interval of 11-17 days (20.6%) compared to the ES group (31.6%) (hazard ratio: 0.48; 95% confidence interval: 0.24-0.97). Disease-free survival was comparable between the SEMS and ES groups regardless of the time interval (log-rank p = 0.52).

CONCLUSIONS

The time interval of 11-17 days after stenting to elective surgery appeared to be associated with the most favorable outcomes.

Stent as bridge to surgery decreases postoperative complications without worsening oncological outcomes: retrospective unicentric cohort study and stent placement protocol

BACKGROUND

Even if the use of stent as bridge to surgery (BTS) for obstructive colon cancer was described long ago, there is still much controversy on their use. Patient recovery before surgery and colonic desobstruction are just some of the reasons to defend this management that can be found in several available articles.

METHODS

This is a single-center, retrospective cohort study, including patients with obstructive colon cancer treated between 2010 and 2020. The primary aim of this study is to compare medium-term oncological outcomes (overall survival, disease-free survival) between stent as BTS and ES groups. The secondary aims are to compare perioperative results (in terms of approach, morbidity and mortality, and rate of anastomosis/stomas) between both groups and, within the BTS group, analyze whether there are any factors that may influence oncological outcomes.

RESULTS

A total of 251 patients were included. Patients belonging to the BTS cohort presented a higher rate of laparoscopic approach, required less intensive care management, less reintervention, and less permanent stoma rate, when comparing with patients who underwent urgent surgery (US). There were not significant differences in terms of disease-free survival and overall survival between the two groups. Lymphovascular invasion negatively affected oncological results but was not related with stent placement.

CONCLUSION

The stent as a bridge to surgery is a good alternative to urgent surgery, which leads to a decrease in postoperative morbidity and mortality without significantly worsening oncological outcomes.

Delaying surgery for optimization after colonic stent bridging is safe for left-sided malignant large bowel obstruction: Result from 10-year experience and risks factor analysis

AIM

To evaluate the operative and oncological results after colonic stent bridging for left-sided malignant large bowel intestinal obstruction and the risk factors for survival and recurrence after definitive surgery.

METHODOLOGY

Consecutive patients who underwent colonic stenting for malignant left-sided colonic obstruction were included. Patients for palliative stenting or emergency surgery, patient with low rectal tumour or peritoneal metastasis were excluded. The primary outcome was overall survival. Secondary outcomes included stent success rate, stenting related complications, rate of stoma formation and long-term oncological outcome including recurrence rate and recurrence free survival rate.

RESULTS

From June 2011 to June 2021, a total of 222 patients underwent colonic stenting. 112 patients were bridged to surgery after initial stenting, but 7 patients dropped out. Overall survival was 35 months (IQR = 17.75-75.25 months) in the early operation group, 30 months (IQR = 17.5-49.5 months) in the delayed surgery group HR 0.981 (95%CI 0.70-1.395, p = 0.907). Sensitivity analysis performed by excluding stent complications and emergency surgery yielded the same conclusion. Overall stenting complications rate was 17.1%. 11 patients (10.4%) required emergency surgery.

CONCLUSION

There was no difference between early and delayed surgery groups (>4weeks) in the overall survival and recurrence in patients who had stent-bridge to surgery for malignant left colonic obstruction. It is safe to defer definitive surgery to optimize patients and allow better recovery from initial obstruction after colonic stenting before definitive surgery without adversely affecting the oncological outcomes.

A retrospective evaluation of short-term results from colonic stenting as a bridge to elective surgery versus emergency surgery for malignant colonic obstruction

The efficacy and safety of self-expanding metallic stent (SEMS) placement as a bridge to elective surgery versus emergency surgery to treat malignant colonic obstruction is debated. This study aimed to evaluate the outcomes of patients with malignant colonic obstruction treated using different procedure. Subjects admitted to the authors' department with colonic obstruction (n = 87) were studied. They underwent colonic stenting as a bridge to elective surgery (SEMS group: n = 14) or emergency surgery (ES group: n = 22).Their demographic characteristics, stoma rate, laparoscopy rate and postoperative complications were analyzed, and the potential risk factors of postoperative complications and the optimal time interval from SEMS implantation to elective surgery were explored. The stoma rate was 15.4% in the SEMS group versus 60.0% in the ES group (P = 0.015), and the postoperative complication rate was 7.7% in the SEMS group versus 40.0% in the ES group (P = 0.042). The proportion of patients undergoing laparoscopy in SEMS group was significantly higher than that in ES group (69.2% vs. 15.0%; P = 0.003).The effect of ASA grade on postoperative complications was statistically significant (OR = 24.565; P = 0.008). The Receiving operating characteristic (ROC) curve could not determine the optimal time interval between SEMS implantation and elective surgery (AUC = 0.466). SEMS implantation has the advantages of lower temporary stoma rate, less postoperative complications and higher laparoscopy rate compared with ES in the treatment of left malignant intestinal obstruction. ASA grade is a risk factor for postoperative complications. However, larger sample size prospective randomized controlled trials (RCT) are still needed to confirm long-term oncological outcomes.

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.

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.

Colonic stent for bridge to surgery for acute left-sided malignant colonic obstruction: A review of the literature after 2020

It has been found that 8%-29% of colorectal cancers are obstructive. The use of “stent as bridge to surgery” is one of the most debated topics in obstructive left-sided colorectal cancer management. The endoscopic placement of a self-expanding metallic stent as bridge to surgery (BTS) could turn an emergency surgery to an elective one, increasing the number of primary anastomoses instead of stoma and facilitating the laparoscopic approach instead of an open one. However, in recent years the possible risk of perforations and microperforations facilitating cancer spread related to the use of self-expanding metallic stent for BTS has been highlighted. Therefore, despite the useful short-term outcomes related to BTS, the recent literature has focused on long-term outcomes investigating the disease-free survival, the recurrence rate and the overall survival. Due to discordant data, international guidelines are still conflicting, and the debate is still open. There is not agreement about using self-expanding metallic stent for BTS as the gold standard.

Case report: Stent-first strategy as a potential approach in the management of malignant right-sided colonic obstruction with cardiovascular risks

In obstructing left-sided colonic or rectal cancer, endoscopic stent placement with the purpose of decompression and bridge to elective colon resection has been widely utilized and accepted. However, in malignant right-sided colonic obstruction, stent placement prior to colectomy is still highly controversial, due to lower clinical success and high anastomotic leak. We report a case of malignant right-sided colonic obstruction based on the radiological findings of irregular thickening of ascending colon wall and dilation of proximal large bowel on enhanced computed tomography scan. The 72-year-old woman presented with obvious abdominal distension. Due to concerning cardiovascular complications as intermittent chest pain and a long history of type 2 diabetes, a three-step therapeutic plan was instigated. Initially, a self-expandable metallic stent was placed palliatively to relieve the bowel obstruction. Consecutively, coronary angiography was performed, and two coronary stents were implanted to alleviate more than 80% stenosis of two main coronary arteries. One month later, laparoscopic radical resection of right colon and lymphadenectomy were successfully performed, with a blood loss less than 50 millimeters and a harvest of 29 lymph nodes, 1 being positive. The patient was discharged one week postoperatively with no complications, and received adjuvant chemotherapy one month later. During a follow-up of more than one year, the patient was in complete remission with no recurrence and cardiovascular events. In patients presenting with malignant right-sided colonic obstruction and peril of high cardiovascular risks, we propose colonic and coronary stent-first strategy to emergency surgery as a potential approach so as to ensure sufficient cardiovascular preparation improving perioperative safety. Moreover, the anatomical location of the tumor would be significantly achievable thus granting high-quality radical colon resection and lymphadenectomy.

Determinants of emergency presentation in patients with colorectal cancer: a systematic review and meta-analysis

Colorectal cancer remains a significant cause of morbidity and mortality, even despite curative treatment. A significant proportion of patients present emergently and have poorer outcomes compared to elective presentations, independent of TNM stage. In this systematic review and meta-analysis, differences between elective/emergency presentations of colorectal cancer were examined to determine which factors were associated with emergency presentation. A literature search was carried out from 1990 to 2018 comparing elective and emergency presentations of colon and/or rectal cancer. All reported clinicopathological variables were extracted from identified studies. Variables were analysed through either systematic review or, if appropriate, meta-analysis. This study identified multiple differences between elective and emergency presentations of colorectal cancer. On meta-analysis, emergency presentations were associated with more advanced tumour stage, both overall (OR 2.05) and T/N/M/ subclassification (OR 2.56/1.59/1.75), more: lymphovascular invasion (OR 1.76), vascular invasion (OR 1.92), perineural invasion (OR 1.89), and ASA (OR 1.83). Emergencies were more likely to be of ethnic minority (OR 1.58). There are multiple tumour/host factors that differ between elective and emergency presentations of colorectal cancer. Further work is required to determine which of these factors are independently associated with emergency presentation and subsequently which factors have the most significant effect on outcomes.

Effect of self-expandable metal stent on morbidity and mortality and oncological prognosis in malignant colonic obstruction: retrospective analysis of its use as curative and palliative treatment

INTRODUCTION

Acute gastrointestinal obstruction due to colorectal cancer occurs in 7-30% of cases and is an abdominal emergency that requires urgent decompression. The safety and oncological effect of self-expandable metal stents (SEMS) in these patients remains controversial. This study aimed to evaluate its impact on these variables and compare it with that of emergency surgery (ES).

METHODS

Descriptive, retrospective and single-centre study, performed between 2008 and 2015, with follow-up until 2017. One hundred eleven patients with diagnosis of left malignant colonic obstruction were included and divided according to the treatment received: stent as bridge to surgery (SBTS group: 39), palliative stent (PS group: 30) and emergency surgery with curative (ECS group: 34) or palliative intent (EPS group: 8). Treatment was decided by the attending surgeon in charge.

RESULTS

Technical and clinical general success rates for colorectal SEMS were 95.7% and 91.3%, respectively, with an associated morbimortality of 23.2%, which was higher in the PS group (p = 0.002). The SBTS group presented a higher laparoscopic approach and primary anastomosis (p < 0.001), as well as a lower colostomy rate than the ECS group (12.8% vs. 40%; p = 0.023). Postoperative morbidity and mortality were significantly lower in the SBTS group compared to the ECS group (41% vs. 67.6%; p = 0.025). Overall survival (OS) and disease-free survival (DFS) were similar between the analysed groups.

CONCLUSION

Colonic stent placement is a safe and effective therapeutic alternative to emergency surgery in the management of left-sided malignant colonic obstruction in both curative and palliative fields. It presents a lower postoperative morbimortality and a similar oncological prognosis.

What are the factors predictive of postoperative complications in patients with colorectal cancer undergoing stenting as a bridge to surgery?

OBJECTIVE

Using a self-expanding metal stent as a bridge to surgery (BTS) is considered a reasonable strategy for patients with acute malignant large bowel obstruction. Since postoperative complications have a negative impact on patient survival, we aim to clarify the predictors of complications in patients undergoing BTS using a self-expanding metal stent.

METHODS

We conducted a retrospective review of 61 patients with colorectal cancer (CRC) who underwent stenting as a BTS at our institution. We analyzed the association of postoperative complications with clinicopathologic, surgical, and patient factors, and with the prestenting or preoperative laboratory data.

RESULTS

Both postoperative complications in general and severe complications were significantly associated with a longer stenotic-section length (p = 0.007 and p = 0.003), lower preoperative hemoglobin levels (p < 0.001 and p = 0.081), and lower prestenting hemoglobin levels (p = 0.006 and p = 0.042). Multivariate logistic regression analysis showed that lower prestenting (<13.0 g/dl) and preoperative (<11.5 g/dl) hemoglobin levels were independent predictive factors for postoperative complications (odds ratio [OR]: 4.15; 95% confidence interval [CI]: 1.07-18.90; p = 0.040; and OR: 4.93; 95% CI: 1.35-20.28; p = 0.016). A stenotic-section length of 5.0 cm or greater was predictive of severe complications (OR: 25.67; 95% CI: 1.95-1185.00; p = 0.011).

CONCLUSIONS

Our data suggest that lower hemoglobin levels before stenting and a longer length of the stenotic section of bowel might predict postoperative complications in patients with CRC undergoing BTS for obstruction.

Management of obstructive colon cancer: Current status, obstacles, and future directions

Approximately 10%–18% of patients with colon cancer present with obstruction at the initial diagnosis. Despite active screening efforts, the incidence of obstructive colon cancer remains stable. Traditionally, emergency surgery has been indicated to treat patients with obstructive colon cancer. However, compared to patients undergoing elective surgery, the morbidity and mortality rates of patients requiring emergency surgery for obstructive colon cancer are high. With the advancement of colonoscopic techniques and equipment, a self-expandable metal stent (SEMS) was introduced to relieve obstructive symptoms, allowing the patient’s general condition to be restored and for them undergo elective surgery. As the use of SEMS placement is growing, controversies about its application in potentially curable diseases have been raised. In this review, the short- and long-term outcomes of different treatment strategies, particularly emergency surgery vs SEMS placement followed by elective surgery in resectable, locally advanced obstructive colon cancer, are described based on the location of the obstructive cancer lesion. Controversies regarding each treatment strategy are discussed. To overcome current obstacles, a potential diagnostic method using circulating tumor DNA and further research directions incorporating neoadjuvant chemotherapy are introduced.

Treatment outcome of laparoscopic surgery after self-expandable metallic stent insertion for obstructive colorectal cancer

BACKGROUND

We assessed the technical and oncological safety of self-expandable metallic stent (SEMS) insertion followed by laparoscopic colorectal surgery as a bridge to surgery (BTS) for obstructive colorectal cancer (CRC).

METHODS

A retrospective, single-center study analyzed the short- and long-term outcomes of SEMS insertion followed by laparoscopic colorectal surgery in patients with stage II/III/IV obstructive CRC from 2012 to 2020 at Cancer Institute Hospital.

RESULTS

In 66 patients, including 28 stage IV patients, the clinical success rates of SEMS insertion were 97%. In laparoscopic surgery, primary anastomosis was performed in 61 patients (92%), and open conversion was required in 2 patients (3%). Postoperative complications were seen in 9 patients (13%); however, there was no anastomotic leakage or mortality. Curative resection was achieved in all 38 stage II/III patients and 15 of 28 (54%) stage IV patients. Stage IV patients had a longer operation time and greater blood loss than stage II/III patients; however, the open conversion and postoperative complication rates were similar between the groups. In stage II/III patients, 3-year disease-free survival and 3-year overall survival [OS] were 87.1 and 89.5%, respectively. The median OS of stage IV patients was 34.9 months, and stage IV patients who underwent R0 resection showed a significantly better OS (P = 0.0011) than those with R2 resection.

CONCLUSION

SEMS insertion followed by laparoscopic surgery is a feasible treatment strategy that achieves a high-primary anastomosis rate without severe postoperative complication in not only stage II/III but also stage IV obstructive CRC patients.