Short- and Long-term Outcomes After Colonic Stent Insertion as a Bridge to Surgery in Elderly Colorectal Cancer Patients

Background/Aim: Colonic stents have been inserted as a bridge to surgery in patients with resectable colorectal cancer, allowing bowel decompression for systemic assessment and better preparation to avoid stoma construction. However, reports of short- and long-term prognoses for elderly patients remain limited. Patients and Methods: This retrospective study reviewed 175 consecutive patients who underwent colonic stent insertion for bowel obstruction followed by curative colectomy. Patients were divided into those >80 years old (Old, n=49) and those <80 years old (Young, n=126). After propensity score matching, 41 patients in each group matched. Results: Before matching, performance status was poorer (p<0.001), postoperative complication rate was higher (p=0.009), adjuvant chemotherapy rate was lower (p<0.001), and hospital stay was longer (p<0.001) in the Old group. After matching, adjuvant chemotherapy rate was lower (9.8% vs. 39.0%; p=0.003) and hospital stay was longer (14 vs. 12 days; p=0.029) in the Old group. Five-year relapse-free survival (42.9% vs. 68.8%; p=0.200), overall survival (66.3% vs. 87.7%; p=0.081), and cancer-specific survival (68.2% vs. 87.7%; p=0.129) rates were comparable between groups. Conclusion: Colorectal resection after colonic stent insertion is useful for elderly patients, with potential to reduce postoperative complication rates and achieve good long-term results with appropriate case selection.


Patients and Methods
A total of 245 consecutive patients who had undergone colonic stent insertion for bowel obstruction followed by colorectal resection between April 2016 and December 2021 were reviewed using the Nagasaki Colorectal Oncology Group database (Nagasaki University Hospital, Nagasaki Medical Center, Sasebo City General Hospital, Isahaya General Hospital, Ureshino Medical Center, Saiseikai Nagasaki Hospital, and Sasebo city general hospital.Finally, 175 patients diagnosed with Stage II/III pathologically were eligible for analysis.All study protocols were reviewed and approved by the Clinical Research Review Boards (approval no.16062715-5).
Patients were divided into two groups according to age, with an old age group (Old, >80 years old; n=49) and a young age group (Young, <80 years old; n=126).Propensity score matching was applied to minimize the possibility of selection biases and balance covariates that could affect short-term outcomes.The following covariates were included in the score matching: sex, body mass index (BMI), American Society of Anesthesiologists (ASA)performance status (PS), tumor location, comorbidities, surgical approach, and pathological T/N status.Nearest neighbor matching was performed in a 1:1 ratio, with the caliper set at 0.2.Finally, 41 patients in each group were matched.
Clinical features were compared between groups before and after propensity score matching.The following data were collected: sex, BMI, ASA-PS, tumor location, comorbidities, history of abdominal surgery, clinical T/N status, histological type, and ColoRectal Obstruction Scoring System (CROSS) score (15).The CROSS score evaluates oral intake and abdominal symptoms before and after surgery and is scored as follows: CROSS 4, no stenotic symptoms with soft solids, low residue, complete diet; CROSS 3, stenotic symptoms with soft solids, low residue, complete diet; CROSS 2: liquid or enteral nutrition ingestion; CROSS 1: no oral intake; or CROSS 0: continuous decompression required.The surgical and pathological data collected included covering stoma construction, operative procedure, multivisceral resection, number of lymph nodes retrieved, operation time, estimated blood loss, tumor size, pathological T/N status, presence or absence of lymphovascular invasion, postoperative complications, postoperative hospital stay, and presence or absence of adjuvant chemotherapy.Postoperative complications were defined as complications occurring within 30 days of the primary surgery.Patients with Clavien-Dindo grade 2 or higher were included as patients with complications.
Statistical analysis was performed using Bell Curve for Excel software (version 2.02; Social Survey Research Information, Tokyo, Japan).Data are presented as median value and range.Differences in categorical variables were compared using Fisher's exact test or the chi-squared test.Differences in continuous variables were analyzed with the Mann-Whitney U-test.Relapse-free survival (RFS), overall survival (OS) and cancer-specific survival (CSS) were calculated using Kaplan-Meier methods, then differences were tested using the log-rank test.All values of p<0.05 were considered significant.

Results
Table I shows a comparison of clinical characteristics between elderly and young patients with stent insertion.Before propensity score matching, ASA-PS was poorer (PS3; Old, 26.5% vs. Young, 4.8%; p<0.001) in the Old group than in the Young group.Right-side colon cancer tended to be more frequent in the Old group (Old, 36.7% vs. Young, 20.6%; p=0.082).After matching, clinical features were similar between groups.

Discussion
This study compared the short-and long-term outcomes of preoperative colorectal stent insertion in elderly patients with those of younger patients using a multicenter database.Elderly patients were more likely to have poor PS and rightsided colon cancer.After background factors were combined by propensity score matching, the results were similar to those of younger patients in terms of postoperative complications and prognosis.
With the aging of the population, opportunities to treat elderly patients with colorectal cancer are increasing (1,16).Originally, elderly patients were said to have characteristics such as high comorbidity rates and poor PS due to age-related declines in physical conditions and organ functions (17,18).In addition, elderly patients are more likely than younger patients to be diagnosed in an advanced state at the time of detection due to the higher rate of non-adherence to medical examinations and delays in seeking medical care due to declines in PS (19).One of the common complications in such cases of advanced colorectal cancer is obstructive colorectal cancer, which occurs in 8-29% of all colorectal cancer patients (20,21).In a previous study of obstructive colorectal cancer in the elderly, comorbidities were identified in 70% of cases and 54% of cases showed poor PS (14).In the present study, 77% of elderly patients had comorbidities and PS was significantly poorer than that in younger patients.
In the past, treatment of obstructive colorectal cancer often involved emergency surgery with bowel resection or stoma placement (14).However, emergency surgeries have been reported to exhibit higher complication and mortality rates than scheduled surgeries (22).The short-term postoperative outcomes of emergency surgery in elderly patients in poor general condition are even worse (23).Colonic stents represent a potentially useful method to avoid emergency surgery and allow for bowel decompression, appropriate preoperative care, and better preparation for scheduled surgery (11).
Regarding colonic stents, both benefits and complications related to stent insertion (e.g., bowel perforation, re-occlusion, and stent deviation) have been reported (24).In particular, bowel perforation is associated with an increased risk of intraperitoneal spread of cancer, in addition to an increased risk of death from peritonitis and sepsis (25-27).Complications associated with stent insertion were seen in 22 patients (7.2%) (28).The main complications were bowel perforation in five patients (1.6%), stent deviation in 4 patients (1.3%), and obstruction in three patients (1%).Imai et al. reported bowel perforation in 2.4%, stent deviation in 9.8%, and obstruction in 7.3% (29) of patients.In the present study, complications after stent insertion occurred in five patients (2.8%).Of these, three (1.7%) were due to stent deviation and t (1.1%) to restenosis, but in all cases, BTS stenting was achieved and the procedure could be performed safely as described in previous reports (28, 29).
Colonic stent insertion has been reported to reduce postoperative complication rates after BTS (30, 31).Guo et al. studied elderly patients with obstructive colorectal cancer using a single-center database (14).They found that 62.2% One advantage of colonic stent insertion is the lower rate of stoma creation (11,35,36).In a previous report, patients who underwent BTS from a colonic stent had a higher primary anastomosis rate (75.0% vs. 43.4%)and a significantly lower rate of stoma creation (7.5% vs. 56.6%)compared to patients who underwent emergency surgery (11).In the present study, a stoma was created in 9 cases (5.1%), and elderly patients obtained the same reduction in stoma creation rate as younger patients.Elderly patients often have poor PS and encounter difficulties with stoma management, and we believe that colonic stents are likely to prove useful in improving postoperative quality of life (37).
Elderly patients reportedly show an increased risk of colorectal cancer (1).In obstructive colorectal cancer, endoscopically evaluating the colon from the oral side is difficult, and if colorectal cancer from the oral side is found after surgery for obstructive colorectal cancer, resection should be considered again.Frequent general anesthesia can exert adverse effects on cardiopulmonary function and activities of daily living in the elderly (38, 39).Previous reports have suggested that bowel decompression with colonic stents provides an opportunity for accurate preoperative staging and preoperative total colonoscopy to search for proximal colorectal lesions (40, 41).In the present study, 70 patients (40%) underwent preoperative total colonoscopy after stent insertion, with no significant differences evident between older and younger patients (Old, 28.5% vs. Young, 44.4%; p=0.079).
Reports on long-term outcomes in patients undergoing BTS after colorectal stenting are limited (36, 42).However, a multicenter European randomized controlled trial of long-term outcomes in patients undergoing BTS or emergency surgery (36) Indicated that, compared to emergency surgery, BTS did not show significantly better OS [hazard ratio (HR)=0.93,95% confidence interval (CI)=0.49-1.76;p=0.822], disease-free survival (HR=1.01,95%CI=0.56-1.81;p=0.972), or diseasefree survival (HR=1.01,95%CI=0.56-1.81;p=0.972) (36).To the best of our knowledge, no reports have described long-term outcomes after BTS in elderly patients.The present study compared long-term outcomes between elderly and younger patients after propensity score matching, revealing no marked differences between these groups.
Several limitations to this study need to be kept in mind.First, this was a retrospective study.The number of old patients was relatively small and some selection biases might have remained.Second, we excluded patients who could not receive surgery after colonic stenting, and we have no information for those patients.Third, the complication rate associated with stent insertion in this study was low, at only 2.8%.However, the present study did not examine information on fever, tenesmus, or fecal impaction, which have been recorded as complications in previous reports, so complications may have been underestimated in our cohort.In addition, all patients who underwent BTS after colonic stent insertion were enrolled in this study, which may have reflected the favorable results of patients without the complete obstruction seen with CROSS 3 or 4.
Considering these limitations, we believe that BTS after colonic stent insertion for elderly patients represents a potentially useful method for reducing postoperative complications and achieving good long-term results with appropriate case selection.

Table I .
Comparison of clinical characteristics between elderly and young patients with stent insertion.

Table II .
Comparison of perioperative outcomes between elderly and young patients with stent insertion.