Effect of Preoperative Colonic Drainage for Obstructing Colorectal Cancer

Between January 2001 and December 2011, a total of 879 consecutive stage I–IV colorectal cancer patients underwent colectomy for primary histologically proven colorectal carcinoma at the Department of Digestive Surgery, Nihon University School of Medicine Itabashi Hospital.

Among these 879 patients, those with T1 or T2 carcinoma were excluded from the present study as none of them presented with large bowel obstruction at the time of diagnosis, leaving a total of 656 patients eligible for inclusion. Moreover, laparoscopic surgery is performed in patients with T1 or T2 stage disease at our hospital. Therefore, no such cases were included in this study.

The patients were divided into 2 groups: an advanced OCRC group (OCRC), which included 104 patients undergoing colectomy with preoperative colonic decompression, and a nonobstructing advanced CRC group (CRC), which included 552 patients undergoing colectomy alone. The colon was divided into left and right segments at the junction of the transverse and descending colon. Each patient was assessed by medical history, physical examination, abdominal X-ray, and abdominal computed tomography. When OCRC was diagnosed, gastrografin enema and urgent decompression therapy were carried out within 24 hours of admission. The data on tumor distribution, main and concomitant surgery, TNM stage, and histopathology were recorded. This study including data analysis and statistical analysis was approved by the Research review board, Nihon University School of Medicine, Itabashi Hospital (No RK-120511).

Preoperative decompression was performed in all OCRC patients in line with the treatment policy of our department. Decompression was performed by insertion of a nasogastric decompression tube via the right segment or a transanal decompression tube via the colon proximal to the tumor using a colonoscope and guide wire in the left segment. Decompression by colostomy was performed when no improvement was observed with either of these conservative treatments. Metallic stent insertion was not covered by the national insurance system in Japan until 2011. Therefore, this procedure was not used in any of the present cases. The timing of surgery and procedures used in all patients were in line with the policy of this institute. The rate of hospital deaths, defined as death during the period of hospitalization due to the surgical procedures used or any other cause within 30 days postoperatively, and surgery-related complications were calculated by dividing the number of patients in whom an event occurred by the total number of enrolled patients. Chemoradiotherapy has yet to be recognized as the standard treatment for rectal cancer in Japan. Therefore, this type of therapy was not included in the present study.

Correlations between overall survival (OS) curves in the 2 groups were determined by the Kaplan-Meier method. Prognostic factors were analyzed by univariate analysis and logistic regression. The statistical significance of differences in survival curves was assessed with a 2-sided log rank test. A P value of less than 0.05 was considered to indicate statistical significance. The SAS software package for Windows, version 8.02 (SAS Institute Inc, Cary, NC, USA) and Microsoft Excel 2003 (Microsoft Co, Ltd, Tokyo, Japan) were used for the statistical analysis and data calculation. Data were entered into a prospectively managed database at the time of treatment. We retrospectively reviewed records from this database. The data used for this study were from the last follow-up visit or contact with the patients.

Patient characteristics and clinical and pathological stage are shown in Table 1. Nasointestinal decompression was performed in 42 patients (40.4%); transanal decompression in 15 patients (14.4%); and decompression by colostomy in 47 patients (45.2%). Median hospital stay was 11 days longer in the OCRC group than that in the CRC group (39 days versus 28 days, respectively; P = 0.0001). Median preoperative days, however, was 7 days shorter in the OCRC group than that in the CRC group (21 days versus 28 days, respectively; P = 0.058). The surgical findings are shown in Table 2. More patients required 2-stage resection in the OCRC group than in the CRC group (P = 0.0001). Median operation time in the OCRC group was 240 min, which was 12 minutes longer than that in the CRC group (P = 0.001). Histopathologic findings are shown in Table 3. A greater percentage of patients showed T4 or N2 in the OCRC group than in the CRC group (P = 0.0001). Operative complications are shown in Table 4. Overall incidence of surgery-related complications was 46.2% in the OCRC group (48 of 104 patients) and 36.6% in the CRC group (202 of 552 patients). None of these differences was statistically significant (P = 0.066). Rate of hospital death was 0.0% in the OCRC group and 0.6% in the CRC group. Obstructing colorectal carcinoma was not identified as an independent prognostic factor (Table 5). Figure 1 shows the OS rates for patients in each group. The 5-year OS rate was 71.9% in the OCRC group and 72.0% in the CRC group [hazard ratio 0.926; 95% confidence interval (CI), 0.575 to 1.581; P = 0.77]. Figures 2, 3, and 4 show the OS rates in 244, 196, and 158 patients with stages II, III, and IV tumor, respectively, in both groups. The 5-year OS rate of stage II was 87.1% in the OCRC group and 85.4% in the CRC group (hazard ratio 1.072; 95% CI, 0.314 to 6.701; P = 0.93); that of stage III was 81.2% in the OCRC group and 76.0% in the CRC group (hazard ratio 1.156; 95% CI, 0.482 to 3.423; P = 0.77); and that of stage IV was 41.6% in the OCRC group and 42.2% in the CRC group (hazard ratio 1.009; 95% CI, 0.548 to 2.038; P = 0.98). No statistically significant differences were observed in survival between the two groups in stage II, III, IV, or overall.

Obstructing CRC is believed to indicate poorer long-term survival than non-obstructing CRC. In this study, however, preoperative colonic decompression in OCRC yielded no difference in safety or prognosis between the 2 groups. Currently, postoperative adjuvant chemotherapy is indicated in the NCCI guidelines (Version 3.2013 Colon Cancer) for the treatment of stage II colon cancer when the prognosis is poor, and OCRC is included in this category. Preoperative colonic decompression, however, may allow OCRC to be excluded from this group.

Many studies have noted that OCRC is either locally advanced or associated with distant metastases.^8,9,12,13  In this study, however, distribution of TNM stage and rate of residual tumor after decompression surgery were similar between the 2 groups, indicating no association between OCRC and distant metastasis in patients undergoing colectomy for primary colorectal cancer. There is a possible association between OCRC and aging. Such patients are often older than CRC patients and have increased risk factors due to hypovolemia and electrolytic alterations.¹⁴  In this study, however, age was similar between the 2 groups, indicating no association between OCRC and age.

One study noted that long-term outcome in OCRC was worse than that in CRC due to the lower rate of emergency curative resection in the former group.¹⁵  Moreover, colonic distension and fecal loading can make the surgical procedure more technically demanding in patients with OCRC. It is possible that the choice of surgery is the reason for the poor prognosis in OCRC patients. One-stage surgery with primary resection and anastomosis is performed in the majority of patients with OCRC.¹⁶  While primary resection and ileocolic anastomosis at initial surgery is the generally accepted approach in right-sided OCRC, primary resection and colon anastomosis has been suggested as the best oncologic approach in left-sided OCRC.^8–10  Operative mortality after primary colonic resection in emergency cases, however, has been reported to range from 23% to 50%.^8,13  The high rates of morbidity and hospital mortality seen with 1-stage surgery may be associated with a low rate of curative resection and worse prognosis in OCRC. In this study, preoperative colonic decompression in OCRC patients yielded no mortalities and a low rate of morbidity, results comparable with those for CRC. This suggests that the problems usually associated with the treatment of OCRC might be avoided by use of preoperative decompression.

One study found that preoperative colonic decompression using a transanal ileus tube was safe and that there was no increase in complications or anastomotic leakage in one-stage surgery for left segment OCRC.¹⁶  In this study, if peritonitis developed or there was no improvement in obstruction by conservative treatment with nasointestinal or transanal decompression within 3 days, a colostomy was performed. However, the success rate in conservative decompression using nasointestinal or transanal decompression was 86.7% (26 of 30 patients) in the right segment and 41.9% (31 of 74 patients) in the left segment. Among the present cases, 45.2% required a colostomy as second- or third-stage surgery. Although an increase of 10 days in length of hospital stay was observed in the OCRC group in comparison with in the CRC group, we believe that the improvements obtained in safety and prognosis vindicate the use of preoperative decompression in such patients. Recent studies have indicated that colonic self-expanding metallic stents may provide prompt relief in OCRC, and such stents are now increasingly being used in either a palliative setting or as a bridge to surgery in patients in whom a definitive surgical approach is unsuitable.^18–20  Therefore, this procedure was not used in any of the present cases. While colonic self-expanding metallic stents may offer an effective treatment option in patients with OCRC, however, it has also been reported that stent placement for OCRC was associated with the risk of recurrence.²¹  Therefore, the efficacy of colonic self-expanding metallic stents remains controversial.

In conclusion, in this study, preoperative colonic decompression in advanced OCRC patients was associated with low mortality and reasonable survival time, indicating the validity of this approach, providing the institution concerned has sufficient experience with the procedures and postoperative management required. The results also suggest that use of preoperative decompression can yield a marked reduction in risk in advanced OCRC, thus improving its prognosis.

This work was mainly supported by a Grant-in-Aid for Scientific Research (A) 24249068 from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.