Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2010 for the treatment of colorectal cancer

Current status of endoscopic resection strategy for large, early colorectal neoplasia in Japan

BACKGROUND

Conventional endoscopic resection (CER) for early colorectal neoplasia (CRN) is widely accepted as a minimally invasive treatment. Endoscopic submucosal dissection (ESD) was developed in Japan to resect larger lesions, but ESD was not covered by the Japanese national health insurance until April 2012. In addition, treatment strategies vary considerably among medical facilities. To evaluate the current situation in Japan regarding endoscopic treatment of CRNs measuring ≥20 mm, we conducted a prospective multicenter study at 18 medium-volume and high-volume specialized facilities in cooperation with the Japan Society for Cancer of the Colon and Rectum (JSCCR).

METHODS

The JSCCR conducted a multicenter, observational study of all patients treated by CER and ESD of CRNs measuring ≥20 mm.

RESULTS

From October 2007 to December 2010, CERs and ESDs were performed on 1,845 CRNs (CERs 1,029; ESDs 816). Lesions diagnosed as protruded, flat, and depressed totaled 541, 1224, and 48, respectively. En bloc resection rates and mean procedure times for CER/ESD were 56.9%/94.5% (P < 0.01) and 18 ± 23 min/96 ± 69 min, respectively. The average ESD procedure time was 129 ± 83 min in the ≥40-mm group. As lesion size increased, the CER en bloc resection rate decreased significantly (trend P < 0.01), but the ESD en bloc resection rate remained over 93%. Perforation and delayed bleeding rates of CER/ESD were 0.8%/1.6% (P < 0.05) and 2%/2.2% (P = 0.3), respectively.

CONCLUSIONS

The en bloc resection rate for ESD was significantly higher than for CER, although complication rates were fairly low. Despite a longer procedure time, safety of colorectal ESD has improved in various facilities in Japan. However, ESD for lesions measuring ≥40 mm must be performed by experienced endoscopists due to the longer procedure time.

Long-term outcomes after resection for submucosal invasive colorectal cancers

BACKGROUND & AIMS

Little is known about the long-term outcomes of patients with submucosal invasive colorectal cancer who undergo endoscopic or surgical resection. We performed a retrospective analysis of long-term outcomes of patients treated for submucosal colon and rectal cancer.

METHODS

We collected data on 549 patients with submucosal colon cancer and 209 patients with submucosal rectal cancer who underwent endoscopic or surgical resection at 6 institutions over a median follow-up period of 60.5 months. Patients were classified into one of 3 groups: low-risk patients undergoing only endoscopic resection (group A), high-risk patients undergoing only endoscopic resection (group B), and high-risk patients undergoing surgical resection that included lymph node dissection (group C). We assessed recurrence rates, 5-year disease-free survival, and 5-year overall survival. Cox regression analysis was used to compare recurrences.

RESULTS

The rates of recurrence, disease-free survival, and overall survival in group A for submucosal colon and rectal cancer were 0% versus 6.3% (P < .05), 96% versus 90%, and 96% versus 89%, respectively. For group B, these values were 1.4% versus 16.2% (P < .01), 96% versus 77% (P < .01), and 98% versus 96%, respectively; local recurrence was observed in 5 patients (one with submucosal colon cancer and 4 with submucosal rectal cancer). Tumor location was the only factor that contributed significantly to disease recurrence and death (hazard ratio, 6.73; P = .045). For group C, these values were 1.9% versus 4.5%, 97% versus 95%, and 99% versus 97%, respectively.

CONCLUSIONS

The risk for local recurrence was significantly higher in high-risk patients with submucosal rectal cancer than in patients with submucosal colon cancer when treated with only endoscopic resection. The addition of surgery is therefore recommended for patients with submucosal rectal cancer with pathologic features indicating a high risk of tumor progression; University Hospital Medical Network Clinical Trials Registry, Number: UMIN 000008635.

Warning for unprincipled colorectal endoscopic submucosal dissection: accurate diagnosis and reasonable treatment strategy

Piecemeal endoscopic mucosal resection (EMR) is generally indicated for laterally spreading tumors (LST) >2 cm in diameter. However, the segmentation of adenomatous parts does not affect the histopathological diagnosis and completeness of cure. Thus, possible indications for piecemeal EMR are both adenomatous homogenous-type granular-type LST (LST-G) and LST-G as carcinoma in adenoma without segmentalizing the carcinomatous part. Diagnosis of the pit pattern using magnifying endoscopy is essential for determining the correct treatment and setting segmentation borders. In contrast, endoscopic submucosal dissection (ESD) is indicated for lesions requiring endoscopic en bloc excision, as it is difficult to use the snare technique for en bloc excisions such as in non-granular-type LST (LST-NG), especially for the pseudodepressed type, tumors with a type VI pit pattern, shallow invasive submucosal carcinoma, largedepressed tumors and large elevated lesions, which are often malignant (e.g. nodular mixed-type LST-G). Other lesions, such as intramucosal tumor accompanied by submucosal fibrosis, induced by biopsy or peristalsis of the lesion; sporadic localized tumors that occur due to chronic inflammation, including ulcerative colitis; and local residual early carcinoma after endoscopic treatment, are also indications for ESD. In clinical practice, an efficient endoscopic treatment with segregation of ESD from piecemeal EMR should be carried out after a comprehensive evaluation of the completeness of cure, safety, clinical simplicity, and cost-benefit, based on an accurate preoperative diagnosis.

Should isolated peritoneal carcinomatosis from colorectal cancer be sub-classified into stage IVB in era of modern chemotherapy?

BACKGROUND

According to the 7th edition of the TNM staging system, stage IV metastatic colorectal cancer (CRC) at the time of initial diagnosis is sub-classified into stage IVA or IVB disease. Peritoneal carcinomatosis (PC), considered to have a dismal prognosis, is exclusively sub-classified into stage IVB, even though other metastases to a sole organ are sub-classified into stage IVA, which is considered to be associated with better survival. This retrospective study was undertaken to investigate the overall survival in metastatic CRC patients, focusing on PC patients.

METHODS

We reviewed data on patients with metastatic CRC at initial diagnosis surgically treated between January 2006 and June 2011. A survival analysis was performed paying special attention to PC and sub-classifying patients with PC into three categories according to metastatic sites.

RESULTS

There were 69 stage IVA patients (IVA group) and 83 stage IVB. Among stage IVB patients, 20 had isolated PC (PC-I group), 28 had PC with one or more other sites of metastasis (PC-II group), and 35 had at least 2 metastatic without peritoneal involvement (NPC group). Of 152 stage IV patients, 132 (87 %) underwent resection of the primary tumor and 19 (12 %) underwent radical resection of metastatic disease with microscopic free margins (R0 resection) including 5/20 (25 %) patients in the PC1 group. A total of 139 patients received oxaliplatin-based chemotherapy in a palliative (n = 125), neoadjuvant (n = 3), or adjuvant setting after R0 resection (n = 11). Compared with 36.6 months in the PC-I group, median survival was 32.5 months (P = 0.48) in the IVA group, 14.7 months (P = 0.07) in the PC-II group, and 12.9 months (P < 0.01) in the NPC group.

CONCLUSIONS

The sub-classification of isolated PC into stage IVA instead of IVB might be more appropriate in the era of modern chemotherapy. Further investigation is warranted.

Can endoscopic submucosal dissection be safely performed in a smaller specialized clinic?

AIM: To investigate whether endoscopic submucosal dissection (ESD) can be safely performed at small clinics, such as the Shirakawa Clinic.

METHODS: One thousand forty-seven ESDs to treat gastrointestinal tumors were performed at the Shirakawa Clinic from April 2006 to March 2011. The efficacy, technical feasibility and associated complications of the procedures were assessed. The ESD procedures were performed by five endoscopists. Sedation was induced with propofol for esophagogastorduodenal ESD.

RESULTS: One thousand forty-seven ESDs were performed to treat 64 patients with esophageal cancer (E), 850 patients with gastric tumors (G: 764 patients with cancer, 82 patients with adenomas and four others), four patients with duodenal cancer (D) and 129 patients with colorectal tumors (C: 94 patients with cancer, 21 patients with adenomas and 14 others). The en bloc resection rate was 94.3% (E: 96.9%, G: 95.8%, D: 100%, C: 79.8%). The median operation time was 46 min (range: 4-360 min) and the mean size of the resected specimens was 18 mm (range: 2-150 mm). No mortal complications were observed in association with the ESD procedures. Perforation occurred in 12 cases (1.1%, E: 1 case, G: 9 cases, D: 1 case, C: 1 case) and postoperative bleeding occurred in 53 cases (5.1%, G: 51 cases, D: 1 case, C: 1 case); however, no case required either emergency surgery or blood transfusion. All of the perforations and postperative bleedings were resolved by endoscopic clipping or hemostasis. The other problematic complication observed was pneumonia, which was treated with conservative therapy.

CONCLUSION: ESD can be safely performed in a clinic with established therapeutic methods and medical services to address potential complications.

Optimal schedule of adjuvant chemotherapy with S-1 for stage III colon cancer: study protocol for a randomized controlled trial

BACKGROUND

Although, in Western countries, oxaliplatin-based regimens have been established as a gold standard treatment for patients with stage III or high risk stage II colon cancer after curative resection, in Japan fluorouracil-based regimens have been widely accepted and recommended in the guidelines for adjuvant settings in patients with stage III colon cancer. S-1, an oral preparation evolved from uracil and tegafur, has equivalent efficacy to uracil and tegafur/leucovorin for treating patients with advanced colorectal cancer and might be a suitable regimen in an adjuvant setting. However, the completion rate of the standard six-week cycle of the S-1 regimen is poor and the establishment of an optimal treatment schedule is critical. Therefore, we will conduct a multicenter randomized phase II trial to compare six-week and three-week cycles to establish the optimal schedule of S-1 adjuvant therapy for patients with stage III colon cancer after curative resection.

METHODS/DESIGN

The study is an open-label, multicenter randomized phase II trial. The primary endpoint of this study is three-year disease-free survival rate. Secondary endpoints are the completion rate of the treatment, relative dose intensity, overall survival, disease-free survival, and incidence of adverse events. The sample size was 200, determined with a significance level of 0.20, power of 0.80, and non-inferiority margin of a 10% absolute difference in the primary endpoint.

DISCUSSION

Although S-1 has not been approved yet as a standard treatment of colon cancer in an adjuvant setting, it is a promising option. Moreover, in Japan S-1 is a standard treatment for patients with stage II/III gastric cancer after curative resection and a promising option for patients with colorectal liver metastases in an adjuvant setting. However, a six-week cycle of treatment is not considered to be the best schedule, and some clinicians use a modified schedule, such as a three-week cycle to keep a sufficient dose intensity with few adverse events. Therefore, it will be useful to determine whether a three-week cycle has an equal or greater efficacy and tolerance to side-effects compared with the standard six-week cycle schedule, and thus may be the most suitable treatment schedule for S-1 treatment.

TRIAL REGISTRATION

The University Hospital Medical Information Network (UMIN) Clinical Trials Registry UMIN000006750.

Analysis of the anatomic subsites, gender and age in unresectable advanced colorectal carcinomas in Tochigi, Japan suggests a shift in location towards the right side colon in elderly patients treated with cetuximab

Colorectal cancer is a frequently occurring cancer whose incidence has shown a marked increase in recent years. Additionally, an increase in right side colon in elderly patients has been identified. Therefore, a clinicopathological study was conducted in 49 patients with unresectable advanced colorectal carcinomas to elucidate the association of clinicopathological characteristics and K-ras mutation. Of the 49 patients included in this study, 24 were aged <60 years with a male/female (M/F) ratio of 16/8 and 25 patients were aged ≥60 years with a M/F ratio of 16/9. Of the patients aged ≥65 years, 15 patients were enrolled as controls and the M/F ratio was 9/6. Results revealed that with regard to the subsite of cancer, unresectable advanced colorectal carcinomas developed in the right-sided colon in 13 patients, left-sided colon in 19 patients and rectum in 17 patients. Right-sided colon carcinomas were commonly identified in the elderly patients aged ≥65 years, with a marked tendency in the female patients (P=0.024). Immunostaining was performed for the epidermal growth factor receptor (EGFR) antibody in 40 patients to determine whether the K-ras gene would yield positive results. The mutant K-ras gene was identified in 8 patients (20%) and the frequency was lower compared with that of the normal colorectal carcinomas. Anti-EGFR antibody (cetuximab) is considered to be a molecularly targeted agent for unresectable advanced colorectal carcinomas. The increase in incidence of right-sided colon carcinomas as well as the increase in the number of patients presenting with colorectal carcinomas means this issue should be addressed. Sessile serrated adenoma/polyp (SSA/P) with b-raf mutation and CIMP (CpG island methylator phenotype) abnormality as a precursor lesion of right-sided colon carcinoma is common and since cetuximab refractory wild-type K-ras/mutant b-raf colorectal carcinoma may increase in elderly patients and patients with right-sided colon carcinoma, a simultaneous examination for the K-ras and b-raf gene abnormalities for the treatment of colorectal cancer using anti-EGFR antibody (cetuximab) is crucial. In addition, the multidisciplinary assessments regarding the effect of such treatments is likely to be determined based on cumulative results, such as the duration of patient survival.

Pathological evaluation of gastrointestinal endoscopic submucosal dissection materials based on Japanese guidelines

Endoscopic surgery first started as snare polypectomy and then progressed to endoscopic mucosal resection (EMR). In order to resect a lesion that is more than 2 cm, endoscopic submucosal dissection (ESD) was developed. ESD therapy has now been established and is being used for early stage neoplastic lesions in the stomach, colon, esophagus, larynx and pharynx. In ESD specimens, we deal with relatively small lesions; therefore, more meticulous and precise pathological diagnosis is required compared to that in surgically resected specimens. In addition, we should be expert in the eligibility criteria of the different organs for ESD therapy. Here, we explain the biopsy diagnosis, including the Japanese group classification as well as the Vienna classification, handling the specimen, including fixation, photography, cutting and paraffin embedding, histological type, depth, vascular invasion and evaluation of the surgical margins, based on the latest Japanese guidelines. Japanese histopathology diagnostic criteria for the stomach, colon and esophagus are also described. We also demonstrate some examples of those mentioned above.

Feasibility and potential benefit of preoperative chemotherapy for colorectal liver metastasis (CLM): a single-centered retrospective study

PURPOSES

The benefit of neo-adjuvant chemotherapy for liver-limited metastatic colorectal cancer is still controversial. This study defined the resectability regardless of the size and number of liver metastases, and attempted curative hepatic resection in all cases.

METHODS

Sixty-four patients that tolerated chemotherapy were diagnosed with CLM (colorectal liver metastases) without extrahepatic metastase from January 2007 to November 2010, and received an oxaliplatin-based regimen. This study assessed the resectability after chemotherapy, and the patients were divided in two groups; the resected and unresected group. Sixteen patients underwent hepatic resection without chemotherapy.

RESULTS

Thirty-five patients underwent surgical resection (resected group) and twenty-nine patients were considered unresectable (unresected group). All 35 patients in the resected group safely received oxaliplatin-based chemotherapy safely without serious adverse effects. No serious postoperative complications were observed. The median overall survival (MST) was significantly higher in the resected than in the unresected group (56.93 [95% CI 38.13-75.73] and 25.07 months [95% CI 17.87-32.26], respectively; P < 0.001). The median disease-free survival was 20.2 [95% CI 8.82-31.65] months in the resected group.

CONCLUSION

Preoperative chemotherapy for CLM is well tolerated and does not increase postoperative complications. Curative surgery with preoperative chemotherapy has the potential to improve the overall survival in patients with CLM.

Circulating tumor cells as a potential biomarker in selecting patients for pulmonary metastasectomy from colorectal cancer: report of a case

Pulmonary metastasectomy is indicated for selected patients with metastatic colorectal cancer. A 43-year-old woman presented with solitary pulmonary metastasis from descending colon cancer and pulmonary metastasectomy was performed because of absence of any other active metastasis as well as normal serum carcinoembryonic antigen value. However, she died due to early development of nodal and bone metastases within 6 months after thoracotomy. The presence of circulating tumor cells (CTCs) in the peripheral blood (6 CTCs/7.5 ml) was the only factor to predict such a poor prognosis, suggesting that the CTC test is useful in selecting patients for pulmonary metastasectomy.

Computer-aided colorectal tumor classification in NBI endoscopy using local features

An early detection of colorectal cancer through colorectal endoscopy is important and widely used in hospitals as a standard medical procedure. During colonoscopy, the lesions of colorectal tumors on the colon surface are visually inspected by a Narrow Band Imaging (NBI) zoom-videoendoscope. By using the visual appearance of colorectal tumors in endoscopic images, histological diagnosis is presumed based on classification schemes for NBI magnification findings. In this paper, we report on the performance of a recognition system for classifying NBI images of colorectal tumors into three types (A, B, and C3) based on the NBI magnification findings. To deal with the problem of computer-aided classification of NBI images, we explore a local feature-based recognition method, bag-of-visual-words (BoW), and provide extensive experiments on a variety of technical aspects. The proposed prototype system, used in the experiments, consists of a bag-of-visual-words representation of local features followed by Support Vector Machine (SVM) classifiers. A number of local features are extracted by using sampling schemes such as Difference-of-Gaussians and grid sampling. In addition, in this paper we propose a new combination of local features and sampling schemes. Extensive experiments with varying the parameters for each component are carried out, for the performance of the system is usually affected by those parameters, e.g. the sampling strategy for the local features, the representation of the local feature histograms, the kernel types of the SVM classifiers, the number of classes to be considered, etc. The recognition results are compared in terms of recognition rates, precision/recall, and F-measure for different numbers of visual words. The proposed system achieves a recognition rate of 96% for 10-fold cross validation on a real dataset of 908 NBI images collected during actual colonoscopy, and 93% for a separate test dataset.

Laparoscopic resection for sigmoid and rectosigmoid colon cancer performed by trainees: impact on short-term outcomes and selection of suitable patients

PURPOSE

This study aimed (1) to evaluate the impact of clinical factors, particularly operation by trainees, on the short-term outcomes of laparoscopic resection for sigmoid and rectosigmoid cancer, and (2) to determine patients suitable for operation by trainees.

METHODS

From a prospectively maintained single-institution database, we identified 133 patients who underwent laparoscopic resection for sigmoid or rectosigmoid cancer between 2007 and 2010. Gender, age, body mass index (BMI), previous abdominal surgery, tumor location, tumor size, tumor stage, extent of lymph node dissection, and primary surgeon were evaluated using univariate and multivariate analyses to determine the predictive significance of these variables on surgical outcomes including operative time, blood loss, complication, postoperative stay, and retrieved lymph nodes.

RESULTS

Multivariate analysis showed that location of the tumor in the rectosigmoid (p < 0.001), higher BMI (p < 0.001), operation by trainees (p < 0.001), male gender (p = 0.002), and greater tumor depth (p = 0.011) were independently predictive of longer operative time. Larger tumor size (p = 0.025) and higher BMI (p = 0.040) were independently predictive of greater blood loss. Larger tumor size was also related to longer postoperative stay (p = 0.001) and a greater number of retrieved lymph nodes (p = 0.001).

CONCLUSIONS

This study identified operation by trainees as an independent risk factor for longer operative time but with no negative impact on any of the other outcomes. Female patients with a low BMI, sigmoid cancer, shallow tumor depth, and/or small tumor are suitable for operation by trainees.

Endoscopic submucosal dissection--current success and future directions

More than 10 years have passed since endoscopic submucosal dissection (ESD) was first developed in Japan. ESD enables en bloc complete resection of superficial gastrointestinal neoplasms regardless of the size and location of the lesions. With improvements in techniques and devices, excellent therapeutic results have been achieved despite the inherent technical difficulties of this procedure. ESD aiming for curative treatment can be performed for gastrointestinal neoplasms without risk of lymph node metastasis. Accurate histopathologic examination of the resected specimen is required to determine the risk of lymph node metastasis, for which en bloc resection is beneficial. Owing to the high success rate of en bloc complete resection and accurate histopathologic examination, tumour recurrence rates after ESD are reported to be very low in Japan. Excellent results of ESD in a large number of cases have also been reported from other Asian countries such as South Korea, Taiwan and China. Although scepticism exists among Western clinicians regarding the application of ESD, it is developing slowly and reports indicate promising results in some European countries. With further development of technologies, such as endoscopic robotics, ESD could become the worldwide treatment of choice for early gastrointestinal neoplasms.

Impact of hepatic lymph node metastasis on survival of patients with synchronous resectable or unresectable liver metastases of colorectal cancer

BACKGROUND

The goals of this retrospective study were to comprehensively evaluate the impact of hepatic lymph node (HLN) involvement on survival in patients with synchronous resectable or unresectable liver metastases from colorectal cancer and to highlight how to deal with such cases in the light of recent advances in chemotherapy.

METHODS

The impact of HLN involvement on survival, along with various clinical, pathological, and therapeutic factors, was retrospectively evaluated in 61 patients with synchronous liver metastases from colorectal cancer (resectable, 26; unresectable, 35), undergoing resection of the primary tumor and histopathological evaluation between July 2000 and April 2008.

RESULTS

The proportion with HLN metastasis was 11.5 % in resectable cases and 28.6 % in unresectable cases. On multivariate analysis using the Cox proportional hazards model, HLN metastasis (P < 0.001), along with non-resection of hepatic lesions (P < 0.001), larger metastatic tumor volume (P < 0.001), non-use of oxaliplatin-based chemotherapy (P < 0.001), involvement of 4 or more regional lymph nodes (P < 0.001), and excessive lymphatic invasion (P = 0.02), was identified as an independent risk factor for shorter survival.

CONCLUSIONS

To establish a new therapeutic strategy for synchronous liver metastasis of colorectal cancer, the HLNs should be examined histologically in patients undergoing resection of their primary colon and rectal cancer.

Evaluation of magnifying colonoscopy in the diagnosis of serrated polyps

AIM

To elucidate the colonoscopic features of serrated lesions of the colorectum using magnifying colonoscopy.

METHODS

Broad division of serrated lesions of the colorectum into hyperplastic polyps (HPs), traditional serrated adenomas (TSAs), and sessile serrated adenomas/polyps (SSA/Ps) has been proposed on the basis of recent molecular biological studies. However, few reports have examined the colonoscopic features of these divisions, including magnified colonoscopic findings. This study examined 118 lesions excised in our hospital as suspected serrated lesions after magnified observation between January 2008 and September 2011. Patient characteristics (sex, age), conventional colonoscopic findings (location, size, morphology, color, mucin) and magnified colonoscopic findings (pit pattern diagnosis) were interpreted by five colonoscopists with experience in over 1000 colonoscopies, and were compared with histopathological diagnoses. The pit patterns were categorized according to Kudo's classification, but a more detailed investigation was also performed using the subclassification [type II-Open (type II-O), type II-Long (type II-L), or type IV-Serrated (type IV-S)] proposed by Kimura T and Yamano H.

RESULTS

Lesions comprised 23 HPs (23/118: 19.5%), 39 TSAs (39/118: 33.1%: with cancer in one case), 50 SSA/Ps (50/118: 42.4%: complicated with cancer in three cases), and six others (6/118: 5.1%). We excluded six others, including three regular adenomas, one hamartoma, one inflammatory polyp, and one juvenile polyp for further analysis. Conventional colonoscopy showed that SSA/Ps were characterized as larger in diameter than TSAs and HPs (SSA/P vs HP, 13.62 ± 8.62 mm vs 7.74 ± 3.24 mm, P < 0.001; SSA/Ps vs TSA, 13.62 ± 8.62 mm vs 9.89 ± 5.73 mm, P < 0.01); common in the right side of the colon [HPs, 30.4% (7/23): TSAs, 20.5% (8/39): SSA/P, 84.0% (42/50), P < 0.001]; flat-elevated lesion [HPs, 30.4% (7/23): TSAs, 5.1% (2/39): SSA/Ps, 90.0% (45/50), P < 0.001]; normal-colored or pale imucosa [HPs, 34.8% (8/23): TSAs, 10.3% (4/39): SSA/Ps, 80% (40/50), P < 0.001]; and with large amounts of mucin [HPs, 21.7% (5/23): TSAs, 17.9% (7/39): SSA/Ps, 72.0% (36/50), P < 0.001]. In magnified colonoscopic findings, 17 lesions showed either type II pit pattern alone or partial type II pit pattern as the basic architecture, with 14 HPs (14/17, 70.0%) and 3 SSA/Ps. Magnified colonoscopy showed the type II-O pit pattern as characteristic of SSA/Ps [sensitivity 83.7% (41/49), specificity 85.7% (54/63)]. Cancer was also present in three lesions, in all of which a type VI pit pattern was also present within the same lesion. There were four HPs and four TSAs each. The type IV-S pit pattern was characteristic of TSAs [sensitivity 96.7% (30/31), specificity 89.9% (72/81)]. Cancer was present in one lesion, in which a type VI pit pattern was also present within the same lesion. In our study, serrated lesions of the colorectum also possessed the features described in previous reports of conventional colonoscopic findings. The pit pattern diagnosis using magnifying colonoscopy, particularly magnified colonoscopic findings using subclassifications of surface architecture, reflected the pathological characteristics of SSA/Ps and TSAs, and will be useful for colonoscopic diagnosis.

CONCLUSION

We suggest that this system could be a good diagnostic tool for SSA/Ps using magnifying colonoscopy.

S-1 for the treatment of gastrointestinal cancer

INTRODUCTION

5-Fluorouracil (5-FU)-based regimens are used worldwide as the standard treatment in chemotherapy for gastric cancer. S-1 , a fourth-generation oral fluoropyrimidine that combines tegafur and two biochemical modulators: gimeracil and oteracil potassium, is now attracting considerable interest.

AREAS COVERED

This review addresses the clinical evidence of S-1 in gastrointestinal malignancies, such as gastric, colorectal, pancreatic and biliary tract cancers. S-1 has demonstrated advantages over standard therapies, in both advanced and postoperative settings, in large Phase III studies. S-1 alone or S-1 plus cisplatin is recommended in the 2010 Gastric Cancer Treatment Guidelines, by the Japanese Gastric Cancer Association. Results from Phase III studies have demonstrated that S-1 in combination with chemotherapies, such as cisplatin in gastric cancer, and irinotecan and oxaliplatin in colorectal cancers, is non-inferior to conventional 5-FU-based standard regimens, with the benefit of convenience and reduced toxicity.

EXPERT OPINION

The excellent design of S-1 aimed to reduce toxicity by avoiding certain routes of degradation, and to enhance activity by reducing catabolism. This has provided not only a suitable alternative to 5-FU, but also higher efficacy.

Laparoscopic-assisted colectomy in a patient with colon cancer after percutaneous endoscopic gastrostomy

BACKGROUND

A number of patients undergo percutaneous endoscopic gastrostomy (PEG) under various conditions. Open colectomy is usually performed for colon cancer in patients with PEG because the safety of the laparoscopic approach for such patients has not been established. However, if the laparoscopic approach is possible in patients with PEG, it will be less invasive and more helpful in rehabilitation into society.

CASE PRESENTATION

We describe the case of a 64-year-old male with a T1 adenocarcinoma of the ascending colon 2 years after surgery for nasal cancer and PEG for dysphagia. The patient did not have any distant metastases or malignant tumors on preoperative computed tomography and positron-emission tomography. He underwent laparoscopic-assisted colectomy (LAC) with lymph node dissection. No complications developed during or after the surgery.

CONCLUSIONS

LAC could be a potential option for the treatment of colon cancer in patients who have undergone PEG. To our knowledge, this is the first recorded case of an ascending colon cancer treated with LAC under the condition of gastrostoma.

Chemotherapy and molecular-targeted treatment for unresectable hepatic metastases: a Japanese perspective

Liver metastasis from colorectal cancer has become a common disease associated with the increase of primary colorectal cancer in Japan. The standard treatment for resectable liver metastases is still complete liver resection. Recent advances in systemic chemotherapy have introduced another strategy, i.e., conversion chemotherapy, for patients with initially diagnosed unresectable liver metastases. The conversion rate after neo-adjuvant chemotherapy is increasing with multidisciplinary approaches. Long-term clinical data have not been established yet. Indications for liver resection after neo-adjuvant chemotherapy; optimal chemotherapy regimens; and histological changes in the normal liver are important research issues for the future.

[Principles and technique of lymph node dissection in colorectal carcinoma]

Colorectal carcinoma is a common malignant tumor which shows a standard behavior for lymphogenic metastasis. Depending on the localization of the primary tumor the corresponding lymphatic area also has to be removed because lymph node metastases can already be present by every tumor even if there is no obvious intraoperative evidence. Lymphatic drainage is essentially oriented to the supplying arteries of the corresponding intestinal segment. The anatomy of arterial supply is individually variable and often deviates from the usual textbook presentation. In this review the oncological requirements of an adequate lymph node dissection in colorectal carcinoma are described with emphasis on the technical aspects to obtain an optimal specimen.

Indication, strategy and outcomes of endoscopic submucosal dissection for colorectal neoplasm

Although endoscopic submucosal dissection (ESD) for colorectal neoplasm is a promising endoscopic therapy with a high rate of successful en bloc resection, ESD for colorectal neoplasm is not a health-care service provided by Japanese public heath insurance, yet. Now, ESD for colorectal neoplasm has been approved as an 'advanced medical treatment' system, which is a partial-care service provided by Japanese public health insurance with individual payment of medical expenses, and the indication for ESD for colorectal neoplasm has been under debate. In our hospital, a total of 348 colorectal neoplasms underwent ESD using the FlexKnife and the FlushKnife, and 317 lesions (91%) were resected en bloc. Perforation occurred in eight cases (2%) and they were not critical and did not require emergent surgery. Delayed bleeding occurred in 16 cases (4%) and they were able to be controlled without transfusion and were not critical. The major impact of the advanced medical treatment system on clinical practice in our hospital was the increased incidence of adenocarcinoma and increased tumor size in the lesions that underwent ESD. It is thought that the application of the advanced medical treatment system resulted in careful selection of lesions for ESD while maintaining the principle of en bloc resection. We expect that a new, revised indication that covers recurrent carcinoma after endoscopic therapy will be indicated when ESD for colorectal neoplasm becomes a health-care service provided by Japanese public health insurance.

Postoperative chylous ascites after colorectal cancer surgery

PURPOSE

To evaluate the diagnosis, epidemiology, risk factors, and treatment of chylous ascites after colorectal cancer surgery.

METHODS

Among 907 patients who underwent colorectal cancer resection at our institution between 2006 and 2009, chylous ascites developed in 9. We analyzed the clinical data for these 9 patients.

RESULTS

Five of the nine patients with chylous ascites had undergone right hemicolectomy and seven had undergone D3 lymph node dissection. In all patients, chylous ascites began to develop the day after commencement of oral intake or the next day. Two patients had no change in diet, one was started on a high-protein and low-fat diet, and six were put on intestinal fasting. Drainage tubes were removed within 5 days after treatment in seven patients. The hospital stay was about 2 weeks after surgery and 1 week after treatment. We found that the tumor area, tumors fed by the superior mesenteric artery, and D3 lymph node dissection were significantly associated with chylous ascites.

CONCLUSIONS

Chylous ascites after colorectal cancer surgery occurred at an incidence of 1.0%, but was significantly more frequent after surgery for tumors fed by the superior mesenteric artery and after D3 lymph node dissection. Conservative treatment was effective in all cases.

Anal function-preserving subtotal intersphincteric resection/partial external sphincteric resection with hybrid 2-port hand-assisted laparoscopic surgery (Mukai's operation) for very low stage I rectal cancer: A case report

A 62-year-old male patient underwent endoscopic mucosal resection (EMR). Additional hybrid 2-port hand-assisted laparoscopic surgery (HALS) (Mukai's operation) was performed for early rectal cancer located at the distal border of the rectum/below the peritoneal reflection (Rb) region [SM massive invasion/ly+/vertical margin (VM)X] via a small transverse incision, approximately 55 mm long, at the superior border of the pubic bone. After the pelvic floor muscles were dissected by laparoscopy-assisted manipulation, transanal subtotal intersphincteric resection (ISR) was performed under direct vision, securing a margin of more than 15 mm distal to the EMR scar. Partial external sphincteric resection (ESR) was also performed to obtain an adequate VM at the posterior region of the EMR scar. After bowel reconstruction, the layers were sutured transanally and a temporary covering colostomy was created. The resected specimen contained no residual tumor cells without lymph node metastasis. At 3 months after the operation, digital examination revealed good tonus of the anal muscles without stricture. The patient is currently undergoing rehabilitation of his anal sphincter muscles in preparation for the colostomy closure. In conclusion, subtotal ISR combined with partial ESR may decrease the need to perform Miles' operation for T1/2 stage I rectal cancer located at the distal border of the Rb region.