Histological differentiation between sporadic and colitis-associated intestinal cancer in a nationwide study: A propensity-score-matched analysis.

BACKGROUND AND AIM: Colitis-associated intestinal cancer (CAC) can develop in patients with inflammatory bowel disease; however, the malignant grade of CAC may differ from that of sporadic colorectal cancer (CRC). Therefore, we compared histological findings distinct from cancer stage between CAC and sporadic CRC to evaluate the features of CAC. METHODS: We reviewed the clinical and histological data collected from a nationwide database in Japan between 1983 and 2020. Patient characteristics were compared to distinguish ulcerative colitis (UC), Crohn's disease (CD), and sporadic CRC. Comparisons were performed by using all collected data and propensity score-matched data. RESULTS: A total of 1077 patients with UC-CAC, 297 with CD-CAC, and 136 927 with sporadic CRC were included. Although the prevalence of well or moderately differentiated adenocarcinoma (Tub1 and Tub2) decreased according to tumor progression for all diseases (P < 0.01), the prevalence of other histological findings, including signet ring cell carcinoma, mucinous carcinoma, poorly differentiated adenocarcinoma, or squamous cell carcinoma, was significantly higher in CAC than in sporadic CRC. Based on propensity score-matched data for 982 patients with UC and 268 with CD, the prevalence of histological findings other than Tub1 and Tub2 was also significantly higher in those with CAC. At pT4, mucinous carcinoma occurred at a significantly higher rate in patients with CD (45/86 [52.3%]) than in those with sporadic CRC (13/88 [14.8%]) (P < 0.01). CONCLUSION: CAC, including early-stage CAC, has a higher malignant grade than sporadic CRC, and this difference increases in significance with tumor progression.

Crohn's Disease-Associated Anorectal Cancer Has a Poor Prognosis With High Local Recurrence: A Subanalysis of the Nationwide Japanese Study.

INTRODUCTION: Colorectal cancer (CRC) is one of the major life-threatening complications in patients with Crohn's disease (CD). Previous studies of CD-associated CRC (CD-CRC) have involved only small numbers of patients, and no large series have been reported from Asia. The aim of this study was to clarify the prognosis and clinicopathological features of CD-CRC compared with sporadic CRC. METHODS: A large nationwide database was used to identify patients with CD-CRC (n = 233) and sporadic CRC (n = 129,783) over a 40-year period, from 1980 to 2020. Five-year overall survival (OS), recurrence-free survival (RFS), and clinicopathological characteristics were investigated. The prognosis of CD-CRC was further evaluated in groups divided by colon cancer and anorectal cancer (RC). Multivariable Cox regression analysis was used to adjust for confounding by unbalanced covariables. RESULTS: Compared with sporadic cases, patients with CD-CRC were younger; more often had RC, multiple lesions, and mucinous adenocarcinoma; and had lower R0 resection rates. Five-year OS was worse for CD-CRC than for sporadic CRC (53.99% vs 71.17%, P < 0.001). Multivariable Cox regression analysis revealed that CD was associated with significantly poorer survival (hazard ratio 2.36, 95% confidence interval: 1.54-3.62, P < 0.0001). Evaluation by tumor location showed significantly worse 5-year OS and RFS of CD-RC compared with sporadic RC. Recurrence was identified in 39.57% of CD-RC cases and was mostly local. DISCUSSION: Poor prognosis of CD-CRC is attributable primarily to RC and high local recurrence. Local control is indispensable to improving prognosis.

Effect of Biologics on the Risk of Advanced-Stage Inflammatory Bowel Disease-Associated Intestinal Cancer: A Nationwide Study.

INTRODUCTION: The aim of this study was to evaluate the effect of biologics on the risk of advanced-stage inflammatory bowel disease (IBD)-associated intestinal cancer from a nationwide multicenter data set. METHODS: The medical records of patients with Crohn's disease (CD) and ulcerative colitis (UC) diagnosed with IBD-associated intestinal neoplasia (dysplasia or cancer) from 1983 to 2020 were included in this study. Therapeutic agents were classified into 3 types: biologics, 5-aminosalicylic acid, and immunomodulators. The pathological cancer stage was compared based on the drug used in both patients with CD and UC. RESULTS: In total, 1,042 patients (214 CD and 828 UC patients) were included. None of the drugs were significantly associated with cancer stage in the patients with CD. In the patients with UC, an advanced cancer stage was significantly associated with less use of biologics (early stage: 7.7% vs advanced stage: 2.0%, P < 0.001), 5-aminosalicylic acid, and immunomodulators. Biologic use was associated with a lower incidence of advanced-stage cancer in patients diagnosed by regular surveillance (biologics [-] 24.5% vs [+] 9.1%, P = 0.043), but this was not the case for the other drugs. Multivariate analysis showed that biologic use was significantly associated with a lower risk of advanced-stage disease (odds ratio = 0.111 [95% confidence interval, 0.034-0.356], P < 0.001). DISCUSSION: Biologic use was associated with a lower risk of advanced IBD-associated cancer in patients with UC but not with CD. The mechanism of cancer progression between UC and CD may be different and needs to be further investigated.

[A Case of Descending Colon Cancer with Distant Metastasis That Was Controlled Severe Side Effects of Chemotherapy and Achieved Long-Term CR].

A 69-year-old male patient with descending colon cancer with para-aortic lymph node metastasis underwent surgery to resect the primary tumor. After the surgery mFOLFOX6 plus panitumumab was introduced. Because 2 times drug-induced lung disease and Stevens Johnson syndrome were occurred, changes in chemotherapy regimen were required. 18 months after administration, complete response was achieved. The chemotherapy was discontinued 48 months after administration. He is alive without recurrence for 32 months after completion of treatment.

Closure of enterotomy after side-to-side ileocolic anastomosis with two barbed sutures in totally laparoscopic colectomy for right-sided colon cancer.

Good short-term outcomes of intracorporeal ileocolic anastomosis (IIA) in totally laparoscopic colectomy for right-sided colon cancer (TLRC) have been shown in many reports, but no standardized technique for enterotomy closure after stapled side-to-side ileocolic anastomosis has so far been established. We retrospectively compared the short-term outcomes between 13 consecutive patients receiving either TLRC with IIA by conventional enterotomy closure (n = 6) or closure of the enterotomy using two barbed sutures (CEBAS) (n = 7) from July 2019 to April 2020. No anastomotic bleeding or leakage was observed in either group. Time to enterotomy closure was significantly shorter with the CEBAS method (16.5 ± 3.7 min) than with the conventional method (24.5 ± 4.7 min, p = 0.0059). The CEBAS method in TLRC with IIA was thus found to be technically feasible and it might reduce the stress associated with intracorporeal enterotomy closure.

Male sex and anterior wall tumor location as risk factors for urinary dysfunction after laparoscopic rectal surgery.

BACKGROUND: Total mesorectal excision (TME) has decreased the local recurrence rate and improved the overall survival of rectal cancer patients. However, urinary dysfunction remains a clinical problem after rectal cancer surgery. The aim was to assess the risk factors for postoperative urinary dysfunction. METHODS: This study was a single-center, retrospective analysis of 104 patients who underwent laparoscopic rectal surgery between November 2016 and October 2017. Postoperative urinary dysfunction was defined as the need for urinary catheter re-insertion or the presence of residual urine (≥ 150 mL) postoperatively. RESULTS: Postoperative urinary dysfunction was seen in 18 patients (17%). Multivariate analysis showed that male sex (odds ratio 3.89, p = 0.034) and anterior wall tumor location (odds ratio = 4.07, p = 0.037) were the predictors of postoperative urinary dysfunction. Compared with patients without risk factors, those with the two risk factors needed longer hospital stays (16 days vs. 30 days, p = 0.0022). CONCLUSION: Male sex and anterior wall tumor location were the risk factors for urinary dysfunction after laparoscopic rectal surgery.

The Management of Recurrence within Six Months after Hepatic Resection for Colorectal Liver Metastasis.

BACKGROUND: Hepatectomy is currently recommended as the most reliable treatment for colorectal liver metastases. However, the association between the choice of treatment for recurrence and the timing of recurrence remains controversial. METHODS: Two-hundred ninety-five patients who underwent hepatectomy were retrospectively analyzed for the risk factors and the outcomes for early recurrence within 6 months. The remnant liver volumes (RLVs) and laboratory data were measured postoperatively using multidetector computed tomography on days 7 and months 1, 2, and 5 after the operation. RESULTS: Early recurrence developed in 88/295 patients (29.8%). Colorectal cancer lymph node metastasis, synchronous liver metastasis, and multiple liver metastases were independent risk factors for the occurrence of early recurrence (p < 0.001, 0.032, and 0.019, respectively). Patients with early recurrence had a poorer prognosis than did patients who developed later recurrence (p < 0.001). Patients who underwent surgery or other local treatment had better outcomes. The changes in RLV and laboratory data after postoperative month 2 were not significantly different between the 2 groups. CONCLUSION: Patients with early recurrence within 6 months had a poorer prognosis than did patients who developed later recurrence. However, patients who underwent repeat hepatectomy for recurrence had a better prognosis than did those who underwent other treatments, with good prospects for long-term survival.

Delta-like 3 localizes to neuroendocrine cells and plays a pivotal role in gastrointestinal neuroendocrine malignancy.

Delta-like 3 (DLL3) is a member of the Delta/Serrate/Lag2 (DSL) group of Notch receptor ligands. Five DSL ligands are known in mammals, among which DLL3 has a unique structure. In the last few years, DLL3 has attracted attention as a novel molecular targeting gene in neuroendocrine carcinoma of the lung due to its high expression. However, the expression pattern and functions of DLL3 in the gastrointestinal tract and gastrointestinal neuroendocrine carcinoma remain unclear. In this study, we examined the expression and role of DLL3 in the gastrointestinal tract, as well as in gastrointestinal neuroendocrine carcinoma. Immunohistochemical staining of the human normal gastrointestinal tract revealed that DLL3 localized in neuroendocrine cells. DLL3 showed intense staining in chromogranin A-positive gastric cancer specimens. Real-time quantitative RT-PCR and western blotting analyses showed considerable upregulation of DLL3 in gastrointestinal neuroendocrine carcinoma cell lines. Immuno-electron microscopy demonstrated abundant expression of DLL3 in neurosecretory granules in these cells. Furthermore, gene silencing of DLL3 caused significant growth inhibition through the induction of intrinsic apoptosis. Our findings suggest that DLL3 is expressed in neuroendocrine cells of the gastrointestinal tract and that it has a pivotal role in gastrointestinal neuroendocrine carcinoma cells. Based on these findings, further investigations are required to achieve a breakthrough in developing therapeutic strategies for gastrointestinal neuroendocrine carcinoma.

Clinical impact of single-incision laparoscopic right hemicolectomy with intracorporeal resection for advanced colon cancer: propensity score matching analysis.

BACKGROUND: Laparoscopic right hemicolectomy has become an acceptable treatment for right-sided colon cancer. Most centers use multiport laparoscopic right hemicolectomy extracorporeally (MRHE), whereas single-incision laparoscopic right hemicolectomy intracorporeally (SRHI) remains controversial. The aim of this study was to compare these two techniques using propensity score matching analysis. METHODS: We analyzed the data from 111 patients who underwent laparoscopic right hemicolectomy between December 2015 and December 2016. The propensity score was calculated according to age, gender, body mass index, the American Society of Anesthesiologists score, previous abdominal surgery, and D3 lymph node dissection. Postoperative pain was evaluated using a visual analogue scale (VAS) and postoperative analgesic use was an outcome measure. RESULTS: The length of skin incision in SRHI was significantly shorter than in MRHE [3 (3.5-6) versus 4 (3-6) cm, respectively; P = 0.007]. The VAS score on day 1 and day 2 after surgery was significantly less in SRHI than in MRHE [30 (10-50) versus 50 (20-69) on day 1, P = 0.037; 10 (0-50) versus 30 (0-70) on day 2, P = 0.029]. Significantly fewer patients required analgesia after SRHI on day 1 and day 2 after surgery [1 (0-3) versus 2 (0-4) on day 1, P = 0.024; 1 (0-2) versus 1 (0-4) on day 2, P = 0.035]. There were no significant differences in operative time, intraoperative blood loss, number of lymph nodes removed, and postoperative course between groups. CONCLUSIONS: SRHI appears to be safe and technically feasible. Moreover, SRHI reduces the length of the skin incision and postoperative pain compared with MRHE.

Totally extraperitoneal approach to laparoscopic lateral lymph node dissection for patients with recurrent lateral pelvic lymph nodes after rectal cancer surgery: a novel technique-M TEP LLND.

Lateral lymph node dissection (LLND) for recurrence of lateral pelvic lymph node metastasis after rectal cancer surgery is technically demanding because of the need for re-do surgery. We herein report a novel technique of laparoscopic LLND via a totally extraperitoneal (TEP) approach. Since October 2018, we have performed LLND based on a TEP approach, called "M TEP LLND", with two cases treated. By peeling in the caudal direction in the dorsal layer of the rectus abdominis muscle, a working space is created once the extraperitoneal space is reached, and LLND is performed. All lateral pelvic lymph node dissection procedures have been successfully completed, and there have been no intraoperative or postoperative complications. This procedure allows TEP-experienced colorectal surgeons to perform safe and complete LLND without any influence of intraperitoneal adhesion or intestinal obstruction. M TEP LLND is less invasive than the conventional intraperitoneal approach and appears to be useful, particularly for recurrence of lateral pelvic lymph node metastasis.

A Concealed "Natural Orifice": Umbilicus Anatomy for Minimally Invasive Surgery.

INTRODUCTION: A recent development in minimally invasive surgery (MIS) is single-port surgery, where a single large multiport trocar is placed in the umbilicus. All medical schools require that students complete an anatomy course as part of the medical curriculum. However, there is limited instruction regarding the detailed parts of the "umbilicus." In several famous anatomy atlases, the umbilicus is not dissected at all and is merely represented as a button. Until now, the true nature of the umbilicus has not been anatomically demonstrated. METHODS: Five cadavers were obtained from the Osaka Medical College medical student anatomy class. The umbilicus was dissected in the anatomy laboratory, to demonstrate all the layers. A detailed dissection was performed, focusing on the exact center of the umbilicus, in order to ascertain whether there exists a "natural orifice" or a fascial defect. RESULTS: In all cadavers, a small defect of fascia was identified just below the center of the umbilicus. Yellow fatty tissue was present just below the skin in the exact center of the umbilicus. A probe placed exactly in the middle of this defect passes easily through into the abdominal cavity. CONCLUSIONS: With the widespread use of MIS, umbilical incision is commonly used to reduce pain and improve cosmetic results. This study consistently revealed a natural defect of fascia in the center of the umbilicus. Therefore, the umbilicus can be called a concealed "natural orifice." It is important to recognize and utilize this defect effectively to minimize unnecessary tissue trauma during MIS.

Nogo-B (Reticulon-4B) functions as a negative regulator of the apoptotic pathway through the interaction with c-FLIP in colorectal cancer cells.

Nogo-B is a member of the Nogo/Reticulon-4 family and has been reported to be an inducer of apoptosis in certain types of cancer cells. However, the role of Nogo-B in human cancer remains less understood. Here, we demonstrated the functions of Nogo-B in colorectal cancer cells. In clinical colorectal cancer specimens, Nogo-B was obviously overexpressed, as determined by immunohistochemistry; and Western blot analysis showed its expression level to be significantly up-regulated. Furthermore, knockdown of Nogo-B in two colorectal cancer cell lines, SW480 and DLD-1, by transfection with si-RNA (siR) resulted in significantly reduced cell viability and a dramatic increase in apoptosis with insistent overexpression of cleaved caspase-8 and cleaved PARP. The transfection with Nogo-B plasmid cancelled that apoptosis induced by siRNogoB in SW480 cells. Besides, combinatory treatment with siR-Nogo-B/staurosporine (STS) or siR-Nogo-B/Fas ligand (FasL) synergistically reduced cell viability and increased the expression of apoptotic signaling proteins in colorectal cancer cells. These results strongly support our contention that Nogo-B most likely played an oncogenic role in colorectal cancer cells, mainly by negatively regulating the extrinsic apoptotic pathway in them. Finally, we revealed that suppression of Nogo-B caused down-regulation of c-FLIP, known as a major anti-apoptotic protein, and activation of caspase-8 in the death receptor pathway. Interaction between Nogo-B and c-FLIP was shown by immunoprecipitation and immunofluorescence studies. In conclusion, Nogo-B was shown to play an important negative role in apoptotic signaling through its interaction with c-FLIP in colorectal cancer cells, and may thus become a novel therapeutic target for colorectal cancer.

Peranal endoscopic myectomy (PAEM) for rectal lesions with severe fibrosis and exhibiting the muscle-retracting sign.

BACKGROUND: Although endoscopic submucosal dissection has enabled complete tumor resection and accurate pathological assessment in a manner that is less invasive than surgery, the complete resection of lesions with severe fibrosis in the submucosal layer and exhibiting the muscle-retracting sign is often difficult. We have devised a new method, peranal endoscopic myectomy (PAEM), for rectal lesions with severe fibrosis, in which dissection is performed between the inner circular and outer longitudinal muscles, and have examined the usefulness and safety of this new technique. METHODS: All of the patients who underwent PAEM in our hospital and affiliated hospitals between July 2015 and June 2017 were retrospectively reviewed. RESULTS: 10 rectal lesions were treated with PAEM. En bloc resection with a negative vertical margin was achieved in eight patients (80 %), whose lesions were mucosal (n = 2), shallow submucosal (n = 1), deep submucosal (n = 4), and muscle invasive (n = 1). The clinical course of all patients after PAEM was favorable. In patients who underwent additional surgery, anus preservation was achieved on the basis of the pathological results from PAEM. CONCLUSIONS: PAEM for lesions with severe fibrosis exhibiting the muscle-retracting sign appears to be both safe and useful.

The impact of preoperative carbohydrate loading on intraoperative body temperature: a randomized controlled clinical trial.

BACKGROUND: Preoperative carbohydrate loading (CHO) is one element of the enhanced recovery after surgery protocol. No clinical trial has investigated the impact of preoperative CHO on intraoperative body temperature. METHODS: This study was a single-center, prospective, randomized controlled clinical trial involving patients undergoing laparoscopic colon cancer surgery. The primary end point was the intraoperative core temperature during surgery, which was measured at 30-min intervals for 150 min after starting surgery. The secondary end points were short-term outcomes and body composition changes. RESULTS: From July 2013 to May 2014, we randomized 70 patients into the control group (n = 33) or CHO group (n = 31); six patients were excluded. The core temperature of the CHO group 90, 120, and 150 min after starting surgery was significantly lower than that of the control group (control vs. CHO, respectively: 90 min; 36.26 ± 0.41 vs. 36.05 ± 0.43 °C, p = 0.0233, 120 min; 36.30 ± 0.44 vs. 36.06 ± 0.50 °C, p = 0.0283, 150 min; 36.33 ± 0.50 vs. 36.01 ± 0.56 °C, p = 0.0186). We also found a significant difference in body weight loss (control vs. CHO, respectively: - 1.6 ± 0.8 vs. - 0.9 ± 1.4 kg, p = 0.0304) and loss of lower limb muscle mass (- 0.7 ± 0.7 vs. - 0.3 ± 0.6 kg, p = 0.0110) between the control and CHO groups, respectively. CONCLUSION: CHO had no effect on raising the intraoperative core temperature, and no negative impact on the perioperative outcome. CHO prevented the loss of lower limb muscle mass, which may lead to better postoperative recovery.

Risk factors for anastomotic leakage after laparoscopic surgery with the double stapling technique for stage 0/I rectal carcinoma: a subgroup analysis of a multicenter, single-arm phase II trial.

PURPOSE: The aim of this study was to determine the risk factors for anastomotic leakage after laparoscopic rectal surgery. METHODS: We conducted a prospective trial involving 395 patients with stage 0/I rectal carcinoma who underwent laparoscopic low anterior resection using a double stapling technique. Data concerning variables related to patient background, tumors and surgical factors were evaluated. The outcomes with respect to anastomotic leakage were recorded, and univariate and multivariate analyses were performed to identify relevant risk factors. RESULTS: The overall anastomotic leakage rate was 8.4%. A univariate analysis showed male gender (P = 0.006) and preoperative blood sugar level (P = 0.0034) to be significantly associated with anastomotic leakage. The variables of gender, preoperative blood sugar level, American Society of Anesthesiologists (ASA) classification (P = 0.15), transanal decompression tube (P = 0.06) and number of stapler cartridges used for rectal transection (P = 0.18) were selected for the multivariate analysis because of their P values being <0.2. The multivariate analysis identified male gender (odds ratio 4.12, P = 0.006) and the absence of a transanal decompression tube (odds ratio 3.11, P = 0.0484) as independent risk factors predicting anastomotic leakage. CONCLUSIONS: Male gender and the absence of a transanal decompression tube appeared to be independent risk factors for anastomotic leakage. Insertion of a transanal decompression tube may help prevent anastomotic leakage after low anterior resection, particularly in male patients.

[MINIMALLY INVASIVE SURGERY FOR COLORECTAL CANCER BASED ON VIRTUAL SURGICAL ANATOMY].

For advanced right colon cancer, we perform lymph node dissection exposing the so-called surgical trunk. For the resection of advanced distal sigmoid/rectal cancer, we routinely perform lymph node dissection around the root of the inferior mesenteric artery, preserving the left colic artery. To perform either of these procedures safely, it is important to know the precise vascular anatomy with individual variations. However, there are major issues in laparoscopic surgery, such as a lack of tactile sensation and limited visual field. To overcome these issues and identify the vascular anatomy of each patient accurately, we have applied integrated three-dimensional computed tomography (3D-CT) imaging as a preoperative simulation and for intraoperative navigation since July 2000. Integrated 3D-CT imaging appears to be useful, especially for cancer located around the left flexure of the transverse colon, where major variations in vascular anatomy occur. Using the no-touch technique appropriately with the precise determination of laparoscopic surgical anatomy based on simulation and navigation by integrated 3D-CT imaging for each patient, systematic lymphadenectomy in addition to lateral lymph node dissection with tailor-made vascular laparoscopic dissection for the treatment of advanced lower rectal cancer appears to be feasible and a more meticulous approach compared with conventional open surgery.

Oncological impact of laparoscopic lymphadenectomy with preservation of the left colic artery for advanced sigmoid and rectosigmoid colon cancer.

BACKGROUND: Laparoscopic lymphadenectomy around the inferior mesenteric artery (IMA) with preservation of the left colic artery (LCA) remains a controversial approach. The aim of the study was to investigate the clinical outcomes. METHODS: This study analysed 211 patients who underwent laparoscopic resection of advanced (≥T3) sigmoid and rectosigmoid colon cancers with D3 lymphadenectomy including 91 high ligations of the IMA (HL) and 120 low ligations with preservation of the LCA (LL) from January 1998 to December 2009. RESULTS: There were no significant differences in operative result between the groups. In stage II cancer, the overall survival rate (94.8% HL vs. 91.8% LL; 95% confidence interval (CI), -0.8 to 0.68, p = 0.920) and disease-free survival (93.0% HL vs. 87.6% LL; 95% CI, -0.8 to 0.40, p = 0.540) did not differ significantly between the two groups. A similar tendency in overall survival was observed in patients with stage III cancer (88.3% HL vs. 86.9% LL; 95% CI, -0.44 to 0.57, p = 0.989) and disease-free survival (71.4% HL vs. 69.8% LL; 95% CI, -0.38 to 0.40, p = 0.637). CONCLUSIONS: Laparoscopic lymphadenectomy around the IMA with preservation of the LCA resulted in acceptable clinical outcomes in patients with advanced sigmoid and rectosigmoid colon cancer.

Prediction model of the risk for lateral local recurrence in locally advanced rectal cancer without enlarged lateral lymph nodes: Lessons from a Japanese multicenter pooled analysis of 812 patients.

Aim: Although the oncological impact of lateral lymph node dissection on enlarged lateral lymph nodes has been gradually accepted over the last decade, that on lateral lymph nodes without swelling remains doubtful. This study aimed to develop a prediction model for the future risk of lateral local recurrence and to clarify the value of adding lateral lymph node dissection in locally advanced rectal cancer without enlarged lateral lymph nodes. Methods: This retrospective, multi-institutional study recruited 812 patients with cStage II/III low rectal cancer without enlarged lateral lymph nodes <7 mm. Total lateral local recurrence was a hypothetical value of future risk of lateral local recurrence when lateral lymph node dissection was never performed. Results: Overall, total lateral local recurrences were observed in 67 patients (8.3%). In the multivariate analyses, the strongest risk factor for total local recurrences was no preoperative chemoradiotherapy (odds ratio [OR][95%Cl]: 33.2 [4.56-241.7], P < 0.001), followed by tumor distance ≤40 mm (OR [95%Cl]: 2.71 [1.51-4.86], P < 0.001) and lateral lymph node 5-7 mm (OR[95%Cl]: 2.38 [1.26-4.48], P = 0.007). In patients with lateral lymph nodes of 5-7 mm, the total lateral recurrence rate was 4.8% after preoperative chemoradiotherapy. Lateral lymph node dissection could reduce from a total lateral local recurrence of 21.6% to an actual lateral local recurrence of 8.0% in patients without preoperative treatment. Conclusion: We introduce a novel prediction model of future risk of lateral local recurrences, which has the potential to enable us to indicate lateral lymph node dissection selectively according to the patients' risks.

Laparoscopic surgery for stage 0/I rectal carcinoma: short-term outcomes of a single-arm phase II trial.

BACKGROUND AND OBJECTIVES: To examine the technical and oncological feasibility of laparoscopic surgery for rectal carcinoma, we conducted a single-arm phase II trial to evaluate laparoscopic surgery for stage 0/I rectal carcinoma, and short-term surgical outcomes were evaluated. METHODS: Accredited surgeons from 43 institutions in Japan participated in the study. Eligibility criteria included histologically proven rectal carcinoma; clinical stage 0/I; tumor size 8 cm or smaller; patient age 20 to 75 years; no bowel obstruction; and written informed consent. Patients were registered preoperatively. The planned sample size was 490. Surgical outcomes were evaluated. RESULTS: A total of 495 patients were registered between February 2008 and August 2010. Five patients were ineligible after registration. Conversion to open surgery was needed for 8 (1.6%) patients. Sphincter-preserving procedures were performed in 477 (97%) patients. Median operative time was 270 minutes, and median blood loss was 28 mL. Postoperative median intervals until liquid and solid intake were 1 and 3 days, respectively, and the median postoperative hospital stay was 12 days. The positive resection margin rate was 0.4% (2/490), and 68.6% (336/490) of the patients were graded stage 0/I. There were no perioperative mortalities. Twenty-four intraoperative and 160 postoperative complications occurred, and the morbidity rate was 23.9% (117/490). The anastomotic leakage rate in patients who underwent anterior resection was 8.3% (33/400), and that in patients who underwent intersphincteric resection was 9.1% (7/77). Nineteen (3.9%) patients underwent reoperation. CONCLUSIONS: Technically, laparoscopic surgery can be used for safe and radical resection of clinical stage 0/I rectal carcinoma. (ClinicalTrials.gov No. NCT00635466.).