Prevention of Petersen's hernia using jejunal mesentery fixing (Mefix).

BACKGROUND: The aim of this study was to compare the 1 year incidence of Petersen's hernia between individuals who were treated with the jejunal mesentery fixing (Mefix) method and those with the closure of Petersen's space method. MATERIAL AND METHODS: We retrospectively collected clinical data of patients who underwent gastrectomy for gastric cancers with the closure of Petersen's space defect (N = 49) and Mefix (N = 26). The Mefix method was performed by fixing the jejunal mesentery (jejunojejunostomy below 30 cm) to the transverse mesocolon using nonabsorbable barbed sutures. RESULTS: The procedure time for mesentery fixing (3.7 ± 1.1 mins) was significantly shorter than that for Petersen's space closure (7.5 ± 1.5 mins) (p < .001) although the operation times were similar between the two groups. There was no incidence of Petersen's hernias postoperatively in both groups. One case of reoperation was reported in the closure group due to small bowel obstruction by kinking of the jejunojejunostomy. CONCLUSION: We found no occurrence of Petersen's hernias postoperatively in either group. We also found that the Mefix method was faster and easier to perform than the closure method. The Mefix method is an excellent alternative method to prevent the occurrence of Petersen's hernia after B-II or Roux-en-Y reconstruction.

Minimally Invasive Versus Open Pancreatectomy for Right-Sided and Left-Sided G1/G2 Nonfunctioning Pancreatic Neuroendocrine Tumors: A Multicenter Matched Analysis with an Inverse Probability of Treatment-Weighting Method.

BACKGROUND: Limited evidence exists for the safety and oncologic efficacy of minimally invasive surgery (MIS) for nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) according to tumor location. This study aimed to compare the surgical outcomes of MIS and open surgery (OS) for right- or left-sided NF-PNETs. METHODS: The study collected data on patients who underwent surgical resection (pancreatoduodenectomy, distal/total/central pancreatectomy, duodenum-preserving pancreas head resection, or enucleation) of a localized NF-PNET between January 2000 and July 2017 at 14 institutions. The inverse probability of treatment-weighting method with propensity scores was used for analysis. RESULTS: The study enrolled 859 patients: 478 OS and 381 MIS patients. A matched analysis by tumor location showed no differences in resection margin, intraoperative blood loss, or complications between MIS and OS. However, MIS was associated with a longer operation time for right-sided tumors (393.3 vs 316.7 min; P < 0.001) and a shorter postoperative hospital stay for left-sided tumors (8.9 vs 12.9 days; P < 0.01). The MIS group was associated with significantly higher survival rates than the OS group for right- and left-sided tumors, but survival did not differ for the patients divided by tumor grade and location. Multivariable analysis showed that MIS did not affect survival for any tumor location. CONCLUSION: The short-term outcomes offered by MIS were comparable with those of OS except for a longer operation time for right-sided NF-PNETs. The oncologic outcomes were not compromised by MIS regardless of tumor location or grade. These findings suggest that MIS can be performed safely for selected patients with localized NF-PNETs.

Risk Factors for Recurrence in Pancreatic Neuroendocrine Tumor and Size as a Surrogate in Determining the Treatment Strategy: A Korean Nationwide Study.

INTRODUCTION: The prognostic factors of pancreatic neuroendocrine tumor (PNET) are unclear, and the treatment guidelines are insufficient. This study aimed to suggest a treatment algorithm for PNET based on risk factors for recurrence in a large cohort. METHODS: Data of 918 patients who underwent curative intent surgery for PNET were collected from 14 tertiary centers. Risk factors for recurrence and survival analyses were performed. RESULTS: The 5-year disease-free survival (DFS) rate was 86.5%. Risk factors for recurrence included margin status (R1, hazard ratio [HR] 2.438; R2, HR 3.721), 2010 WHO grade (G2, HR 3.864; G3, HR 7.352), and N category (N1, HR 2.273). A size of 2 cm was significant in the univariate analysis (HR 8.511) but not in the multivariate analysis (p = 0.407). Tumor size was not a risk factor for recurrence, but strongly reflected 2010 WHO grade and lymph node (LN) status. Tumors ≤2 cm had lower 2010 WHO grade, less LN metastasis (p < 0.001), and significantly longer 5-year DFS (77.9 vs. 98.2%, p < 0.001) than tumors >2 cm. The clinicopathologic features of tumors <1 and 1-2 cm were similar. However, the LN metastasis rate was 10.3% in 1-2-cm sized tumors and recurrence occurred in 3.0%. Tumors <1 cm in size did not have any LN metastasis or recurrence. DISCUSSION/CONCLUSION: Radical surgery is needed in suspected LN metastasis or G3 PNET or tumors >2 cm. Surveillance for <1-cm PNETs should be sufficient. Tumors sized 1-2 cm require limited surgery with LN resection, but should be converted to radical surgery in cases of doubtful margins or LN metastasis.

A comparison of postoperative outcomes after open and laparoscopic reduction of Petersen's Hernia: a multicenter observational cohort study.

BACKGROUND: The aim of this multicenter cohort study was to compare the clinical courses between open and laparoscopic Petersen's hernia (PH) reduction. METHOD: We retrospectively collected the clinical data of patients who underwent PH repair surgery after gastrectomy for gastric cancer from 2015-2018. Forty patients underwent PH reduction operations that were performed by six surgeons at four hospitals. Among the 40 patients, 15 underwent laparoscopic PH reduction (LPH), and 25 underwent open PH reduction (OPH), including 4 patients who underwent LPH but required conversion to OPH. RESULTS: We compared the clinical factors between the LPH and OPH groups. In the clinical course, we found no differences in operation times or intraoperative bowel injury, morbidity, or mortality rates between the two groups (p > 0.05). However, the number of days on a soft fluid diet (OPH vs. LPH; 5.8 vs. 3.7 days, p = 0.03) and length of hospital stay (12.6 vs. 8.2 days, p = 0.04) were significantly less in the LPH group than the OPH group. Regarding postoperative complications, the OPH group had a case of pneumonia and sepsis with multi-organ failure, which resulted in mortality. In the LPH group, one patient experienced recurrence and required reoperation for PH. CONCLUSION: Laparoscopic PH reduction was associated with a faster postoperative recovery period than open PH reduction, with a similar incidence of complications. The laparoscopic approach should be considered an appropriate strategy for PH reduction in selected cases.

Surgical Outcomes of Hepatocellular Carcinoma With Bile Duct Tumor Thrombus: A Korea-Japan Multicenter Study.

OBJECTIVE: To identify optimal surgical methods and the risk factors for long-term survival in patients with hepatocellular carcinoma accompanied by macroscopic bile duct tumor thrombus (BDTT). SUMMARY BACKGROUND DATA: Prognoses of patients with hepatocellular carcinoma accompanied by BDTT have been known to be poor. There have been significant controversies regarding optimal surgical approaches and risk factors because of the low incidence and small number of cases in previous reports. METHODS: Records of 257 patients from 32 centers in Korea and Japan (1992-2014) were analyzed for overall survival and recurrence rate using the Cox proportional hazard model. RESULTS: Curative surgery was performed in 244 (94.9%) patients with an operative mortality of 5.1%. Overall survival and recurrence rate at 5 years was 43.6% and 74.2%, respectively. TNM Stage (P < 0.001) and the presence of fibrosis/cirrhosis (P = 0.002) were independent predictors of long-term survival in the Cox proportional hazards regression model. Both performing liver resection equal to or greater than hemihepatectomy and combined bile duct resection significantly increased overall survival [hazard ratio, HR = 0.61 (0.38-0.99); P = 0.044 and HR = 0.51 (0.31-0.84); P = 0.008, respectively] and decreased recurrence rate [HR = 0.59 (0.38-0.91); P = 0.018 and HR = 0.61 (0.42-0.89); P = 0.009, respectively]. CONCLUSIONS: Clinical outcomes were mostly influenced by tumor stage and underlying liver function, and the impact of BDTT to survival seemed less prominent than vascular invasion. Therefore, an aggressive surgical approach, including major liver resection combined with bile duct resection, to increase the chance of R0 resection is strongly recommended.

Dynamic changes of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio predicts breast cancer prognosis.

BACKGROUND: We aimed to identify whether neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are more useful predictors after initial intention to treat than at the time of diagnosis. METHODS: We collected the medical data of 533 patients. The results of the peripheral blood sampling before the primary treatments were labeled as initial cohort, and those obtained between 24 and 36 months after initial treatment were defined as the 2nd cohort. Delayed metastasis has been defined as distant metastasis 2 years after treatment, and survival outcome was estimated and compared across groups. RESULTS: Median follow-up duration was 74 months (24-162 months), and 53 patients experienced delayed metastasis. In univariate analysis, metastasis-free survival, patient age at diagnosis, tumor size, axillary lymph node metastasis, HER-2 status, initial NLR and PLR, and 2nd NLR and PLR were found to be significantly associated with delayed metastasis. However, in multivariate analysis, only the 2nd NLR and PLR were found to be significantly associated with delayed metastasis, excluding initial NLR and PLR. Metastasis-free survival was analyzed through the pattern changes of NLR or PLR. The results revealed that patients with continued low NLR and PLR values at pre- and post-treatment (low initial values and 2nd values) showed a significantly better prognosis than those with a change in value or continued high NLR and PLR. CONCLUSIONS: We identified that patients with persistent high NLR and PLR after initial treatment have significant worse prognosis in terms of late metastasis. Therefore, these results suggest that NLR and PLR are more useful in predicting prognosis post-treatment.

Safety and efficacy of post-anastomotic intraoperative endoscopy to avoid early anastomotic complications during gastrectomy for gastric cancer.

BACKGROUND: Anastomotic complications such as leaks, bleeding, and stricture remain the most serious complications of surgery for gastric cancer. No perfect method exists for an accurate and reliable prevention of these complications. This study investigated the safety and efficacy of post-anastomotic intraoperative endoscopy (PAIOE) for avoidance of early anastomotic complications during gastrectomy in gastric cancer. METHODS: This retrospective case-control study enrolled patients from a tertiary care, academic medical center. Routine PAIOE was performed on 319 patients undergoing gastrectomy for gastric cancer between 2015 and 2016. As controls, without PAIOE 270 patients from 2013 to 2014 were used for comparison. Early anastomotic complications and outcomes after PAIOE were determined. RESULTS: Although there were no differences between the PAIOE and non-PAIOE group in terms of overall complication rates (20.1% vs 26.7%; P > 0.05), there were fewer complications related to anastomosis (3.4% vs 8.9%; P < 0.01) in the PAIOE group. The PAIOE group had rates of 2.5% for anastomotic leakage, 0.9% for intra-luminal bleeding, and 0% for anastomotic stenosis, while the non-PAIOE group exhibited rates of 5.6%, 2.6%, and 0.7%, respectively. Thirty-one abnormalities were detected in 26 PAIOE patients (9.71%) (20 venous bleeding, 7 mucosal tearing, 2 air leaks, 1 arterial bleeding, and 1 anastomotic stricture). All abnormalities were corrected by proper interventions (13 reinforced additional suture, 13 endoscopic hemostasis, and 2 re-anastomosis). There were no morbidities associated with PAIOE. CONCLUSIONS: PAIOE appears to be a safe and reliable procedure to evaluate the stability of gastrointestinal anastomosis for gastric cancer patients. Further data collection and a well-designed prospective study are needed to confirm the validity of PAIOE.

Safety and location analysis of transumbilical endoscopic submucosal dissection with single-basin lymph node dissection in the upper gastric body: a porcine model.

BACKGROUND: In our previous study, transumbilical endoscopic submucosal dissection (TU-ESD) was revealed to be feasible, but delayed gastric perforation was observed in 30% of ESD sites. In this study, we aimed to verify locations at which it is feasible to perform TU-ESD in the upper gastric body and to demonstrate the safety of TU-ESD in single-basin lymph node dissection (SBLND). METHODS: In vitro, TU-ESD was performed at three lesion sites (anterior wall, AW; posterior wall, PW; and lesser curvature, LC) in each porcine stomach using an EASIE-R tray (cases = 10). In vivo, TU-ESD was performed with SBLND in 9 pigs. Seven days after the operation, the pigs were sacrificed and examined. RESULTS: In the in vitro feasibility study, the TU-ESD time was significantly faster in the PW group (5.9 ± 2.0 min) than in the LC group (8.5 ± 1.5 min) (p < 0.05) in all 10 cases. In the in vivo survival study, TU-ESD with SBLND was successfully performed without any complications (N = 9). There were no cases of delayed perforation, and healing ulcers were found in all pigs 7 days after the operation. Ulcer size (5.2 ± 3.5 cm2) was approximately 36% smaller than that observed at the ESD operation site (8.1 ± 1.9 cm2) (p = 0.05). Epithelialization in the margin and healing of the gastric ulcers were confirmed by microscopy. CONCLUSIONS: TU-ESD with SBLND is a feasible and safe method. The upper posterior gastric body could be the most feasible location for performing TU-ESD, perhaps because of the difference in the subcutaneous dissection time.

Clinicopathologic analysis of intraductal papillary neoplasm of bile duct: Korean multicenter cohort study.

BACKGROUND: IPNB is very rare disease and most previous studies on IPNB were case series with a small number due to low incidence. The aim of this study is to validate previously known clinicopathologic features of intraductal papillary neoplasm of bile duct (IPNB) based on the first largest multicenter cohort. METHODS: Among 587 patients previously diagnosed with IPNB and similar diseases from each center in Korea, 387 were included in this study after central pathologic review. We also reviewed all preoperative image data. RESULTS: Of 387 patients, 176 (45.5%) had invasive carcinoma and 21 (6.0%) lymph node metastasis. The 5-year overall survival was 80.9% for all patients, 88.8% for IPNB with mucosal dysplasia, and 70.5% for IPNB with invasive carcinoma. According to the "Jang & Kim's modified anatomical classification," 265 (68.5%) were intrahepatic, 103 (26.6%) extrahepatic, and 16 (4.1%) diffuse type. Multivariate analysis revealed that tumor invasiveness was a unique predictor for survival analysis. (p = 0.047 [hazard ratio = 2.116, 95% confidence interval 1.010-4.433]). CONCLUSIONS: This is the first Korean multicenter study on IPNB through central pathologic and radiologic review process. Although IPNB showed good long-term prognosis, relatively aggressive features were also found in invasive carcinoma and extrahepatic/diffuse type.

Validation of the prognostic performance in various nodal staging systems for gallbladder cancer: results of a multicenter study.

BACKGROUND: Although the current nodal staging system for gallbladder cancer (GBC) was changed based on the number of positive lymph nodes (PLN), it needs to be evaluated in various situations. METHODS: We reviewed the clinical data for 398 patients with resected GBC and compared nodal staging systems based on the number of PLNs, the positive/retrieved LN ratio (LNR), and the log odds of positive LN (LODDS). Prognostic performance was evaluated using the C-index. RESULTS: Subgroups were formed on the basis of an restricted cubic spline plot as follows: PLN 3 (PLN = 0, 1-2, ≥ 3); PLN 4 (PLN = 0, 1-3, ≥ 4); LNR (LNR = 0, 0-0.269, ≥ 0.27); and LODDS (LODDS < - 0.8, - 0.8-0, ≥ 0). The oncological outcome differed significantly between subgroups in each system. In all patients with GBC, PLN 4 (C-index 0.730) and PLN 3 (C-index 0.734) were the best prognostic discriminators of survival and recurrence, respectively. However, for retrieved LN (RLN) ≥ 6, LODDS was the best discriminator for survival (C-index 0.852). CONCLUSION: The nodal staging system based on PLN was the optimal prognostic discriminator in patients with RLN < 6, whereas the LODDS system is adequate for RLN ≥ 6. The following nodal staging system considers applying different systems according to the RLN.

Validation of the oncologic effect of hepatic resection for T2 gallbladder cancer: a retrospective study.

BACKGROUND: While extended cholecystectomy is recommended for T2 gallbladder cancer (GBC), the role of hepatic resection for T2 GBC is unclear. This study aimed to identify the necessity of hepatic resection in patients with T2 GBC. METHODS: Data of 81 patients with histopathologically proven T2 GBC who underwent surgical resection between January 1999 and December 2017 were enrolled from a retrospective database. Of these, 36 patients had peritoneal-side (T2a) tumors and 45 had hepatic-side (T2b) tumors. To identify the optimal surgical management method, T2 GBC patients were classified into the hepatic resection group (n = 44, T2a/T2b = 20/24) and non-hepatic resection group (n = 37, T2a/T2b = 16/21). The recurrence pattern and role of hepatic resection for T2 GBC were then investigated. RESULTS: Mean age of the patients was 69 (range 36-88) years, and the male-to-female ratio was 42:39 (male, 51.9%; female, 48.1%). Hepatic-side GBC had a higher rate of recurrence than peritoneal-side GBC (44.4% vs. 8.3%, p = 0.006). The most common type of recurrence in T2a GBC was para-aortic lymph node recurrence (n = 2, 5.6%); the most common types of recurrence in T2b GBC were para-aortic lymph node recurrence (n = 7, 15.6%) and intrahepatic metastasis (n = 6, 13.3%). Hepatic-side GBC patients had worse survival outcomes than peritoneal-side GBC patients (76.0% vs. 96.6%, p = 0.041). Hepatic resection had no significant treatment effect in T2 GBC patients (p = 0.272). Multivariate analysis showed that lymph node metastasis was the only significant prognostic factor (p = 0.002). CONCLUSIONS: Hepatic resection is not essential for curative treatment in T2 GBC, and more systemic treatments are needed for GBC patients, particularly for those with T2b GBC.

Stereotactic body radiation therapy using a respiratory-gated volumetric-modulated arc therapy technique for small hepatocellular carcinoma.

BACKGROUND: Volumetric-modulated arc therapy (VMAT) is a highly sophisticated linear accelerator-based treatment method, and allows dose rate-changing intensity modulation with gantry rotation. We report our clinical experiences with stereotactic body radiation therapy (SBRT) using a respiratory-gated VMAT technique for patients with hepatocellular carcinoma (HCC) when established curative treatments cannot be applied. METHODS: A total of 119 patients (139 lesions) with HCC who were treated with SBRT were registered between March 2012 and July 2013 at our institution. A dose of 10-15 Gy per fraction was applied over 3-4 consecutive days, resulting in a total dose of 30-60 Gy. RESULTS: The median follow-up period was 25.8 months (range, 3.2-36.8 months). The overall 3-year survival rate was 83.8%. The local control rate at 3 years was 97.0% in all treated lesions. Multivariate analysis revealed that the Child-Pugh class before SBRT had significant effects on overall survival (Child-Pugh A: hazard ratio = 0.463; 95% CI, 0.262-0.817; p = 0.008). CONCLUSIONS: SBRT using a respiratory-gated VMAT technique was an excellent ablative treatment modality for patients with HCC. SBRT is a good alternative treatment for patients with small HCCs that are unsuitable for surgical resection or local ablative therapy.

Feasibility of a novel laparoscopic technique with unidirectional knotless barbed sutures for the primary closure of duodenal ulcer perforation.

BACKGROUND: Laparoscopic primary repair is one of the main procedures used for perforated gastric ulcers, and this technique requires reproducible and secure suturing. The aim of this study was to investigate the safety and efficacy of a novel continuous suture method with barbed sutures during laparoscopic repair for perforated peptic ulcers. PATIENTS AND METHODS: Clinical data from 116 consecutive patients undergoing laparoscopic repair for perforated peptic ulcers were collected between November 2009 and October 2015. Continuous suturing with 15-cm-long unidirectional absorbable barbed sutures was used for laparoscopic repair in the study group, termed group V (n = 51). Patients who underwent laparoscopic repair with conventional interrupted sutures were defined as group C (n = 65). The complication and operative data were compared between groups. RESULTS: Although there was no difference between group V and group C in the overall complication rate (15.7% vs. 24.6%; p = 0.259), the complication rate related to suturing was lower (3.9% vs. 15.4%; p = 0.04) in group V. Group V showed rates of 0% for leakage, 2% for intra-abdominal fluid collection, and 2% for stricture; the corresponding rates in group C were 3.1, 7.7, and 4.6%, respectively. Regarding operative data, the total operation time (V vs. C, 87.7 min vs. 131.2 min), total suture time (7.1 min vs. 25.3 min), and suture time per stitch (1.2 min vs. 6.2 min) were significantly shorter in group V than in group C (p < 0.001). CONCLUSION: The use of a continuous suture technique with unidirectional barbed sutures is as safe as the conventional suture technique and allows easier and faster suturing in the repair of perforated peptic ulcers.

Magnetic resonance image-guided brachytherapy for cervical cancer : Prognostic factors for survival.

OBJECTIVE: The purpose of this work was to identify prognostic factors for survival after magnetic resonance image (MRI)-guided brachytherapy combined with external beam radiotherapy for cervical cancer. MATERIAL AND METHODS: External beam radiotherapy of 45-50.4 Gy was delivered by either three-dimensional conformal radiotherapy or helical tomotherapy. Patients also received high-dose-rate MRI-guided brachytherapy of 5 Gy in 6 fractions. RESULTS: We analyzed 128 patients with International Federation of Gynecology and Obstetrics stage IB-IVB cervical cancer who underwent MRI-guided brachytherapy. Most patients (96 %) received concurrent chemotherapy. Pelvic lymph node metastases and para-aortic lymphadenopathies were found in 62 % and 14 % of patients, respectively. The median follow-up time was 44 months. Complete remission was achieved in 119 of 128 patients (93 %). The 5­year local recurrence-free, cancer-specific, and overall survival rates were 94, 89, and 85 %, respectively. Negative pelvic lymphadenopathy, gross tumor volume (GTV) dose covering 90 % of the target (GTV D90) of >110 Gy, and treatment duration ≤56 days were associated with better overall survival in univariate analyses. Multivariable analysis showed that GTV D90 of >110 Gy and treatment duration ≤56 days were possibly associated with overall survival with near-significant P-values of 0.062 and 0.073, respectively. CONCLUSIONS: The outcome of MRI-guided brachytherapy combined with external beam radiotherapy in patients with cervical cancer was excellent. GTV D90 of >110 Gy and treatment duration ≤56 days were potentially associated with overall survival.

Comparison of perioperative and oncologic outcomes between open and laparoscopic liver resection for intrahepatic cholangiocarcinoma.

BACKGROUND: Laparoscopic liver resection (LLR) has become an essential method for treating malignant liver tumors. Although the perioperative and oncologic outcomes of LLR in patients with hepatocellular carcinoma have been reported, there are few reports of LLR for intrahepatic cholangiocarcinoma (IHCC). METHODS: Patients who underwent liver resection for T1 or T2 IHCC between March 2010 and March 2015 in Gyeongsang National University Hospital were enrolled. They were divided into open (n = 23) and laparoscopic (n = 14) approaches, and the perioperative and oncologic outcomes were compared. RESULTS: The Pringle maneuver was less frequently used (p = 0.015) and estimated blood loss was lesser (p = 0.006) in the laparoscopic group. There were no significant differences in complication rate (p = 1.000), hospital stay (p = 0.371), tumor size (p = 0.159), lymph node metastasis (p = 0.127), and the number of retrieved lymph nodes (p = 0.553). The patients were followed up for a median of 21 months. The 3-year overall survival (OS) and recurrence-free survival (RFS) rates were 74.7 and 55.2 %, respectively. No differences were observed in the 3-year OS (75.7 vs 84.6 %, p = 0.672) and RFS (56.7 vs 76.9 %, p = 0.456) rates between the open and laparoscopic groups, even after the groups were divided into patients that received liver resection with or without lymph node dissection. CONCLUSION: LLR for IHCC is a treatment modality that should be considered as an option alongside open liver resection in selected patients.

A new method and device of aligning patient setup lasers in radiation therapy.

The aim of this study is to develop a new method to align the patient setup lasers in a radiation therapy treatment room and examine its validity and efficiency. The new laser alignment method is realized by a device composed of both a metallic base plate and a few acrylic transparent plates. Except one, every plate has either a crosshair line (CHL) or a single vertical line that is used for alignment. Two holders for radiochromic film insertion are prepared in the device to find a radiation isocenter. The right laser positions can be found optically by matching the shadows of all the CHLs in the gantry head and the device. The reproducibility, accuracy, and efficiency of laser alignment and the dependency on the position error of the light source were evaluated by comparing the means and the standard deviations of the measured laser positions. After the optical alignment of the lasers, the radiation isocenter was found by the gantry and collimator star shots, and then the lasers were translated parallel to the isocenter. In the laser position reproducibility test, the mean and standard deviation on the wall of treatment room were 32.3 ± 0.93 mm for the new method whereas they were 33.4 ± 1.49 mm for the conventional method. The mean alignment accuracy was 1.4 mm for the new method, and 2.1 mm for the conventional method on the walls. In the test of the dependency on the light source position error, the mean laser position was shifted just by a similar amount of the shift of the light source in the new method, but it was greatly magnified in the conventional method. In this study, a new laser alignment method was devised and evaluated successfully. The new method provided more accurate, more reproducible, and faster alignment of the lasers than the conventional method.

Decreased expression of heat shock protein 20 in colorectal cancer and its implication in tumorigenesis.

Heat shock protein 20 (HSP20), which is a member of the small heat shock protein family, is known to participate in many pathological processes, such as asthma, intimal hyperplasia, and insulin resistance. However, the function of HSP20 in cancer development is not yet fully understood. In this study, we identified HSP20 as a down-regulated protein in 20 resected colorectal cancer (CRC) specimens compared with their paired normal tissues. Because HSP20 proteins were barely detectable in HCT-116 cells (a human colorectal cancer cell line), recombinant adenovirus encoding HSP20 (Ad-HSP20) was used to induce HSP20 overexpression in HCT-116 cells. Infection of Ad-HSP20, but not control adenovirus (Ad-GFP), reduced viability, and induced massive apoptosis in a time-dependent manner. The forced expression of HSP20 enhanced caspase-3/7 activity and down-regulated the anti-apoptotic Bcl-xL and Bcl-2 mRNA and protein levels. In addition, immunohistochemical analysis of 94 CRC specimens for HSP20 protein showed that reduced HSP20 expression was related to advanced TNM stage, lymph node metastasis, and tumor recurrence. Our study shows, for the first time, that expression of the HSP20 protein has a pro-death role in colorectal cancer cells. Therefore, HSP20 may have value as a prognostic tumor marker and its overexpression might be a novel strategy for CRC therapy.

Prognostic importance of ultrasound BI-RADS classification in breast cancer patients.

OBJECTIVE: We investigated the prognostic importance of pre-operative Breast Imaging Reporting and Data System classification in ultrasound imaging. METHODS: Histopathological differences and disease-free survival were analyzed in Breast Imaging Reporting and Data System classification subgroups. Univariate and multivariate analyses were used to identify the prognostic factors. RESULTS: We identified 531 invasive breast cancer patients eligible for this study. Most patients classified as Breast Imaging Reporting and Data System 5 had large tumors and a higher rate of lymph node metastasis. However, hormonal receptor or HER-2 status did not differ according to Breast Imaging Reporting and Data System classification. During a median post-operative follow-up of 42.0 months, 43 patients were diagnosed with a disease-specific event. Disease-free survival was significantly lower in patients with Breast Imaging Reporting and Data System 5 than in patients with Breast Imaging Reporting and Data System 3-4. Subgroup analysis of patients with invasive breast cancer of Stage I showed that Breast Imaging Reporting and Data System 5 was an independent negative prognostic indicator of disease-free survival (hazard ratio 9.195; 95% confidence interval, 1.175-71.955; P = 0.035). CONCLUSIONS: Breast Imaging Reporting and Data System classification might be considered as prognostic factors especially in Stage I breast cancer. Further confirmatory studies are needed.

A noble method for intraoperative fine localization during laparoscopic gastric local resection: endoscopic submucosal cutting and light transmission.

BACKGROUND: The main requirements when performing laparoscopic local resection for early mucosal tumors of the stomach are a clearly defined cancer-free margin and precise tumor localization. In this study, a novel method for precise intraoperative tumor localization and appropriate resection in a porcine model is introduced: endoscopic submucosal cutting and light transmission (ESCLT). METHODS: A total of 15 cases of laparoscopic local resection were performed in 6 pigs. The size of the target lesions was approximately 20 mm. The imaginary lesions were located in the high body anterior wall, posterior wall, lower body posterior wall, angle, and antrum anterior wall of the stomach. Mucosal marking around the lesions, mucosal precutting surrounding the marking, and submucosal cutting along the precutting line using white light endoscopy were sequentially performed. Next, an endoscopic light source was placed directly in front of the lesion. Exact oval-shaped submucosal cutting margins were identified via laparoscopy. Laparoscopic local resection was performed after the minimal distance from the stapler line to the submucosal cutting line was confirmed. The sizes of the mucosal marking, submucosal cutting line, and the entire resected mucosa and serosa were measured. RESULTS: The procedure was completed successfully in all pigs. Local resection was completed on all of the lesions. The mean endoscopic and laparoscopic procedure times were 26.1 and 12.7 min, respectively. The mean size of the resected specimens was: (i) marking lesion, 22 × 19.5 mm; (ii) submucosal cutting line, 26.7 × 23.2 mm; (iii) entire resected mucosa, 37 × 31 mm; and (iv) entire resected serosa, 41.7 × 33.1 mm. There was no intraoperative morbidity. CONCLUSION: ESCLT provides a precise and useful method of intraoperative tumor localization during laparoscopic local resection of the stomach in terms of minimizing the resection of normal stomach tissue and guaranteeing adequate mucosal safety margins.