Saccadic eye movement speed is related to variations in phantom array effect visibility.

The phantom array effect is one of the temporal light artefacts that can decrease performance and increase fatigue. The phantom array effect visibility shows large individual differences; however, the dominant factors that can explain these individual differences remain unclear. We investigated the relationship between saccadic eye movement speed and phantom array visibility at two different angles and four different directions of saccadic eye movement. The peak speed of saccadic eye movement and the phantom array effect visibility were measured at different modulation frequencies of the light source. Our results show that phantom array visibility increased as eye movement speed increased; the phantom array visibility was higher at a wide viewing angle with fast eye movement speed than at a narrow viewing angle. Moreover, when clustered into subgroups according to individual eye movement speed, the mean speed of the saccadic eye movement of each subgroup is related to the variations in the visibility of the phantom array effect of the subgroup. Therefore, saccadic eye movement speed is related to variations in phantom array effect visibility.

Pathological-Gait Recognition Using Spatiotemporal Graph Convolutional Networks and Attention Model.

Walking is an exercise that uses muscles and joints of the human body and is essential for understanding body condition. Analyzing body movements through gait has been studied and applied in human identification, sports science, and medicine. This study investigated a spatiotemporal graph convolutional network model (ST-GCN), using attention techniques applied to pathological-gait classification from the collected skeletal information. The focus of this study was twofold. The first objective was extracting spatiotemporal features from skeletal information presented by joint connections and applying these features to graph convolutional neural networks. The second objective was developing an attention mechanism for spatiotemporal graph convolutional neural networks, to focus on important joints in the current gait. This model establishes a pathological-gait-classification system for diagnosing sarcopenia. Experiments on three datasets, namely NTU RGB+D, pathological gait of GIST, and multimodal-gait symmetry (MMGS), validate that the proposed model outperforms existing models in gait classification.

Is Laparoscopic Complete Mesocolic Excision and Central Vascular Ligation Really Necessary for All Patients With Right-Sided Colon Cancer?

Colon cancer treatment is on the way to evolution over several decades. The minimally invasive surgery has improved postoperative short-term outcomes. Adjuvant chemotherapy has prolonged the survival of advanced colon cancer patients. Hohenberger proposed the noble concept of complete mesocolic excision (CME) which consists of 3 components: plane surgery, sufficient longitudinal bowel resection, and central vascular ligation (CVL). Mesocolic plane surgery shares the same surgical principle of total mesorectal excision, which is maintaining the intact mesothelial envelope. However, there remain debates about the extent of bowel resection and the level of CVL for maximizing lymph node dissection. There is no solid clinical evidence for the oncological necessity and benefit of extended radical dissection in right hemicolectomy. CME with CVL based on open surgery has been adopted in laparoscopic surgery. So, it is also necessary to look at how the CME could be transformed and successfully implanted in the laparoscopic era. Recent rapid advances in surgical technology and cancer biology are preparing for fundamental changes in cancer surgery. In this study, we reviewed the history, oncological necessity, and compatibility of CME for the right hemicolectomy in the laparoscopic era and outline the new perspectives on the evolution of cancer surgery.

The Safety and Feasibility of Laparoscopic Surgery for Very Low Rectal Cancer: A Retrospective Analysis Based on a Single Center's Experience.

In this work we intend to validate the long-term oncologic outcomes for very low rectal cancer over the past 20 years and to determine whether laparoscopic procedures are useful options for very low rectal cancer. A total of 327 patients, who electively underwent laparoscopic rectal cancer surgery for a lesion within 5 cm from the anal verge, were enrolled in this study and their long-term outcomes were reviewed retrospectively. Of 327 patients, 70 patients underwent laparoscopic low anterior resection (LAR), 164 underwent laparoscopic abdominal transanal proctosigmoidocolectomy with coloanal anastomosis (LATA), and 93 underwent laparoscopic abdominoperineal resection (APR). The conversion rate was 1.22% (4/327). The overall postoperative morbidity rate was 26.30% (86/327). The 5-year disease free survival (DFS), 5-year overall survival (OS), and 3-year local recurrence (LR) were 64.3%, 79.7%, and 9.2%, respectively. The CRM involvement was a significant independent factor for DFS (p = 0.018) and OS (p = 0.042) in multivariate analysis. Laparoscopic APR showed poorer 5-year DFS (47.8%), 5-year OS (64.0%), and 3-year LR (17.6%) than laparoscopic LAR (74.1%, 86.4%, 1.9%) and laparoscopic LATA (69.2%, 83.6%, 9.2%). Laparoscopic procedures for very low rectal cancer including LAR, LATA, and APR could be good surgical options in selective patients with very low rectal cancer.

Reconsideration of the Safety of Laparoscopic Rectal Surgery for Cancer.

The oncological outcomes of laparoscopic rectal cancer surgery were evaluated in recent multicenter randomized clinical trials (RCTs). The MRC-CLASSIC, COLOR II, and COREAN trials found no differences in local recurrence or diseasefree survival rate between laparoscopic and open surgery. However, the noninferiority of laparoscopic surgery with respect to open surgery for rectal cancer was not established on statistical analysis in the ACOSOG Z6051 and the ALaCaRT trials. Quality of total mesorectal excision (TME) is one of the most important prognostic factors. Incomplete TME had unfavorable oncologic outcomes compared to complete TME. Although TME quality can be clearly identified on pathologic evaluation, there is controversy regarding the acceptable range of oncologically safe TME for laparoscopic surgery. It is not certain whether near-complete TME has an unfavorable oncologic impact and whether laparoscopic surgery with near-complete TME is an oncological threat. Therefore, the surgical community will be interested in the long-term outcomes and meta-analyses of ongoing large-scale RCTs. Laparoscopic rectal cancer surgery has been steadily improving its safety for oncology surgery, which has been reported consistently in various multicenter RCTs. To improve surgical quality, colorectal surgeons should choose the most appropriate surgical technique, including laparoscopic surgery.

Comparison of the effects of an ERAS program and a single-port laparoscopic surgery on postoperative outcomes of colon cancer patients.

Advancement of the surgical modality and perioperative care are the two main dimensions for the modern improvement of surgical outcome. The purpose of this study was to compare the effectiveness of the two by using the data from the single-port laparoscopic surgery and the early recovery after surgery (ERAS) program. Patients who underwent elective surgery for primary adenocarcinoma of the colon were divided into three groups and compared: ERAS (multi-port laparoscopic surgery with ERAS perioperative care), Conventional-SILS (single-port surgery with conventional perioperative care), or Conventional-Multi (multi-port laparoscopic surgery with conventional perioperative care). Ninety-one, 83, and 96 patients were registered, respectively. There were no differences among the three groups in baseline characteristics except pathological stage and operation site in colon. Although the ERAS group started a soft diet earlier and had earlier discharge, there were no differences in intra- and post-operative morbidity rate, readmission rate, or reoperation rate. The ERAS perioperative care was a significant factor for reducing length of hospital stay in the multivariate analysis, while single-port surgery was not. In modern laparoscopic colon cancer treatment, a systemic approach such as the ERAS program appears to be more effective than a technical approach for significantly improving short-term surgical outcomes.

Oncologic Outcome and Morbidity in the Elderly Rectal Cancer Patients After Preoperative Chemoradiotherapy and Total Mesorectal Excision: A Multi-institutional and Case-matched Control Study.

OBJECTIVE: To determine the toxicity and oncologic outcome of neoadjuvant chemoradiotherapy (CRT) followed by curative total mesorectal excision (TME) in the elderly (≥70 yrs) and younger (<70 yrs) rectal cancer patients. BACKGROUND: Sufficient data for elderly rectal cancer patients who received definitive trimodality have not been accumulated yet. PATIENTS AND METHODS: A total of 1232 rectal cancer patients who received neoadjuvant CRT and TME were enrolled in this study. After propensity-score matching, 310 younger patients and 310 elderly patients were matched with 1:1 manner. Treatment response, toxicity, surgical outcome, recurrence, and survival were assessed and compared between the 2 groups of patients. RESULTS: The median age was 58 years for the younger patient group and 74 years for the elderly group. Pathologic complete response rates were not significantly different between the 2 groups (younger and elderly: 17.1% vs 14.8%, P = 0.443). The 5-year recurrence-free survival (younger and elderly: 67.7% vs 65.5%, P = 0.483) and overall survival (younger and elderly: 82.9% vs. 79.5%, P = 0.271) rates were not significantly different between the 2 groups either. Adjuvant chemotherapy after surgery was less frequently delivered to the elderly than that to younger patients (83.9% vs 69.0%). Grade 3 or higher acute hematologic toxicity was observed more frequently in the elderly than that in the younger group (9.0% vs 16.1%, P = 0.008). Late complication rate was higher in the elderly group compared with that in the younger group without statistical significance (2.6% vs 4.5%, P = 0.193). CONCLUSIONS: Although acute hematologic toxicity was observed more frequently in the elderly patients than that in the younger patients, elderly rectal cancer patients with good performance status who received preoperative CRT and TME showed favorable tumor response and recurrence-free survival similar to younger patients.

Clinical Significance of Discordance between Carcinoembryonic Antigen Levels and RECIST in Metastatic Colorectal Cancer.

PURPOSE: The purpose of this study was to investigate the prognostic implications of carcinoembryonic antigen (CEA) levels that are inconsistent with Response Evaluation Criteria in Solid Tumor (RECIST) responses in metastatic colorectal cancer patients. MATERIALS AND METHODS: We retrospectively evaluated 360 patients with at least one measurable lesion who received first-line palliative chemotherapy. CEA-response was defined as CEA-complete response (CR; CEA normalization), CEA-partial response (PR; ≥ 50% decrease in CEA levels), CEA-progressive disease (PD; ≥ 50% increase in CEA levels), and CEA-stable disease (SD; non-CR/PR/PD). Overall survival (OS) and progression-free survival (PFS) were evaluated according to CEA-response. RESULTS: In RECIST-PR patients, poorer CEA-response was associated with disease progression at the subsequent evaluation. In RECIST-SD patients, CEA-CR and -PR were associated with lower disease progression rates than CEA-PD at the subsequent evaluation. Correlations between survival outcome and CEA-response in same-category RECIST patients were assessed. In RECIST-PR patients, discordant CEA-response (CEA-PD/SD) was associated with poorer survival than CEA-CR/PR (median OS and PFS, 44.0 and 15.4 [CEA-CR], 28.9 and 12.5 [CEA-PR], 21.0 and 9.8 [CEA-SD], and 13.0 and 7.0 [CEA-PD] months, respectively; all p < 0.001). In RECIST-SD patients, favorable CEA-response produced better survival (median OS and PFS, 26.8 and 21.0 [CEA-CR], 21.0 and 11.0 [CEA-PR], 16.1 and 8.2 [CEA-SD], and 12.2 and 6.0 [CEA-PD] months, respectively; all p < 0.001). RECIST-PD patients with CEA-CR showed longer OS than those with CEA-PD. Multivariate analysis demonstrated that discordant CEA-response is a powerful prognostic factor for RECIST-PR and RECIST-SD patients. CONCLUSION: Among patients of the same RECIST-response categories, CEA-response patterns are significantly prognostic and strongly predictive of subsequent evaluation outcomes.

Multicenter, randomized single-port versus multiport laparoscopic surgery (SIMPLE) trial in colon cancer: an interim analysis.

BACKGROUND: Single-port laparoscopic surgery (SPLS) was recently introduced as an innovative minimally invasive surgery method. Retrospective studies have revealed the safety and feasibility of SPLS for colon cancer treatment. However, no prospective randomized trials have been performed. The multicenter, randomized SIMPLE (single-port versus multiport laparoscopic surgery) trial aimed to investigate short-term perioperative outcomes of SPLS for colon cancer treatment, compared with multiport laparoscopic surgery (MPLS). METHODS: Between August 2011 and April 2014, a total of 194 patients with colon cancer were recruited from seven hospitals in Korea. Patients were randomly allocated into the SPLS group (n = 99) or MPLS group (n = 95). The primary endpoint was postoperative complications. Operative, postoperative, and pathologic outcomes were analyzed after 50% of the patient study population had been recruited. RESULTS: The patients' demographic characteristics, operative times, estimated blood volume losses, numbers of harvested lymph nodes, and lengths of both resection margins were not significantly different between groups. In the SPLS group, the rates of conversion to MPLS and open surgery were 12.9 and 2.2%, respectively. Postoperative complications occurred in 10.8% of the SPLS, and 12.5% of the MPLS patients (p = 0.714). Times to functional recovery, pain scores, and amounts of analgesia were similar between groups. CONCLUSION: The results of this interim analysis suggested that SPLS is technically safe and appropriate when used for radical resection of colon cancer. (ClinicalTrials.gov Identifier: NCT01480128).

Laparoscopic Abdominal Transanal Proctocolectomy with Coloanal Anastomosis Is a Good Surgical Option in Selective Patients with Low-Lying Rectal Cancer: A Retrospective Analysis Based on a Single Surgeon's Experience.

PURPOSE: We intended to identify the oncological outcome for rectal cancer over the past 20 years and whether or not sphincter-preserving surgery is an appropriate approach for low-lying rectal cancer. MATERIALS AND METHODS: The oncological outcomes from a total of 418 patients who electively underwent rectal cancer surgery for a lesion located within 8 cm of the anal verge by a single colorectal surgeon were reviewed retrospectively. RESULTS: Of 418 patients, 175 patients underwent low anterior resection (LAR), 172 laparoscopic abdominal transanal proctocolectomy with coloanal anastomosis (LATA), and 71 abdominoperineal resection (APR). The factors related to the disease-free survival (DFS) were neoadjuvant chemoradiation (P = .016), pathologic stage (P < .001), circumferential margin involvement (P < .001), and initial (P = .016) and postoperative serum carcinoembryonic antigen level (P < .001). The factors related to the overall survival (OS) were similar with those related to DFS. Compared with DFS, OS, and local recurrence among three surgical techniques, APR was significantly poorer in DFS (P < .001), OS (P < .001), and local recurrence (P = .001), than was LAR or LATA. DISCUSSION: The LATA procedure is a technically feasible and oncologically safe surgical option for low-lying rectal cancer. We suggest that LATA may be a good surgical option in selective low-lying rectal cancer patients.

Procedural difficulty differences according to tumor location do not compromise the clinical outcome of laparoscopic complete mesocolic excision for colon cancer: a retrospective analysis.

Laparoscopic colectomy procedures and their corresponding difficulty levels may vary depending on the tumor location within the colon, and a laparoscopic complete mesocolic excision (CME) with central vascular ligation (CVL) would require more proficiency than a conventional laparoscopic colectomy. We aimed to report our laparoscopic CME with CVL data and to investigate the clinical outcome differences of laparoscopic CME with CVL by various tumor sub-site locations. Prospectively collected clinical data of consecutive patients who received laparoscopic colectomy for primary colon cancer between April 1995 and December 2010 from single surgeon were retrospectively reviewed. All of the included surgery was performed on the basis of CME with CVL principle with no-touch isolation technique. Data were analyzed and compared among three groups; patients who received right or extended right hemicolectomy (group A, n = 142), transverse colectomy or left or extended left hemicolectomy (group B, n = 59), and sigmoidectomy or anterior resection (group C, n = 210). Female patients were more common in group A (53.5% vs. 37.3% vs. 39.5%, p = 0.020). Other baseline characteristics were comparable. Operative time was shorter in group C than the other groups (309.0 ± 74.7 vs. 324.3 ± 89.1 vs. 280.1 ± 93.1 min, p = 0.000). There was no significant difference among groups in perioperative complication and patient recovery. Five-year overall survival, disease-free survival and local recurrence rate showed no difference for a median follow up period of 73 (1-120) months. In conclusion, laparoscopic tumor-specific CME and CVL for colon cancer can be performed with comparable short- and long-term outcomes regardless of tumor sub-site location except for the operative time.

Long-term oncologic outcomes of laparoscopic surgery for splenic flexure colon cancer are comparable to conventional open surgery.

PURPOSE: Few studies about laparoscopic surgery for splenic flexure colon cancer have been published. This study aims to compare the short- and long-term outcomes of laparoscopic surgery for splenic flexure colon cancer with those of conventional open surgery. METHODS: From January 2004 to December 2010, 51 consecutive patients who underwent curative resection for stages I-III splenic flexure colon cancer were enrolled. Thirty-three patients underwent laparoscopy-assisted colectomy, while 18 patients underwent conventional open colectomy. Short- and long-term outcomes of the 2 groups were compared. RESULTS: There were no differences in baseline characteristics, intra- and postoperative complications. The laparoscopy group showed longer operation time (median [interquartile range, IQR]: 295.0 [255.0-362.5] minutes vs. 180.0 [168.8-206.3] minutes, P < 0.001). In the laparoscopy group, return of bowel function was faster (median [IQR]: 3 [2-4] vs. 4 [3-5], P = 0.007) and postoperative hospital stay was shorter (median [IQR]: 9 [8-11] vs. 10.5 [9-19], P = 0.026). There were no statistically significant differences in overall survival rate (84.3% vs. 76.0%, P = 0.560) or disease-free survival rate (93.8% vs. 74.5%, P = 0.078) between the 2 groups. CONCLUSION: Laparoscopic surgery for splenic flexure colon cancer has better short-term outcomes than open surgery, as well as acceptable long-term outcomes. Laparoscopic surgery can be a safe and feasible alternative to conventional open surgery for splenic flexure colon cancer.

Learning curve for single-port laparoscopic colon cancer resection: a multicenter observational study.

BACKGROUND: The aim of this study was to investigate the learning curves (LCs) of single-port laparoscopic surgery (SPLS) for colon cancer using multidimensional statistical analyses. Although SPLS yields better cosmetic results and comparable short-term outcomes compared to conventional laparoscopic surgery, its technical difficulties make surgeons hesitant to try SPLS. Moreover, the LCs of SPLS for colon cancer are not well delineated. METHODS: Data were collected from patients who underwent SPLS for colon cancer in seven Korean institutions between May 2009 and May 2015. The LCs were analyzed using the moving average method and the cumulative sum control chart (CUSUM) for operation time and surgical failure. Surgical failure was defined as the any conversion, postoperative complications, or less than 12 harvested lymph nodes from surgical specimens. RESULTS: A total of 356 patients were included in this study. Six and three surgeons performed 282 anterior resections (ARs) and 74 right colectomies (RCs), respectively. On the basis of the moving average method and CUSUM for operation time and surgical failure, the LCs for AR were 18, 16, 35, 13, 36, and 13 cases for surgeons A-F, respectively. However, the LCs for RC were 6 and 15 cases for surgeons D and E, respectively, and were ambiguous for one surgeon. CONCLUSIONS: For surgeons experienced in conventional laparoscopic colorectal surgery, the LCs of SPLS for colon cancer ranged from 6 to 36 cases, which is shorter than the LCs reported for conventional laparoscopic surgery.

Predictive microRNAs for lymph node metastasis in endoscopically resectable submucosal colorectal cancer.

Accurate prediction of regional lymph node metastasis (LNM) in endoscopically resected T1-stage colorectal cancers (CRCs) can reduce unnecessary surgeries. To identify miRNA markers that can predict LNM in T1-stage CRCs, the study was conducted in two phases; (I) miRNA classifier construction by miRNA-array and quantitative reverse transcription PCR (qRT-PCR) using 36 T1-stage CRC samples; (II) miRNA classifier validation in an independent set of 20 T1-stage CRC samples. The expression of potential downstream target genes of miRNAs was assessed by immunohistochemistry. In the discovery analysis by miRNA microarray, expression of 66 miRNAs were significantly different between LNM-positive and negative CRCs. After qRT-PCR validation, 11 miRNAs were consistently significant in the combined classifier construction set. Among them, miR-342-3p was the most significant one (P=4.3×10-4). Through logistic regression analysis, we developed a three-miRNA classifier (miR-342-3p, miR-361-3p, and miR-3621) for predicting LNM in T1-stage CRCs, yielding the area under the curve of 0.947 (94% sensitivity, 85% specificity and 89% accuracy). The discriminative ability of this system was consistently reliable in the independent validation set (83% sensitivity, 64% specificity and 70% of accuracy). Of the potential downstream targets of the three-miRNAs, expressions of E2F1, RAP2B, and AKT1 were significantly associated with LNM. In conclusion, this classifier can predict LNM more accurately than conventional pathologic criteria and our study results may be helpful to avoid unnecessary bowel surgery after endoscopic resection in early CRC.

Comparison of Long-Term Outcomes Between Emergency Surgery and Bridge to Surgery for Malignant Obstruction in Right-Sided Colon Cancer: A Multicenter Retrospective Study.

BACKGROUND: Malignant obstruction in right-sided colon (MORC) has traditionally been treated by emergency resection with primary anastomosis. The aim of this study was to evaluate short-term postoperative and long-term oncologic outcomes according to the surgical approach adopted for MORC. METHODS: A total of 1785 patients who underwent curative surgery for stage II or III colon cancer in seven hospitals were reviewed retrospectively. Seventy-four of 1785 patients had MORC. We compared the postoperative outcome and long-term oncologic outcome between the emergency surgery (ES) group (49 patients) and the bridge to surgery (BS) group (25 patients) for 74 patients with MORC. RESULTS: There were no differences in the length of the distal and proximal resection margin (p = 0.820 and p = 0.620) or the number of metastatic lymph nodes (p = 0.221). There were no differences in flatus passage (p = 0.242), start of diet (p = 0.336), hospital stay (p = 0.444), or postoperative morbidity (p = 0.762). The 5-year overall survival rates were 73.2 % in the ES group and 90.7 % in the BS group (p = 0.172). Moreover, the 5-year disease-free survival rates were 71.9 % in the ES group and 76.2 % in the BS group (p = 0.929). CONCLUSIONS: On the basis of the above results, the postoperative course of the ES group was similar to that of the BS group. In addition, the long-term oncologic outcome of the BS group was similar or slightly better than that of the ES group. BS after colonic stent may be an alternative option for MORC.

Multimodal Assessments Are Needed for Restaging after Neoadjunvant Chemoradiation Therapy in Rectal Cancer Patients.

PURPOSE: Restaging after neoadjuvant treatment is done for planning the surgical approach and, increasingly, to determine whether additional therapy or resection can be avoided for selected patients. MATERIALS AND METHODS: Local restaging after neoadjuvant chemoradiation therapy (nCRT) was performed in 270 patients with locally advanced (cT3or4 or N+) rectal cancer. Abdomen and pelvic computed tomography (APCT) was used in all 270 patients, transrectal ultrasound (TRUS) in 121 patients, and rectal magnetic resonance imaging (MRI) in 65 patients. Findings according to imaging modalities were correlated with pathologic stage using Cohen's kappa (κ) to test agreement and intra-class correlation coefficient α to test reliability. RESULTS: Accuracy for prediction of ypT stage according to three imaging modalities was 45.2% (κ=0.136, α=0.380) in APCT, 49.2% (κ=0.259, α=0.514) in rectal MRI, and 57.9% (κ=0.266, α=0.520) in TRUS. Accuracy for prediction of ypN stage was 66.0% (κ=0.274, α=0.441) in APCT, 71.8% (κ=0.401, α=0.549) in rectal MRI, and 66.1% (κ=0.147, α=0.272) in TRUS. Of 270 patients, 37 (13.7%) were diagnosed as pathologic complete responder after nCRT. Rectal MRI for restaging did not predict complete response. On the other hand, TRUS did predict three complete responders (κ=0.238, α=0.401). CONCLUSION: APCT, rectal MRI, and TRUS are unreliable in restaging rectal cancer after nCRT. We think that multimodal assessment with rectal MRI and TRUS may be the best option for local restaging of locally advanced rectal cancer after nCRT.

Diffusion-weighted imaging: Apparent diffusion coefficient histogram analysis for detecting pathologic complete response to chemoradiotherapy in locally advanced rectal cancer.

PURPOSE: To investigate the usefulness of apparent diffusion coefficient (ADC) values derived from histogram analysis of the whole rectal cancer as a quantitative parameter to evaluate pathologic complete response (pCR) on preoperative magnetic resonance imaging (MRI). MATERIALS AND METHODS: We enrolled a total of 86 consecutive patients who had undergone surgery for rectal cancer after neoadjuvant chemoradiotherapy (CRT) at our institution between July 2012 and November 2014. Two radiologists who were blinded to the final pathological results reviewed post-CRT MRI to evaluate tumor stage. Quantitative image analysis was performed using T2 -weighted and diffusion-weighted images independently by two radiologists using dedicated software that performed histogram analysis to assess the distribution of ADC in the whole tumor. RESULTS: After surgery, 16 patients were confirmed to have achieved pCR (18.6%). All parameters from pre- and post-CRT ADC histogram showed good or excellent agreement between two readers. The minimum, 10th, 25th, 50th, and 75th percentile and mean ADC from post-CRT ADC histogram were significantly higher in the pCR group than in the non-pCR group for both readers. The 25th percentile value from ADC histogram in post-CRT MRI had the best diagnostic performance for detecting pCR, with an area under the receiver operating characteristic curve of 0.796. CONCLUSION: Low percentile values derived from the ADC histogram analysis of rectal cancer on MRI after CRT showed a significant difference between pCR and non-pCR groups, demonstrating the utility of the ADC value as a quantitative and objective marker to evaluate complete pathologic response to preoperative CRT in rectal cancer. J. Magn. Reson. Imaging 2016;44:212-220.

Novel Methods of Lymph Node Evaluation for Predicting the Prognosis of Colorectal Cancer Patients with Inadequate Lymph Node Harvest.

PURPOSE: Lymph node metastasis is an important factor for predicting the prognosis of colorectal cancer patients. However, approximately 60% of patients do not receive adequate lymph node evaluation (less than 12 lymph nodes). In this study, we identified a more effective tool for predicting the prognosis of patients who received inadequate lymph node evaluation. MATERIALS AND METHODS: The number of metastatic lymph nodes, total number of lymph nodes examined, number of negative metastatic lymph nodes (NL), lymph node ratio (LR), and the number of apical lymph nodes (APL) were examined, and the prognostic impact of these parameters was examined in patients with colorectal cancer who underwent surgery from January 2004 to December 2011. In total, 806 people were analyzed retrospectively. RESULTS: In comparison of different lymph node analysis methods for rectal cancer patients who did not receive adequate lymph node dissection, the LR showed a significant difference in overall survival (OS) and the APL predicted a significant difference in disease-free survival (DFS). In the case of colon cancer patients who did not receive adequate lymph node dissection, LR predicted a significant difference in DFS and OS, and the APL predicted a significant difference in DFS. CONCLUSION: If patients did not receive adequate lymph node evaluation, the LR and NL were useful parameters to complement N stage for predicting OS in colon cancer, whereas LR was complementary for rectal cancer. The APL could be used for prediction of DFS in all patients.

Laparoscopic Surgery for Transverse Colon Cancer: Short- and Long-Term Outcomes in Comparison with Conventional Open Surgery.

BACKGROUND: Published studies on laparoscopic surgery for transverse colon cancer are scarce. More studies are necessary to evaluate the feasibility, safety, and long-term oncologic outcomes of laparoscopic surgery for transverse colon cancer. SUBJECTS AND METHODS: From April 1996 to December 2010, 102 consecutive patients with stage II or III disease who had undergone curative resection for transverse colon cancer were enrolled. Seventy-nine patients underwent laparoscopy-assisted colectomy (LAC), whereas 23 patients underwent conventional open colectomy (OC). Short- and long-term outcomes of the two groups were compared. RESULTS: The OC group had a larger tumor size (7.6 ± 3.4 cm versus 5.2 ± 2.3 cm, P = .004) and more retrieved lymph nodes (26.4 ± 11.6 versus 17.5 ± 9.4, P = .002), without differences in resection margins. In the LAC group, return to diet was faster (4.5 ± 1.2 days versus 5.4 ± 1.8 days, P = .013), and postoperative hospital stay was shorter (12.1 ± 4.2 days versus 15.9 ± 4.8 days, P = .000). There were no differences in occurrence of intra- or postoperative complications. There were no statistically significant differences in overall survival rate (OS) or disease-free survival rate (DFS) between the two groups (5-year OS, 90.4% versus 90.5%, P = .670; 5-year DFS, 84.2% versus 90.7%, P = .463). CONCLUSIONS: Laparoscopic surgery for transverse colon cancer has better short-term outcomes compared with open surgery, with acceptable long-term outcomes. As in colorectal cancer of other sites, laparoscopic surgery can be a feasible alternative to conventional surgery for transverse colon cancer.

Comparative study between transanal tube and loop ileostomy in low anterior resection for mid rectal cancer: a retrospective single center trial.

PURPOSE: To investigate the efficacy and safety of the transanal tube (TAT) in preventing anastomotic leak (AL) in rectal cancer surgery. METHODS: Clinical data of the patients who underwent curative surgery for mid rectal cancer from February 2010 to February 2014 were reviewed retrospectively. Rectal cancers arising 5 to 10 cm above the anal verge were selected. Patients were divided into the ileostomy, TAT, or no-protection groups. Postoperative complications including AL and postoperative course were compared. RESULTS: We included 137 patients: 67, 35, and 35 patients were included in the ileostomy, TAT, and no-protection groups, respectively. Operation time was longer in the ileostomy group (P = 0.029), and more estimated blood loss was observed (P = 0.018). AL occurred in 5 patients (7.5%) in the ileostomy group, 1 patients (2.9%) in the TAT group, and 6 patients (17.1%) in the no-protection group (P = 0.125). Patients in the ileostomy group resumed diet more than 1 day earlier than those in the other groups (P = 0.000). Patients in the no-protection group had about 1 or 2 days longer postoperative hospital stay (P = 0.048). The ileostomy group showed higher late complication rates than the other groups as complications associated with the stoma itself or repair operation developed (P = 0.019). CONCLUSION: For mid rectal cancer surgery, the TAT supports anastomotic site protection and diverts ileostomy-related complications. Further large scale randomized controlled studies are needed to gain more evidence and expand the range of TAT usage.