Soo Yeun Park

Accuracy of preoperative MRI in predicting pathology stage in rectal cancers: node-for-node matched histopathology validation of MRI features.

BACKGROUND: Few studies that meticulously match individual lymph nodes seen on MRI with their precise histologic counterparts after total mesorectal excision have been reported. OBJECTIVE: The objective of this study was to determine whether preoperative MRI could detect lymph node metastases accurately in the node-by-node analysis. DESIGN: This was a prospective, observational cohort study. SETTINGS: The study was conducted at a tertiary-care hospital. PATIENTS: Forty patients with rectal cancer were enrolled. MAIN OUTCOME MEASURES: Specimens were assessed using MRI for clinical staging. After surgical resection of the tumor, the specimens were again imaged with ex vivo ultrasound scan to localize the perirectal node. The locations of each lymph node were precisely matched with its corresponding magnetic resonance image to enable a node-for-node comparison of magnetic resonance images and histologic findings. RESULTS: Agreement between MRI and histologic assessment of T stage was 82.5%. Of the 341 nodes harvested, 120 were too small (<3 mm) to be depicted on magnetic resonance images, and 18 of these contained metastasis (15%). A correlation between the results of MRI and histopathology was feasible for 205 lymph nodes, and the overall success rate of matching between the 2 techniques was 91.1% (205 of 221). Preoperative MRI revealed a node-by-node sensitivity and positive predictive value of 58.0%, and 61.7%. There was no difference in the diagnostic accuracy between the primary surgery subgroup and preoperative radiation subgroups. LIMITATIONS: The study is limited by its heterogeneity of cohorts including the subgroup with preoperative chemoradiation and the lack of preoperative ultrasound assessment. CONCLUSIONS: Preoperative MRI was moderately accurate for the prediction of mesorectal lymph node metastasis. Moreover, preoperative MRI was insufficient for detecting small lymph nodes (<3 mm) with metastasis.

Multidimensional analysis of the learning curve for robotic total mesorectal excision for rectal cancer: lessons from a single surgeon's experience.

BACKGROUND: Little data are available about the learning curve for robotic rectal resection. OBJECTIVE: The purpose of this work was to provide a multidimensional analysis of the learning process in patients undergoing robotic total mesorectal excision for rectal cancer. DESIGN: This was a retrospective review of a prospectively collected database designed to evaluate the results of robotic rectal resection. SETTINGS: The study was conducted at a tertiary-care hospital. PATIENTS: From December 2007 to August 2012, 167 patients who underwent robotic total mesorectal excision for rectal cancer were included. MAIN OUTCOME MEASURES: A single hybrid variable including operative time, conversion, perioperative morbidity, and circumferential margin was generated to measure the success of the procedure. A moving average method for operative time and a risk-adjusted cumulative sum analysis were used to derive the learning curve. RESULTS: Overall conversion was noted in 2 cases (1.2%). The cumulative sum plot of a single hybrid variable representing the success of each operation demonstrated that the composite event was more frequent at the beginning of the series and began to decrease after 32 cases. The moving average for robotic console time decreased steadily and showed 2 plateaus; the first plateau was noted after 33 cases, and the second plateau was noted after 72 cases. The learning process was divided into 3 phases based on 2 cutoff points. The robotic console time decreased significantly with each phase (p < 0.001). Complicated rectal cancer was more frequent in the later phases; however, the incidence of postoperative complications remained constant throughout the series (p = 0.82). LIMITATIONS: This study is limited by a single surgeon’s experience. CONCLUSIONS: The learning process for robotic total mesorectal excision has a greater effect on the first 32 cases. These results help form a basis for performance monitoring of robotic total mesorectal excision.

Expression of aquaporin-1, aquaporin-3, and aquaporin-5 correlates with nodal metastasis in colon cancer

Objectives: The clinical significance of aquaporin-1 (AQP1), aquaporin-3 (AQP3), and aquaporin-5 (AQP5) expression was analyzed in a large number of patients with colon cancer. Methods: AQP1, AQP3, and AQP5 expression was investigated based on the immunohistochemistry of tissue microarray specimens from 486 colon cancer patients who underwent curative surgery. Scores were given to the staining intensity and percentage of positive cells, and the staining score was defined as the sum of these scores then used to categorize the AQP expression as negative, weakly AQP-positive, or strongly AQP-positive. Results: A total of 298 (61.3%) patients were identified as strongly AQP1-positive (staining score ≥6), while 38 (7.8%) were strongly AQP3-positive and 145 (29.8%) were strongly AQP5-positive. The overexpression of AQP1, AQP3, and AQP5 was significantly correlated with lymph node metastasis in a multivariate logistic analysis (AQP1, p = 0.026; AQP3, p = 0.023; AQP5, p = 0.003). While the multivariate survival analysis, which included age, histology, TNM stage, and CEA level showed that the expression of AQP1, AQP3, and AQP5 had no effect on the overall survival and disease-free survival. Conclusions: The current study found a significant correlation between AQP1, AQP3, and AQP5 expression and lymph node metastasis in patients with surgically resected colon cancer.

Robot-assisted right colectomy with lymphadenectomy and intracorporeal anastomosis for colon cancer: technical considerations.

Background: A surgical robot (the da Vinci system) was developed to overcome the disadvantages of laparoscopic surgery, and applications of this system have been widely used. In this study, we present our standardized technique of robotic right colectomy with lymphadenectomy and intracorporeal anastomosis, with an assessment of feasibility in a series of 15 patients. Methods: All robotic right colectomies with lymphadenectomy were performed by a single surgeon between April 2009 and March 2010. Robotic assistance was used for the colonic mobilization, lymphadenectomy, and bowel reconstruction. Patient demographics, perioperative clinical outcomes, and pathologic results were reviewed. Results: Robotic-assisted right colectomy was successfully performed on 15 patients with colon cancer. The total operative time was 201.4±8.1 minutes, with a mean robotic time of 114.4±7.5 minutes. No patient required conversion to conventional surgery. The median time to clear liquid intake was 3 days, and the median length of stay after surgery was 8 days. The mean tumor diameter was 3.0±0.3 cm, and the mean number of harvested lymph nodes was 24.2±15.5. Tumors were diagnosed as stage I in 7 patients, stage II in 5, and stage III in 3. Conclusions: Robotic right colectomy with lymphadenectomy can be performed successfully and safely. The robotic system was safe and feasible for the following steps: accurate node dissection, suturing for intracorporeal anastomosis, and natural orifice specimen extraction. Further comparative studies must be performed to verify the advantages of robotic surgery over conventional laparoscopic surgery.

Initial Clinical Experience with Robotic Lateral Pelvic Lymph Node Dissection for Advanced Rectal Cancer

Purpose This study was conducted to evaluate the technical feasibility and safety of robotic extended lateral pelvic lymph node dissection (LPLD) in patients with advanced low rectal cancer. Methods A review of a prospectively-collected database at Kyungpook National University Medical Center from January 2011 to November revealed a series of 8 consecutive robotic LPLD cases with a preoperative diagnosis of lateral node metastasis. Data regarding patient demographics, operating time, perioperative blood loss, surgical morbidity, lateral lymph node status, and functional outcome were analyzed. Results In all eight patients, the procedures were completed without conversion to open surgery. The mean operative time of extended pelvic node dissection was 38 minutes (range, 20 to 51 minutes), the mean number of lateral lymph nodes harvested was 4.1 (range, 1 to 13), and 3 patients (38%) were found to have lymph node metastases. Postoperative mortality and morbidity were 0% and 25%, respectively, but, there was no LPLD-related morbidity. The mean hospital stay was 7.5 days (range, 5 to 12 days). Conclusion Robotic LPLD is safe and feasible, with the advantage of being a minimally invasive approach. Further large-scale studies comparing robotic and conventional surgery with long-term follow-up evaluation are needed to confirm these findings.

Predictive factors and the prognosis of recurrence of colorectal cancer within 2 years after curative resection

Purpose Because predicting recurrence intervals and patterns would allow for appropriate therapeutic strategies, we evaluated the clinical and pathological characteristics of early and late recurrences of colorectal cancer. Methods Patients who developed recurrence after undergoing curative resection for colorectal cancer stage I-III between January 2000 and May 2006 were identified. Early recurrence was defined as recurrence within 2 years after primary surgery of colorectal cancer. Analyses were performed to compare the clinicopathological characteristics and overall survival rate between the early and late recurrence groups. Results One hundred fifty-eight patients experienced early recurrence and 64 had late recurrence. Multivariate analysis revealed that the postoperative elevation of carbohydrate antigen 19-9 (CA 19-9), venous invasion, and N stage correlated with the recurrence interval. The liver was the most common site of early recurrence (40.5%), whereas late recurrence was more common locally (28.1%), or in the lung (32.8%). The 5-year overall survival rates for early and late recurrence were significantly different (34.7% vs. 78.8%; P < 0.001). Survival rates after the surgical resection of recurrent lesions were not different between the two groups. Conclusion Early recurrence within 2 years after surgery was associated with poor survival outcomes after colorectal cancer recurrence. An elevated postoperative CA 19-9 level, venous invasion, and advanced N stage were found to be significant risk factors for early recurrence of colorectal cancer.

Influence of surgical manipulation and surgical modality on the molecular detection of circulating tumor cells from colorectal cancer

Purpose The aim of this study was to evaluate the relationship between the detection of circulating tumor cell molecular markers from localized colorectal cancer and the time-course of a surgical manipulation or surgical modality. Methods From January 2010 to June 2010, samples from the peripheral blood and the inferior mesenteric vein were collected from 42 patients with cancer of the sigmoid colon or rectum. Pre-operative, intra-operative (both pre-mobilization and post-mobilization), and post-operative samples were collected. We examined carcinoembryonic antigen (CEA) mRNA and cytokeratin-20 (CK20) mRNA by real-time reverse-transcriptase polymerase chain reaction. Changes in mRNA detection rates were analyzed according to the time of blood sample collection, the surgical modality, and patient clinicopathological features. Results mRNA expression rates before surgical resection did not differ between blood samples from the peripheral and inferior mesenteric veins. The detection rate for CEA and CK20 mRNA showed a tendency to increase after operative mobilization of the cancer-bearing bowel segment. Furthermore, the cumulative detection rates for CEA and CK20 mRNA increased significantly over the course of surgery (pre-mobilization vs. post-mobilization). The cumulative detection rate decreased significantly after surgical resection compared with the pre-operative rates. However, no significant difference was observed in the detection rates between different surgical modalities (laparoscopy vs. open surgery). Conclusion The results of this study suggest that surgical manipulation has a negative influence on the dissemination of circulating tumor cells during operations on localized colorectal cancer. However, the type of surgical technique did not affect circulating tumor cells.

A case of giant rectal villous tumor with severe fluid-electrolyte imbalance treated by laparoscopic low anterior resection

McKittrick-Wheelock syndrome is a disorder caused by fluid and electrolyte hypersecretion from a colorectal tumor. To present the case of a patient with a giant rectal villous tumor with McKittrick-Wheelock syndrome who was successfully treated with laparoscopic surgery. The case of a 59-year-old man who came to the emergency department with syncope, prerenal azotemia, and electrolyte disturbances with a background of chronic diarrhea is reported. His condition was the result of fluid and electrolyte hypersecretion caused by rectal villotubular adenomas. Laparoscopic low anterior resection and subsequent volume and electrolyte replacement therapy resulted in complete recovery. A microscopic examination revealed multiple, well-differentiated adenocarcinomas arising in villotubular adenomas. Laparoscopic surgical resection is a feasible therapeutic modality for McKittrick-Wheelock syndrome.

Clinical Implication of Serine Metabolism-Associated Enzymes in Colon Cancer.

Purpose: Recently, enzymes of the serine synthetic pathway (SSP) have been suggested as key player in the metabolic adaptation of oncogenesis. We assessed the expression of enzymes of the SSP in colonic tumor tissue (TT) and paired normal tissue (pNT) and the prognostic implications. Methods: From 2006 to 2010, we included 486 patients with colon cancer who underwent curative surgery at Kyungpook National University Hospital. Phosphoglycerate dehydrogenase (PHGDH), pyruvate dehydrogenase kinase (PDK) 1, PDK2, pyruvate kinase M2 (PKM2), and phosphoserine aminotransferase (PSAT) expression were investigated by immunohistochemical staining (IHC) in TT and pNT. The IHC values were calculated by multiplying intensity by proportion. The final score was classified as follows: 0-2 as negative and 3-12 as positive. Results: During the median follow-up duration of 55.5 months (37.4-90.6), 78 patients experienced recurrence. The expression of PHGDH, PDK1, and PSAT was significantly higher in TT than pNT (p < 0.001 for each). The univariate analysis for relapse-free survival revealed that TT PDK2 positivity was the only positive prognostic factor (p = 0.023). However, the expression of TT PDK2 did not represent a prognostic value in multivariate analysis. Conclusions: In conclusion, PHGDH, PDK1, and PSAT were significantly increased in colonic TT compared with pNT. The prognostic implication of these enzymes needs to be further investigated.

Comparison of Surgical Skills in Laparoscopic and Robotic Tasks Between Experienced Surgeons and Novices in Laparoscopic Surgery: An Experimental Study

Purpose Robotic surgery is known to provide an improved technical ability as compared to laparoscopic surgery. We aimed to compare the efficiency of surgical skills by performing the same experimental tasks using both laparoscopic and robotic systems in an attempt to determine if a robotic system has an advantage over laparoscopic system. Methods Twenty participants without any robotic experience, 10 laparoscopic novices (LN: medical students) and 10 laparoscopically-experienced surgeons (LE: surgical trainees and fellows), performed 3 laparoscopic and robotic training-box-based tasks. This entire set of tasks was performed twice. Results Compared with LN, LEs showed significantly better performances in all laparoscopic tasks and in robotic task 3 during the 2 trials. Within the LN group, better performances were shown in all robotic tasks compared with the same laparoscopic tasks. However, in the LE group, compared with the same laparoscopic tasks, significantly better performance was seen only in robotic task 1. When we compared the 2 sets of trials, in the second trial, LN showed better performances in laparoscopic task 2 and robotic task 3; LE showed significantly better performance only in robotic task 3. Conclusion Robotic surgery had better performance than laparoscopic surgery in all tasks during the two trials. However, these results were more noticeable for LN. These results suggest that robotic surgery can be easily learned without laparoscopic experience because of its technical advantages. However, further experimental trials are needed to investigate the advantages of robotic surgery in more detail.