Abstract:Single-incision laparoscopic surgery (SILS) technique is a newly developed surgical technique and, with continuous understanding and mastery of this technique, its application is increasingly extended in the field of abdominal surgery especially in the subfield of colorectal surgery. Here, the authors give a commentary on the application status, technical characteristics and development prospects of SILS technique in colorectal surgery.

Abstract:疝，腹股沟；手术后并发症；老年人

Abstract:Objective: To evaluate the safety of applying the “Wait-and-See” (W&S) strategy in rectal cancer patients with clinical complete response (cCR) after neoadjuvant chemoradiotherapy (NCRT). Methods: The clinical studies comparing using W&S strategy and radical surgery (RS) in rectal cancer patients with cCR after NCRT were collected by searching several foreign databases. After screening for inclusion, data extraction and quality assessment, Meta-analysis was performed on the variables that included local recurrence (LR), distant metastasis (DM), cancer-related death (CRD), disease-free survival (DFS) and overall survival (OS) by using Stata/SE 12.0 software. Results: Eleven studies with moderate to high quality were included, involving 847 patients, with 378 cases in W&S group and 469 cases in RS group. The results of Meta-analysis showed that W&S group was superior to RS group in terms of LR (RR=6.20, 95% CI=2.68–14.30, P=0.000), 2-year OS (RR=1.05, 95% CI=1.01–1.10, P=0.029) and 3-year OS (RR=1.09, 95% CI=1.03–1.15, P=0.004), while no differences were noted with regard to DM, CRD, or 2-, 3- and 5-year DFS as well as 5-year OS between the two groups (all P>0.05). Conclusion: W&S strategy is safe and feasible for some patients who achieved cCR after NCRT, but this strategy requires rigorous screening criteria and standardized follow-up program. Meanwhile, large sample size and multicentric, prospective randomized controlled trials are urgently expected to verify this treatment approach.

Abstract:Objective: To compare the efficacy of extraperitoneal and transperitoneal colostomy after laparoscopic Miles’ procedure. Methods: The clinical studies comparing the efficacy of extraperitoneal and transperitoneal colostomy after laparoscopic Miles’ operation publicly published before August 2017 were collected by searching several national and international databases. Meta-analysis was performed on relevant variables by using RevMan 5.3 software. Results: A total of 15 studies involving 1 162 patients were included, with 615 cases in extraperitoneal group and 547 cases in transperitoneal group. The results of pooled Meta-analysis showed that except the increased incidence of stomal edema (OR=5.19, 95% CI=2.15–12.53, P=0.0002), the incidence of parastomal hernia (OR=0.10, 95% CI=0.04–0.22, P<0.00001), incidence of stoma necrosis (OR=0.37, 95% CI=0.16–0.86, P=0.02), incidence of stoma prolapse (OR=0.22, 95% CI=0.09–0.57, P=0.002), incidence of internal hernia (OR=0.23, 95% CI=0.06–0.81, P=0.02), incidence of stoma retraction (OR=0.25, 95% CI=0.07–0.81, P=0.02), and incidence of stoma mucocutaneous separation (OR=0.30, 95% CI=0.12–0.76, P=0.01) were all significantly decreased, with reduced length of postoperative hospital stay (MD=–0.70, 95% CI=–1.14––0.27, P=0.002) and improved sensation of defecation (OR=20.32, 95% CI=9.05–45.62, P<0.00001) in transperitoneal group compared with extraperitoneal group. There were no differences in variables that included stoma infection, operative time, time of colostomy creation, stoma constriction, intestinal obstruction, time to first postoperative gas passage, intraoperative blood loss, stoma bleeding and parastomal inflammation between the two groups (all P>0.05). Conclusion: Transperitoneal colostomy has better efficacy than that of extraperitoneal colostomy after laparoscopic Miles’ operation.

Abstract:Objective: To investigate the application efficacy of laparoscopic modified intersphincteric resection (ISR) combined with transanal pull-through in anus-preserving operation for low rectal cancer. Methods: The clinical data of 11 patients with low rectal cancer undergoing laparoscopic modified ISR combined with transanal pull-through from April 2016 to June 2017 were retrospectively analyzed. Results: Operation was successfully performed in all the 11 patients. The average operative time was 215 (18–320) min, the average blood loss was 52 (30–250) mL, and the average length of postoperative hospital stay was 11.6 (9–15) d. No anastomotic leakage, presacral infection, anastomotic stricture or postoperative hemorrhage occurred. The number of obtained lymph nodes in single specimen ranged from 12 to 26 with an average number of 15. The 11 patients were followed up for 4 to 16 months, with an average period of 10 months. No surgery-associated complications were found, and no local recurrence or metastasis occurred. The anal functions of the patients were satisfactorily recovered after 6 months. Conclusion: Laparoscopic modified ISR combined with transanal pull-through is an ideal procedure for low rectal cancer with anus preservation. It offers satisfactory anal function and effect with no requirement of preventive colostomy, and can completely avoid the occurrence of anastomotic leakage, with the advantages of small trauma, quick recovery and low costs.

Abstract:Objective: To investigate the influences of using methylene blue injection into the superior rectal artery during laparoscopic rectal resection after neoadjuvant chemoradiotherapy on number of harvested lymph nodes and postoperative male sexual function and urination function in male rectal cancer patients. Methods: Ninety-six rectal cancer male patients undergoing laparoscopic radical resection after synchronous neoadjuvant chemotherapy and radiotherapy in Xiangtan Central Hospital and Chen Xinghai Hospital during March 2013 to April 2017 were enrolled. The patients were randomly assigned to study group and control group, with 48 cases in each group. Patients in study group were injected with 8 mL of 1% methylene blue into the superior rectal artery prior to radical resection, and those in control group underwent radical surgery directly. The numbers of lymph node dissected, and postoperative sexual function (including erection and ejaculation) and urination function between the two groups of patients were compared. Results: There was no significant difference in the procedures performed in the two groups (P>0.05). The number of lymph nodes removed was significantly higher in study group than that in control group (15.04±4.063 vs. 12.23±2.991, P<0.05); the numbers of cases with grade I, II and III postoperative 1-year ejaculation function were 41 (85.4%), 7 (14.6%) and 0 (0) in study group, and were 31 (64.6%), 13 (27.1%) and 4 (8.3%) in control group, the numbers of cases with grade I, II, III postoperative 1-year erection function were 42 (87.5%), 6 (12.5%) and 0 (0) in study group and were 32 (66.7%), 15 (31.3%) and 1 (2.1%) in control group, and the numbers of cases with grade I, II, III and IV postoperative 1-year urination function were 35 (72.9%), 12 (25.0%) , 1 (2.1%) and 0 (0) in study group and were 26 (54.2), 13 (27.1%), 5 (10.4%) and 4 (8.3%) in control group. The results of statistical analysis showed the postoperative 1-year ejaculation function, erection function and urination function were significantly superior in study group than those in control group (all P<0.05). Conclusion: For rectal cancer patients undergoing radical resection after neoadjuvant chemoradiotherapy, methylene blue injection into the superior rectal artery can help to clarify the surgical plane and increase the lymph node dissection rate as well as reduce damages of the pelvic nerves, and thereby protect the sexual function and urinary function of male patients.

Abstract:Objective: To investigate the feasibility and safety of laparoscopic transabdominal preperitoneal (TAPP) repair in treatment of irreducible inguinal hernia. Methods: The surgical and follow-up data of 118 patients with irreducible inguinal hernia undergoing laparoscopic TAPP from January 2011 to December 2016 in the Department of Hernia and Abdominal Wall Surgery of Beijing Chaoyang Hospital were retrospectively analyzed. Results: Of the 118 patients, 90 cases (76.3%) underwent standard TAPP procedure, and 28 cases (23.7%) underwent small incision-assisted TAPP. In the entire group of patients, the operative time was 50(40–65)min, intraoperative blood loss was 5(3–10) mL, length of postoperative hospital stay was 2(1–3) d, and hospitalization cost was 9 696(9 012–11 456) yuan. The intraoperative complications occurred in 4 patients (3.4%), including vas deferens injury in one case (0.8%), spermatic vessel injury in 2 cases (1.7%) and inferior epigastric artery injury in one case (0.8%). Perioperative complications occurred in 31 cases (26.3%), including dysuria in 8 cases (6.8%), scrotum hematoma in one case (0.8%), wound pain in 21 (17.8%) cases and cognitive disorder in one case (0.8%). Twelve months of follow-up was completed in all patients, and no recurrence or infections occurred; complications occurred in 48 patients (40.7%) during period of follow-up, including seroma in 33 (28.0%) cases, foreign body sensation in 3 cases (2.5%) and chronic pain in one case (0.8%). The incidence of perioperative wound pain in patients undergoing small incision-assisted TAPP was higher than that in patients undergoing standard TAPP (46.4% vs. 8.9%, P<0.05), but no statistical differences were observed in other variables between the two procedures (all P>0.05). Conclusion: Laparoscopic TAPP is safe and feasible for the treatment of irreducible inguinal hernia under the premise of a clear diagnosis. However, the procedure should be decided in accordance with the specific conditions during operation.

Abstract:Objective: To investigate the clinical efficacy of ventral hernia repair for patients with liver cirrhosis or after liver transplantation. Methods: The clinical data of 35 ventral hernia patients with liver cirrhosis or after liver transplantation undergoing elective hernia repair in the First Affiliated Hospital of Sun Yat-Sen University from January 2006 to December 2016 were analyzed retrospectively. Of the patients, 18 cases were inguinal hernia, 10 cases were ventral incisional hernia, 5 cases were umbilical hernia, one case had concomitant umbilical hernia and incisional hernia and one case had hernia of the abdominal linea alba. The incidence of complications and recurrence of hernia after herniorrhaphy as well as the relevant clinical variables of the patients were analyzed. Results: Of the 35 patients, 27 cases were males and 8 cases were females, with an average age of (59.0±9.42) years; 16 cases (45.7%) had prolonged prothrombin time, 16 cases (45.7%) had hypoproteinemia, and 24 cases (68.5%) had ascites. the preoperative Child-Pugh classification was regarded as grade A in 16 cases of (45.7%) grade B in 18 cases (51.4%), and grade C in one case (2.8%); the preoperative ASA classification was defined as grade II in 11 cases (31.4%), grade III in 20 cases (57.1%), and grade IV in 4 cases (11.4%). Operation was successfully completed in all patients, and no perioperative death occurred. The average operative time and intraoperative blood loss were (97.0±18.7) min and (30.0±5.0) mL for inguinal hernia, (125±33.5) min and (100.5±23.5) mL for incisional hernia, and were (106.0±45.1) min and (40.5±20.5) mL for umbilical hernia, respectively. The median length of postoperative hospital stay was 8 (1–63) d. The overall incidence of postoperative complications was 22.8%, which included seroma in 2 cases (5.7%), hematoma in 4 cases (11.4%), wound infection in one case (2.9%), and surgical site infection in 2 cases (5.7%). The follow-up rate was 65.7% (23/35) and the median follow-up time was 25 months. Discomfort in the surgical region was reported in 2 cases (8.7%) and chronic pain was not reported in any of them. Recurrence occurred in 4 cases (17.4%), which included inguinal hernia and incisional hernia with 2 cases (8.7%) each. Conclusion: Elective herniorrhaphy for ventral hernia complicated with liver cirrhosis or after liver transplantation is safe and effective, but the incidence of postoperative complications and recurrence rate are relatively high.

Abstract:Objective: To examine the safety and efficacy of laparoscopic hiatal hernia repair. Methods: The clinical data of 51 patients undergoing laparoscopic hiatal hernia repair from July 2012 to July 2016 were retrospectively analyzed. Results: In all the 51 patients, laparoscopic hiatal herniorrhaphy was uneventfully performed, and a mesh was used to reinforce hiatal closure during operation. Dor fundoplication was performed at the same time in those without obvious contraindications. The average operative time was (100±19.6) min, the average blood loss was (28±15.4) mL, and the average length of hospital stay was 2 d. The symptoms caused by compression of the hernia sac contents such as chest pain and choke after eating were significantly alleviated, and the reflux-related symptoms such as acid regurgitation and heartburn were significantly improved after operation. No serious complications occurred, and all patients returned to normal diet within four weeks after operation. Follow-up was conducted for an average of 32 months, and no recurrence or mesh-related complications were noted. Conclusion: Laparoscopic hiatal hernia repair is a safe and effective procedure, and mesh reinforcement after hiatal closure can reduce the recurrence of hiatal hernia.

Abstract:Objective: To investigate the expression of miR-124 in colon cancer and its actions on the biological behaviors of colon cancer cells as well as the potential mechanism. Methods: The expressions of miR-124 in colon cancer tissue and cells were examined by qRT-PCR. In colon cancer cells after up-regulating miR-124 expression through lentiviral vector transfection technique, the change in apoptosis was examined by flow cytometry. Nude mice were injected with colon cancer cells of different miR-124 expression levels, and then, the pulmonary metastasis and survival time were observed. The target genes of miR-124 were predicted by bioinformatic analysis, followed by identification and verification through dual luciferase reporter assay and a series of in vitro and in vivo experiments. Results: The miR-124 expression was significantly reduced in colon cancer tissue, and its expression was significantly associated with the tumor size, tumor stage and lymph node metastasis (all P<0.05). The miR-124 expression level was decreased with the increase of the degree of malignancy of the colon cancer cells. After up-regulation of miR-124 expression, the apoptosis of colon cancer cells was significantly increased, pulmonary metastasis was inhibited and survival time was prolonged in the nude mice (all P<0.05). ITGB1 was suggested as the potential target gene for miR-124. In colon cancer cells, down-regulating ITGB1 expression showed the similar effects as those exerted by up-regulating miR-124 expression. There was a negative correlation between miR-124 and ITGB1 expressions in colon cancer tissue (r=–0.4936, P=0.002). Conclusion: The miR-124 expression is down-regulated in colon cancer, with accordingly increased expression of its target gene ITGB1, which promotes the growth as well as the invasion and metastasis of the colon cancer cells.

Abstract:Objective: To investigate the effects of FH535 on the self-renewal, migration and invasion of colorectal cancer stem cells (CRC-CSCs) and the mechanism. Methods: CD133+CD44+ CSCs were isolated by fluorescence-activated cell sorting (FACS) from the human DLD-1 colorectal cancer cell line. CRC-CSCs were treated with different concentrations of FH535 (20, 30, 40 μmol/L) and the half maximal inhibitory concentration (IC50) value was calculated. CRC-CSCs were treated with concentration of FH535, using untreated CRC-CSCs as control, and then, their self-renewal capacity was determined by limiting dilution assay (LDA) and sphere-forming assay, the migration and invasion abilities were measured by Transwell assay and real-time cell analysis (RTCA), and the mRNA and protein expressions of molecules involved in Wnt/β-catenin signaling pathway as well as the downstream molecules were evaluated by qRT-PCR and flow cytometry, respectively. Results: The IC50 of CRC-CSCs to FH535 was determined to be 40 μmol/L. In CRC-CSCs treated with 40 μmol/L FH535 compared with those in control group, the sphere forming capacity was significantly decreased (57.33 vs. 313.67, P<0.01) and CRC-CSCs ratio was significantly reduced (11.60/100 vs. 75.50/100, P<0.05), the migration (Transwell: 10.66 vs. 90.00; RTCA: 0.17 vs0.37) and invasion (Transwell: 8 vs. 20; RTCA: 0.14 vs. 0.37) were all significantly inhibited (all P<0.01), and the mRNA and protein expressions of LEF1 and AXIN1 in Wnt/β-catenin signaling pathway and the downstream molecules c-myc, VEGF, cyclin D1 and survivin were all significantly down-regulated (all P<0.01). Conclusion: FH535 can weaken the abilities of self-renewal, migration and invasion of CRC-CSCs, and the mechanism may be probably associated with its inhibiting the activity of Wnt/β-catenin signaling pathway.

Abstract:Objective: To investigate the expressions of liver X receptor α (LXRα) and proteasome activator 28γ (PA28γ) in gastric cancer and their effects on the growth of gastric cancer cells. Methods: The mRNA and protein expressions of LXRα and PA28γ in 35 specimens of gastric cancer and paired adjacent tissue were determined by qRT-PCR and immunohistochemical staining. The relations of their protein expressions with the clinicopathologic factors of the patients, and their correlationship were analyzed. In gastric AGS cells after overexpression with LXRα, the changes in cell cycle, growth in nude mice and expressions of LXRα and that of PA28γ were analyzed by flow cytometry, qRT-PCR and Western blot, respectively. Results: Both mRNA and protein expressions of LXRα were significantly decreased, and both mRNA and protein expressions of PA28γ were significantly increased in gastric cancer tissue compared with adjacent tissue (all P<0.05); the expressions of either LXRα or PA28γ showed no significant associations with the main clinicopathologic factors of the gastric cancer patients (all P>0.05); there was a significant negative correlation between LXRα and PA28γ protein expressions in gastric cancer tissue (r=–0.452, P=0.006). In gastric AGS cells after overexpression with LXRα, the LXRα mRNA expression was significantly increased, while the mRNA and protein expressions of PA28γ were significantly reduced, the cell cycle process was significantly blocked, the growth in nude mice was significantly suppressed, with significantly up-regulated mRNA and protein expressions of LXRα and down-regulated mRNA and protein expressions of PA28γ in the tissue of the transplanted tumor (all P<0.05). Conclusion: LXRα expression is down-regulated in gastric cancer with synchronous up-regulated PA28γ expression, and their growth and decline may probably regulate the growth of gastric cancer cells through affecting the cell cycle process.

Abstract:Objective: To investigate the feasibility and short-term safety of robotic assisted gastrectomy (RAG) for the treatment of gastric cancer. Methods: The clinical data of 235 gastric cancer patients undergoing radical gastrectomy between January 2017 and February 2018 were retrospectively analyzed. Of the patients, 100 cases underwent RAG and 135 cases underwent laparoscopic- assisted gastrectomy (LAG). The relevant clinical variable between the two groups of patients were compared. Results: The demographic characteristics and clinicopathological features were matched between the two groups. Either in the entire group or in the subgroups stratified by BMI, resection type and age, the length of hospitalization was reduced, time to first anal gas passage was shortened, and the number of dissected lymph nodes was increased in RAG group compared with LAG group (all P<0.05). Further analyses showed that the increased number of dissected lymph nodes in RAG group mainly depended on the increased average numbers of dissected lymph nodes in No. 6, 7, 10, 11p and 14v lymph nodes (all P<0.05). There was no significant difference between the two groups in terms of operative time, surgical bleeding, time to liquid diet and incidence of postoperative complications (all P>0.05). Conclusion: RAG is a safe and feasible method for the treatment of gastric cancer, but its long-term results and prognosis still need to be verified by further studies.

Abstract:Objective: To investigate the Clavien-Dindo classification and risk factors for postoperative complications of laparoscopy-assisted radical gastrectomy (LAG) for gastric cancer. Methods: The data of 156 patients undergoing LAG for gastric cancer between January 2014 and November 2017 were retrospectively analyzed. The postoperative complications were stratified using the Clavien-Dindo classification system, and the risk factors for postoperative complications and the influential factors for Clavien-Dindo classification were also determined. Results: Of the 156 patients, postoperative complications occurred in 27 cases (17.3%), with Clavien-Dindo grade I in 3 cases, grade II in 15 cases, grade III in 8 cases, and grade V in 1 case, respectively. The most common complications included anastomotic fistula, intestinal obstruction and hemorrhage. The results of univariate analysis indicated that the sex, BMI, concomitant underlying diseases, ASA grade, preoperative hemoglobin level, operative time, type of surgery, the serum level of c-reactive protein (CRP) on postoperative day (POD) 3 of the patients were associated with the occurrence of postoperative complications of LAG (all P<0.05). The results of multivariate analysis demonstrated that BMI (≥25 kg/m2), anastomosis method (Billroth II and Roux-en-Y method) and CRP level on POD 3 (≥170 mg/L) were the independent risk factors for postoperative complications of LAG (all P<0.05). BMI, anastomosis method and CRP level on POD 3 were also the factors affecting the Clavien-Dindo grade of the postoperative complications of the patients (all P<0.05). Conclusion: The postoperative complications of LAG are Clavien-Dindo grade II, and the BMI, anastomosis method and CRP on POD 3 are important factors for the postoperative complications of LAG and their severities.

Abstract:Objective: To investigate the safety and feasibility of laparoscopic radical total gastectomy via complete left approach. Methods: The clinical data of 36 patients with advanced gastric cancer undergoing laparoscopic radical total gastectomy via complete left approach from January 2016 to July 2017 were retrospectively analyzed. Results: Of the 36 patients, 20 cases were males and 16 cases were females, with an average age of (61.7±13.3) years; 19 cases had cancer of proximal stomach and 17 cases had cancer of middle third of stomach. Operation was successfully performed in all of the 36 patients who underwent operation; none of the patients required open conversion or combined excision of the spleen and other organs and there was no occurrence of intraoperative complications or serious postoperative complications. The average operative time was (228.6±45.9) min, and the average intraoperative blood loss was (82.7±25.5) mL. Postoperative pathological results showed that the average number of lymph nodes harvested was 35.5±6.2, with an average positive number of 3.9±2.1; the tumor stages included IIA in 1 case (8.3%), IIB in 2 cases (16.7%), IIIA in 4 cases (33.3%), IIIB in 3 cases (25.0%), and IIIC in 2 cases (16.7%). After operation, wound infection occurred in 2 patients (5.6%), inflammatory bowel obstruction occurred in 2 patients (5.6%), and pulmonary infection occurred in 1 case (2.8%), which were all cured with conservative treatment. Conclusion: Laparoscopic radical total gastectomy via complete left approach is safe and feasible.

Abstract:Objective: To investigate the diagnostic value of capsule endoscopy (CE) examination for small intestinal diseases and compare the merits and drawbacks of different CE examination systems. Methods: Four hundred and seventeen patients undergoing CE examination for gastrointestinal symptoms in the Second Xiangya Hospital of Central South University from March 2010 to December 2015 were enrolled. The working time, transit times in the stomach and small bowel, examination completion rate, positive diagnostic rate, lesion detection rate and capsule retention rate were compared between domestic and foreign imported CE examination systems, and the constitutions of the diagnosed small bowel diseases in patients of different ages and undergoing examination for different reasons were also analyzed. Results: In foreign imported CE group compared with domestic CE group, the working time, and transit times in the stomach and small bowel were prolonged, and the examination completion rate was increased (88.8% vs. 84.0%) (all P<0.05), but the positive detection rates (76.6% vs. 70.5%), lesion detection rates (89.8% vs. 90.1%) and capsule retention rate (0.5% vs. 1.0%) showed no significant differences (all P>0.05). Vascular diseases were the most frequently detected by CE in patients of each age group, which in underage group ( age <18 years), young and middle-aged group ( age 18 - 59 years) and elderly group ( age ≥60 years ) were 44.5%, 22.7% and 34.3%, and in the second place were nonspecific inflammation (22.2%) in underage group, Crohn's disease (17.6%) in young and middle-aged group and tumors (22.9%) in elderly group, respectively. The detected diseases in patients for obscure gastrointestinal bleeding mainly included vascular diseases (43.0%), tumors (14.8%), non-steroidal anti-inflammatory drug-associated gastrointestinal mucosal disease (6.3%), Crohn's disease (6.3%), diverticulum (7.0%), acute gastric mucosal lesion (3.1%), and nonspecific inflammation (7.0%), and in patients for unexplained abdominal pain mainly included functional gastrointestinal disorders (27.5%), Crohn's disease (19.6%), nonspecific inflammation (15.7%), intestinal tuberculosis (9.8%), tumors (9.8%), irritable bowel syndrome (7.8%) and vascular diseases (2.0%). Conclusion: CE examination has higher detection rates for small bowel diseases, with applicability to wide population groups and high safety. The domestic and foreign imported CE examination systems have similar diagnostic value.

Abstract:Gastric cancer is one of the most common malignant tumors encountered in clinical practice, which seriously threatens human life and health. Studies have demonstrated that the occurrence of gastric cancer is associated with bacterial and virus infections, and epigenetic changes, especially changes in DNA methylation, play important roles in the progression of gastric cancer. Furthermore, DNA methylation detection has wide prospects for application in early diagnosis, prognosis assessment and treatment of gastric cancer. Hence, the authors address the relationship between DNA methylation and gastric cancer and the clinical applications.

Abstract:Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract, and most of them are caused by the gene mutations of KIT or platelet-derived growth factor receptor α (PDGFRA). However, approximately 10% to 15% of the GISTs without KIT or PDGFRA gene mutations are called wild type GISTs, which include succinate dehydrogenase-deficient GISTs, BRAF mutant GISTs and neurofibromatosis 1-related GISTs. Researches on GISTs-associated genes can provide new ideas for the diagnosis and treatment of GISTs. The authors address the research progress of genes associated with the occurrence, development, diagnosis, treatment and prognosis of GISTs.