Short-term outcomes of a multicentre randomized clinical trial comparing laparoscopic pylorus-preserving gastrectomy with laparoscopic distal gastrectomy for gastric cancer (the KLASS-04 trial).

BACKGROUND: There remain concerns about the safety and functional benefit of laparoscopic pylorus-preserving gastrectomy (LPPG) compared with laparoscopic distal gastrectomy (LDG). This study evaluated short-term outcomes of a randomized clinical trial (RCT) comparing LPPG with LDG for gastric cancer. METHODS: The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-04 trial was an investigator-initiated, open-label, parallel-assigned, superiority, multicentre RCT in Korea. Patients with cT1N0M0 cancer located in the middle third of the stomach at least 5 cm from the pylorus were randomized to undergo LPPG or LDG. Participants, care givers and those assessing the outcomes were not blinded to group assignment. Outcomes were 30-day postoperative morbidity rate and death at 90 days. RESULTS: Some 256 patients from nine institutions were randomized (LPPG 129 patients, LDG 127 patients) between July 2015 and July 2017 and outcomes for 253 patients were analysed. Postoperative complications within 30 days were seen in 19.3 and 15.5 per cent in the LPPG and LDG groups respectively (P = 0·419). Postoperative pyloric stenosis was observed in nine (7.2 per cent) and two (1·5 per cent) patients in the LPPG and LDG groups (P = 0·026) respectively. In multivariable analysis higher BMI was a risk factor for postoperative complications (odds ratio 1·17, 95 per cent c.i. 1·04 to 1·32; P = 0·011). Death at 90 days was zero in both groups. CONCLUSION: Postoperative complications and mortality was comparable in patients undergoing LPPG and LDG. Registration number: NCT02595086 (http://www.clinicaltrials.gov).

Indocyanine green fluorescence lymphography during gastrectomy after initial endoscopic submucosal dissection for early gastric cancer.

BACKGROUND: Indocyanine green (ICG) fluorescence lymphography can be used to visualize the lymphatic drainage of gastric cancer. Few studies have been performed to identify lymphatic drainage patterns after endoscopic submucosal dissection (ESD). ESD results in changes to lymphatics owing to fibrosis of the submucosal layer. This study aimed to evaluate the efficacy of ICG fluorescence lymphography for visualization of lymphatic drainage after ESD, and to assess its clinical application in additional gastrectomy after ESD for early gastric cancer. METHODS: All patients who underwent gastrectomy after ESD between 2014 and 2017 in a single centre were reviewed. ICG was injected endoscopically into the submucosal layer around the ESD scar the day before surgery. At the time of surgery, lymph nodes (LNs) were visualized and lymphadenectomy was performed with near-infrared imaging. Ex vivo, all LNs were examined for the presence of fluorescence. Number of LNs resected and number of tumour-positive LNs were compared between patients who underwent near-infrared imaging and those who had conventional lymphadenectomy without intraoperative imaging. RESULTS: Some 290 patients underwent gastrectomy after ESD, 98 with fluorescence lymphography-guided lymphadenectomy and 192 with conventional lymphadenectomy. Fluorescence lymphography visualized lymphatic drainage in all patients, without complications related to ICG injection or near-infrared imaging. Fluorescence lymphography visualized all stations containing metastatic LNs. The sensitivity for detecting LN metastasis in fluorescent stations was 100 per cent (9 of 9 stations), and the negative predictive value was 100 per cent (209 of 209). One patient with LN metastasis had one non-fluorescent metastatic LN within a fluorescent station. CONCLUSION: Fluorescence lymphography successfully visualized all draining LNs after ESD, with high sensitivity and negative predictive value for detecting LN metastasis. Fluorescence lymphography-guided lymphadenectomy could be an alternative to systematic lymphadenectomy during additional surgery after ESD.

ANTECEDENTES: La linfografía de fluorescencia con verde de indocianina (indocyanine green, ICG) visualiza el drenaje linfático del cáncer gástrico. Se han realizado pocos estudios para identificar los patrones de drenaje linfático tras una disección submucosa endoscópica (endoscopic submucosal dissection, ESD). La ESD introduce cambios de los linfáticos debido a la fibrosis de la capa submucosa. El objetivo de este estudio era valorar la eficacia de la linfografía con ICG para visualizar el drenaje linfático tras ESD y evaluar su aplicación clínica en la gastrectomía adicional después de ESD por carcinoma precoz gástrico (early gastric cancer, EGC). MÉTODOS: Se revisaron todos los pacientes sometidos a gastrectomía tras ESD entre 2014 y 2017 en un único centro. El ICG se inyectó por vía endoscópica en la capa submucosa alrededor de la cicatriz tras ESD el día antes de la cirugía. En el momento de la cirugía, se visualizaron los ganglios linfáticos (lymph nodes, LNs) y se realizó la linfadenectomía siguiendo las imágenes de infrarrojo. Ex vivo, todos los LNs se examinaron para detectar la presencia de fluorescencia. Se compararon el número de LNs resecados y el número de LNs afectados por el tumor entre pacientes sometidos a imágenes de infrarrojo y pacientes a los que se les realizó una linfadenectomía convencional sin imágenes intraoperatorias. RESULTADOS: Un total de 290 pacientes fueron sometidos a gastrectomía tras ESD (98 con linfadenectomía por linfografía con ICG y 192 con linfadenectomía convencional). La linfografía con ICG visualizó el drenaje linfático en todos los pacientes, sin complicaciones relacionadas con la inyección de ICG o con las imágenes de infrarrojo. La linfografía con ICG permitió visualizar todas las estaciones ganglionares en las que había LNs metastásicos. La sensibilidad para detectar los LN con metástasis en las estaciones con fluorescencia fue del 100% (9 de 9 estaciones), y el valor predictivo negativo (negative predictive value, NPV) del 100% (209 de 209 estaciones). Un paciente con metástasis en LN tenía un ganglio metastásico sin fluorescencia en el seno de una estación con fluorescencia. CONCLUSIÓN: La linfografía con fluorescencia visualiza satisfactoriamente todos los LNs que drenan después de ESD, con una elevada sensibilidad y NPV para detectar metástasis en LN. La linfadenectomía guiada por fluorescencia podría ser una alternativa a la linfadenectomía convencional durante la cirugía adicional después de ESD.

Laparoscopic sentinel node navigation surgery versus laparoscopic gastrectomy with lymph node dissection for early gastric cancer: short-term outcomes of a multicentre randomized controlled trial (SENORITA).

BACKGROUND: Sentinel node navigation surgery reduces the extent of gastric and lymph node dissection, and may improve quality of life. The benefit and harm of laparoscopic sentinel node navigation surgery (LSNNS) for early gastric cancer is unknown. The SENORITA (SEntinel Node ORIented Tailored Approach) trial investigated the pathological and surgical outcomes of LSNNS compared with laparoscopic standard gastrectomy (LSG) with lymph node dissection. METHODS: The SENORITA trial was an investigator-initiated, open-label, parallel-assigned, non-inferiority, multicentre RCT conducted in Korea. The primary endpoint was 3-year disease-free survival. The secondary endpoints, morbidity and mortality within 30 days of surgery, are reported in the present study. RESULTS: A total of 580 patients were randomized to LSG (292) or LSNNS (288). Surgery was undertaken in 527 patients (LSG 269, LSNNS 258). LSNNS could be performed according to the protocol in 245 of 258 patients, and a sentinel node basin was detected in 237 (96·7 per cent) Stomach-preserving surgery was carried out in 210 of 258 patients (81·4 per cent). Postoperative complications occurred in 51 patients in the LSG group (19·0 per cent) and 40 (15·5 per cent) in the LSNNS group (P = 0·294). Complications with a Clavien-Dindo grade of III or higher occurred in 16 (5·9 per cent) and 13 (5·0 per cent) patients in the LSG and LSNNS groups respectively (P = 0·647). CONCLUSION: The rate and severity of complications following LSNNS for early gastric cancer are comparable to those after LSG with lymph node dissection. Registration number: NCT01804998 ( http://www.clinicaltrials.gov).

ANTECEDENTES: La cirugía de navegación del ganglio centinela (sentinel node navigation surgery, SNNS) reduce la extensión de la resección gástrica y ganglionar, y puede mejorar la calidad de vida. Se desconoce el beneficio y el daño de la cirugía de navegación del ganglio centinela por vía laparoscópica (laparoscopic sentinel node navigation surgery, LSNNS) para el cáncer gástrico precoz. El ensayo clínico SENORITA investigó los resultados patológicos y quirúrgicos de LSNNS en comparación con la gastrectomía laparoscópica estándar (laparoscopic gastrectomy, LSG) con disección ganglionar (lymph node dissection, LND). MÉTODOS: El ensayo SENORITA fue un ensayo multicéntrico aleatorizado y controlado, iniciado por investigadores, abierto, con asignación a grupos paralelos y de no inferioridad llevado a cabo en Corea. El resultado primario fue la supervivencia libre de enfermedad a los 3 años. En el presente estudio, se describen los resultados secundarios correspondientes a morbilidad y mortalidad a los 30 días del postoperatorio. RESULTADOS: Un total de 580 pacientes fueron aleatorizados a LG (n = 292) o LSNNS (n = 288). La cirugía se realizó en 527 pacientes (LG 269, LSNNS 258). LSNNS pudo ser realizada de acuerdo con el protocolo en 245 de 258 pacientes y en 237 de 245 pacientes (96,7%) se detectó un ganglio centinela. La cirugía con preservación del estómago se realizó en 210 de 258 pacientes (81,4%). Las complicaciones postoperatorias se presentaron en 51 pacientes del grupo LSG (19,0%) y en 40 pacientes (15,5%) del grupo LSNNS (P = 0,294). Las complicaciones grado III o mayor de Clavien-Dindo se detectaron en 16 (5,9%) y 13 pacientes (5,0%) de los grupos LSG y LSNNS, respectivamente (P = 0,647). CONCLUSIÓN: El porcentaje y la gravedad de las complicaciones tras LSNNS para cancer gástrico precoz son comparables a la LSG con LND.

Locoregional relapse after gastrectomy with D2 lymphadenectomy for gastric cancer.

BACKGROUND: Risk for and site of locoregional relapse have not been well studied in patients undergoing gastrectomy with D2 lymphadenectomy for gastric cancer. METHODS: Patients who had undergone gastrectomy with D2 lymphadenectomy for gastric cancer between 2004 and 2007 were identified from an institutional database. The locoregional relapse rate was estimated by competing risk analysis, and risk groups were derived according to locoregional relapse risk using recursive partitioning analysis (RPA). The locations of nodal relapses were evaluated according to Japanese Classification of Gastric Carcinoma criteria. RESULTS: Some 2618 patients were included. With a median follow-up of 78·0 (range 28·5-122·6) months, relapse was diagnosed in 471 of 2618 patients (18·0 per cent). The cumulative incidence of locoregional relapse at 5 years was 8·5 (95 per cent c.i. 7·4 to 9·6) per cent. The 5-year locoregional recurrence rates for high-risk (N3), intermediate-risk (N1-2) and low-risk (N0) groups were 32·4, 12·3 and 1·7 per cent respectively (P < 0·001). Among patients with regional relapse, 90·4 per cent had involvement outside the D2 dissected area, and the most commonly involved site was station 16b1. This pattern was maintained in the RPA risk groups (P = 0·329). CONCLUSION: Locoregional relapse at 5 years after gastrectomy with D2 lymphadenectomy was 8·5 per cent, and was most often seen outside the D2 dissected area.

Minimally invasive surgery for serosa-positive gastric cancer (pT4a) in patients with preoperative diagnosis of cancer without serosal invasion.

BACKGROUND: Although surgeons normally use minimally invasive surgery (MIS) for patients with early gastric cancer, in Korea and Japan the procedure is also indicated for serosa-negative tumors. Serosal invasion is regarded to be a potential risk factor for peritoneal dissemination as a result of the effect of pneumoperitoneum and tumor manipulation during the operation. We compared operative outcomes between MIS and conventional open surgery for serosa-involved advanced gastric cancer patients who had a preoperative diagnosis of cancer without serosal invasion. METHODS: A total of 61 patients (39 patients treated by MIS and 22 by open surgery) treated between 2003 and 2009 who were first diagnosed preoperatively as serosa negative on the basis of computed tomography, endoscopy, and endoscopic ultrasound but then diagnosed as serosa positive upon final pathology were studied. We retrospectively compared recurrence and survival between the two treatment groups. RESULTS: Clinicopathologic characteristics, clinical stage, extent of surgery, and short-term operative outcome did not differ between the groups. 5-year overall survival (73.5 vs. 67.5 %, p = 0.518, respectively) and disease-free survival (67.8 vs. 54.2 %, p = 0.296, respectively) were comparable between the MIS and open surgery groups. There were recurrences in 12 patients in the MIS group and 11 patients in the open surgery group, with a median follow-up period of 64 months. Recurrence patterns did not differ between the groups; moreover, MIS did not increase peritoneal recurrences compared to open surgery (42.0 vs. 54.5 %, p = 0.537, respectively). In multivariate analyses, the type of surgery was not an independent prognostic factor. CONCLUSIONS: Similar survival and recurrence patterns were observed in advanced gastric cancer patients preoperatively diagnosed as serosa negative who were treated either by MIS or open surgery. MIS may be safely applied in patients with serosa-positive tumors.

Major early complications following open, laparoscopic and robotic gastrectomy.

BACKGROUND: Laparoscopic and robotic gastrectomy have been adopted rapidly despite lack of evidence concerning technical safety and controversy regarding additional benefits. This study aimed to compare clinically relevant complications after open, laparoscopic and robotic gastrectomy. METHODS: This was a retrospective analysis of prospectively collected data on surgical complications in patients undergoing gastrectomy with curative intent for histologically proven adenocarcinoma between 2005 and 2010 at the Department of Surgery, Yonsei University College of Medicine in Seoul, Korea. Complications were categorized into wound infection, bleeding, anastomotic leak, obstruction, fluid collection and other. RESULTS: In a total of 5839 patients (4542 open, 861 laparoscopic and 436 robotic gastrectomies), overall complication, reoperation and mortality rates were 10·5, 1·0 and 0·4 per cent respectively. There were no significant differences between the three groups. Ileus (P = 0·001) and intra-abdominal fluid collections (P = 0·013) were commoner after conventional open surgery. However, tumour stage was higher and more complex resections were performed in the open group. Anastomotic leak, the leading cause of death, occurred more often after a minimally invasive approach (P = 0·017). CONCLUSION: Laparoscopic and robotic gastrectomy had overall complication and mortality rates similar to those of open surgery, but anastomotic leaks were more common with the minimally invasive techniques.

Relevance of lymph node metastasis along the superior mesenteric vein in gastric cancer.

BACKGROUND: The purpose of this study was to evaluate the prognostic value of lymph node metastasis along the superior mesenteric vein (station 14v) to determine the need for 14v dissection in gastric cancer surgery. METHODS: A total of 1104 patients with gastric cancer who underwent gastrectomy including 14v dissection were enrolled. Patients were categorized into two groups: those with and those without 14v lymph node involvement by metastasis. RESULTS: Of the total study population, 73 patients (6·6 per cent) had 14v-positive gastric cancer. These patients were more likely to have advanced tumour (T), node (N) and distant metastatic (M) status, and histologically undifferentiated gastric cancers. The 3- and 5-year survival rates of patients with 14v-positive disease were 24 and 9 per cent respectively. Survival in this group was similar to that of patients who had gastric cancer with distant metastasis (M1). Multivariable analysis demonstrated that 14v status was a significant prognostic factor for gastric cancer (hazard ratio 2·13; P < 0·001). After histologically complete (R0) resection, the overall survival of 14v-positive patients with any stage of cancer was significantly worse than that for 14v-negative patients with stage IV cancer (P = 0·006). CONCLUSION: 14v status is an independent prognostic factor for gastric cancer, with 14v-positive gastric cancer having a poor prognosis, similar to that of M1 disease. The exclusion of 14v in regional lymph node dissection should be considered.

Factors influencing operation time of laparoscopy-assisted distal subtotal gastrectomy: analysis of consecutive 100 initial cases.

AIMS: There is little information on patient selection criteria for laparoscopy-assisted distal gastrectomy (LADG) that would facilitate a successful initial experience for a surgeon new to the procedure. This study aimed to establish patient selection criteria that will allow increased proficiency and shorter operation times for the LADG procedure. METHOD: One hundred LADG with lymphadenectomy and no other combined procedures were consecutively performed by one surgeon. These 100 consecutive LADG procedures were analyzed retrospectively from a prospectively designed computer database. Uni- and multivariate analyses were performed to identify factors influencing operation time. RESULTS: According to univariate analysis, operation time was influenced by sex, BMI, surgical experience, and tumor location, whereas multivariate analysis indicated that operation time was significantly influenced only by BMI and surgical experience. The same analyses of only the first 50 cases showed that sex, BMI, surgical experience, and tumor location were independently associated with operation time. As BMI increased, so did operation time, whereas operation time decreased with increasing surgical experience. CONCLUSION: This study suggests that surgeons who have limited experience with this advanced procedure may shorten operation time by considering patient and tumor characteristics in their early attempts at LADG. With a shortened operation time, surgeon with limited experience may become proficient to LADG rapidly.

Integration of radiotherapy and chemotherapy for abdominal lymph node recurrence in gastric cancer.

PURPOSE: Abdominal lymph node (ALN) recurrence in gastric cancer (GC) is rare and usually unresectable. We investigated the effects of integration of radiotherapy (RT) and chemotherapy against ALN recurrence in GC. METHODS: We retrospectively categorized GC patients with ALN recurrence treated between 2005 and 2013 into two groups: those treated with integration of RT and chemotherapy (RCT) and those who received systemic chemotherapy only (CT). The median follow-up period after ALN recurrence for all patients was 20 months. RESULTS: Of 53 patients, 31 and 22 were in the RCT and CT groups, respectively. Isolated distant failure (DF; 35.5%) without local progression (LP) was the dominant pattern of failure (POF) in the RCT group (median DF-free period, 26 months). LP followed by DF (31.8%) was the dominant POF in the CT group; LP (median LP-free period, 8 months) occurred 10 months earlier than DF (median DF-free period, 18 months). RCT patients had significantly longer median progression-free survival (PFS) compared to CT patients (25 vs. 8 months; P = 0.021). On multivariate analysis, treatment (CT vs. RCT) was an independent prognostic factor for PFS (hazard ratio 2.085; 95% confidence interval 1.073-4.050; P = 0.013). CONCLUSIONS: Integration of RT and chemotherapy achieved long-term local control and prolonged PFS in GC patients with ALN recurrence. Local RT is feasible for treating isolated ALN recurrences.

Correlation between lymph node count and survival and a reappraisal of lymph node ratio as a predictor of survival in gastric cancer: A multi-institutional cohort study.

PURPOSE: The purpose of this study is to evaluate the correlation between lymph node count (LNC) and survival and to evaluate whether lymph node ratio (LNR) which is related to LNC is a better predictor of survival for gastric cancer than the N category of UICC/AJCC through a multi-institutional cohort study. METHODS: The study cohort included 3284 patients from eight institutions. Lower and upper quartiles of LNC were used for comparisons. The cut-off values (0, 0.06, 0.27, and 0.49) for the LNR categories were based on Classification and Regression Trees techniques. Akaike information criteria (AIC) for Cox regression models was used to evaluate goodness of fit between competing predictor variables (LNR vs. N category). RESULTS: The 5-year disease-specific survival (DSS) rates of lower and upper quartiles of LNC were 82.2% and 84.8%. In the subgroup analysis of pN category, the upper quartile of LNC showed better survival than the lower quartile in pN2, pN3a, and pN3b subgroups. Regarding LNR, 5-year DSS of LNR 0, 0-0.06, 0.06-0.27, 0.27-0.49, and >0.49 was 95.3%, 88.7%, 70.6%, 42.7%, and 17.2% respectively. Multivariate analysis showed that pT, pN, LNR, residual tumor status, distant metastasis, and tumor differentiation significantly affected survival. The analysis also confirmed superiority of LNR compared with N category in the AIC analysis. CONCLUSION: Higher LNC correlated with better survival in patients with pN2, pN3a, and pN3b gastric cancer. Our data indicate that LNR is a better predictor of survival than N category of UICC/AJCC.

Who may benefit from robotic gastrectomy?: A subgroup analysis of multicenter prospective comparative study data on robotic versus laparoscopic gastrectomy.

AIMS: Robotic gastrectomy for gastric cancer has been proven to be a feasible and safe minimally invasive procedure. However, our previous multicenter prospective study indicated that robotic gastrectomy is not superior to laparoscopic gastrectomy. This study aimed to identify which subgroups of patients would benefit from robotic gastrectomy rather than from conventional laparoscopic gastrectomy. METHODS: A prospective multicenter comparative study comparing laparoscopic and robotic gastrectomy was previously conducted. We divided the patients into subgroups according to obesity, type of gastrectomy performed, and extent of lymph node dissection. Surgical outcomes were compared between the robotic and laparoscopic groups in each subgroup. RESULTS: A total of 434 patients were enrolled into the robotic (n = 223) and laparoscopic (n = 211) surgery groups. According to obesity and gastrectomy type, there was no difference in the estimated blood loss (EBL), number of retrieved lymph nodes, complication rate, open conversion rate, and the length of hospital stay between the robotic and laparoscopic groups. According to the extent of lymph node dissection, the robotic group showed a significantly lower EBL than did the laparoscopic group after D2 dissection (P = 0.021), while there was no difference in EBL in patients that did not undergo D2 dissection (P = 0.365). CONCLUSION: Patients with gastric cancer undergoing D2 lymph node dissection can benefit from less blood loss when a robotic surgery system is used.

Intraoperative tumor localization using laparoscopic ultrasonography in laparoscopic-assisted gastrectomy.

BACKGROUND: During laparoscopic-assisted gastrectomy, it is impossible to identify early gastric cancer (EGC) lesions; therefore, a precise localization technique is needed. In this study, we used laparoscopic ultrasonography (LUS) after endoscopic clipping as a method of localizing EGC and evaluated the effectiveness of this method. METHODS: A prospective study of 17 patients who had undergone laparoscopic-assisted gastrectomy was performed. Three endoscopic clips were applied just proximal to the tumor during the preoperative endoscopy. The applied clips were detected from the serosal side of the stomach using LUS. The serosal surface of the lesion was marked with dye. RESULTS: In all patients, endoscopic clips were applied proximal to the lesion without complications, and the applied clips were confirmed by plain abdominal radiography. The clips were successfully detected by LUS in all patients. In the resected specimen, the serosal surface, marked with dye, was always just above the clips in the anterior wall or on the anterior wall opposite the clips applied in the posterior wall. The mean detection time was 4.7 min (range, 2-8). With this procedure, two patients underwent total gastrectomy and 15 patients underwent distal subtotal gastrectomy with gastroduodenostomy or gastrojejunostomy. Histological examination confirmed that the resection margins were tumor free in all patients. There was no operative morbidity related to the LUS procedure. CONCLUSIONS: Using LUS to detect endoscopic clips is an easy, safe, and accurate method to localize EGC lesions in laparoscopic-assisted gastrectomy.

Clinicopathologic characteristics of mucinous gastric adenocarcinoma.

There has been considerable controversy over the prognosis of mucinous gastric adenocarcinoma (MGC). In this study we analyzed the clinicopathologic differences between MGC and non-mucinous gastric carcinoma (NMGC). In addition, the relationship between mucin content and other clinicopathologic variables, including prognosis in MGC, was also investigated. We reviewed 2118 patients with pathologically-confirmed gastric cancer who underwent gastrectomy at the Department of Surgery, Yonsei University College of Medicine, during the period between Jan. 1987 and Dec. 1993. Among them, 130 patients had gastric carcinoma with extracellular mucin (MGC) and 1988 patients had gastric carcinoma without extracellular mucin (NMGC). We placed the MGC patients into two groups according to mucin content: mucin content involving over 50% of the tumor (dominant type, n = 94) and mucin content involving less than 50% of the tumor area (partial type, n = 36). The results were as follows: MGC was more common in males than NMGC. The size of the tumor in MGC (mean 5.3 cm) was larger than that of NMGC (mean 4.4 cm). The patients with MGC had a higher incidence of Borrmann type IV (MGC: 16.1%, NMGC: 9.9%), more frequent serosal invasion (MGC: 75.4%, NMGC: 48.6%), lymph-node metastasis (MGC: 75.4%, NMGC: 50.7%), and peritoneal metastasis (MGC: 10.0%, NMGC: 3.5%) than patients with NMGC. The patients with MGC were more advanced in stage at the time of diagnosis and had a worse overall 10-year survival rate (44.9%) than patients with NMGC (54.7%). However, the 10-year survival rate according to the stage of MGC was similar to that of NMGC. There were no significant differences between the mucin content and other pathologic variables, including prognosis, i.e. similar biologic behavior between dominant type MGC and partial type MGC. In conclusion, we suggest that MGC was more frequently diagnosed in advanced stage than NMGC with a poorer prognosis and that it is reasonable to consider the carcinoma with mucin content involving more than 30% of the tumor area as MGC.

Rapid and safe learning of robotic gastrectomy for gastric cancer: multidimensional analysis in a comparison with laparoscopic gastrectomy.

BACKGROUND: The learning curve of robotic gastrectomy has not yet been evaluated in comparison with the laparoscopic approach. We compared the learning curves of robotic gastrectomy and laparoscopic gastrectomy based on operation time and surgical success. METHODS: We analyzed 172 robotic and 481 laparoscopic distal gastrectomies performed by single surgeon from May 2003 to April 2009. The operation time was analyzed using a moving average and non-linear regression analysis. Surgical success was evaluated by a cumulative sum plot with a target failure rate of 10%. Surgical failure was defined as laparoscopic or open conversion, insufficient lymph node harvest for staging, resection margin involvement, postoperative morbidity, and mortality. RESULTS: Moving average and non-linear regression analyses indicated stable state for operation time at 95 and 121 cases in robotic gastrectomy, and 270 and 262 cases in laparoscopic gastrectomy, respectively. The cumulative sum plot identified no cut-off point for surgical success in robotic gastrectomy and 80 cases in laparoscopic gastrectomy. Excluding the initial 148 laparoscopic gastrectomies that were performed before the first robotic gastrectomy, the two groups showed similar number of cases to reach steady state in operation time, and showed no cut-off point in analysis of surgical success. CONCLUSIONS: The experience of laparoscopic surgery could affect the learning process of robotic gastrectomy. An experienced laparoscopic surgeon requires fewer cases of robotic gastrectomy to reach steady state. Moreover, the surgical outcomes of robotic gastrectomy were satisfactory.

Risk factors for double primary malignancies and their clinical implications in patients with sporadic gastric cancer.

AIMS: We carried out a large scale study to identify the risk factors for double primary malignancy (DPM) development in gastric cancer patients and to evaluate the clinical implications for these patients. METHODS: A total of 2593 patients who underwent gastrectomy for primary gastric cancer from January 2005 to November 2010 were reviewed with regard to DPM. We compared the clinicopathological characteristics, risk factors for developing DPM, and prognosis between the DPM+ group and the DPM- group. RESULTS: Of the 2593 patients, 152 (5.9%) were diagnosed with DPM. The most common accompanying malignancies were colorectal, lung and thyroid. Multivariate analysis indicated that age (p = 0.016) and MSI status (p = 0.002) were associated with a higher frequency of DPM. 30.3% of patients were diagnosed with DPM within 1 year around perioperative period and 53.3% of patients had DPM detected during 5 years of post-operative follow up periods. Although there was no significant difference in overall survival between the DPM+ and DPM- group, DPM+ patients had a worse prognosis than DPM- patients in stage I gastric cancer. CONCLUSIONS: Gastric cancer patients over the age of 60 or with a MSI-high status had an increased risk for developing DPM. Further, in stage I gastric cancer, the presence of DPM was associated with a worse prognosis. Therefore, careful pre- and postoperative surveillance is especially important in these patients.

Impact of pretreatment thrombocytosis on blood-borne metastasis and prognosis of gastric cancer.

BACKGROUND: Thrombocytosis has been associated with malignancies and poor prognostic implications in cancer patients. In the present study the prognostic significance of pretreatment platelet (PLT) level was assessed with regard to recurrence and survival in patients with primary gastric adenocarcinoma. METHODS: The authors reviewed the prospective data of 1593 gastric cancer patients who received curative gastrectomy with extended lymphadenectomy. The correlations of PLT level with recurrence and overall survival were evaluated by both univariate and multivariate analyses. RESULTS: Thrombocytosis (≥ 40 × 10(4)/ µL), present in 6.4% of the patients prior to curative surgery, was more frequently associated with advanced T and N classification, larger tumor size, anemia, and leukocytosis (p < 0.05). In patients with pretreatment thrombocytosis compared to those without it, five-year survival rate was worse (56.9% vs. 65.5%; p = 0.043), and recurrence rate was higher mainly due to the frequent hematogenous spread (51.0% vs. 34.5%; p < 0.001). Furthermore, risk of blood-borne metastasis was almost three-fold higher in patients with pretreatment thrombocytosis (Odds ratio 2.83 [95% CI 1.67-4.77], p < 0.001). CONCLUSIONS: Pretreatment thrombocytosis correlated significantly with poor prognosis and can be used as an independent predictor of recurrence by blood-borne metastasis in gastric cancer.

Lymph node dissection around the splenic artery and hilum in advanced middle third gastric carcinoma.

AIM: To evaluate the clinicopathological factors influencing lymph node metastasis around the splenic artery and hilum and the effect of spleen-preserved lymphadenectomy in advanced middle third gastric carcinoma. METHODS: We retrospectively studied 131 patients with advanced middle third gastric carcinoma who had received D2 lymphadenectomy and lymph node dissection around the splenic artery and hilum, from 2000 to 2004. Of these patients, 62 simultaneously underwent splenectomy and 69 underwent spleen-preserved lymphadenectomy. RESULTS: The incidences of Nos. 10 and 11 lymph node metastases were 21% and 15%, respectively, in advanced middle third gastric carcinoma. A tumor size larger than 5 cm, metastases of Nos. 1 and 7-9 lymph node were independent risk factors for metastasis of No. 10 and/or No. 11 lymph node. The spleen-preserved group had a slightly better survival rate and a relatively lower rate of postoperative complications than the splenectomy group. No. 10 and/or No. 11 lymph node metastasis was an independent prognostic factor, while splenectomy was not. CONCLUSIONS: It is necessary to remove the lymph nodes around the splenic artery and hilum to achieve radical resection in advanced middle third gastric carcinoma patients with risk factors. Our results demonstrate that spleen-preserved lymphadenectomy is a good option for those patients.

Impact of splenectomy for lymph node dissection on long-term surgical outcome in gastric cancer.

BACKGROUND: In the treatment of gastric cancer, splenectomy is performed for effective lymph node dissection around the splenic artery and splenic hilum. The purpose of this study was to clarify the long-term outcome of splenectomy in the treatment of gastric cancer. METHODS: The effect of splenectomy on recurrence and prognosis was examined in a retrospective analysis of 665 patients who had undergone curative total gastrectomy for gastric carcinoma from 1987 to 1996. The risk factors associated with recurrence and prognosis were investigated by univariate and multivariate analysis. RESULTS: The splenectomy group showed more advanced lesions and a higher recurrence rate than the spleen-preserved group. However, after adjusting for the TNM (tumor, node, metastasis) stage, there was no significant difference in recurrence rate and pattern between the two groups. Logistic regression analysis revealed that gross type, serosal invasion, and nodal metastasis were independent risk factors for recurrence while splenectomy was not. When comparing patients with the same TNM (tumor, node, metastasis) stages, no significant difference in the 5-year survival rates was apparent. Multivariate analysis demonstrated that age, serosal invasion, and nodal metastasis were independent prognostic factors whereas splenectomy was not. CONCLUSIONS: These data suggest that splenectomy for lymph node dissection in gastric cancer is not effective regarding long-term patient prognosis.