Histological transformation to signet-ring cell carcinoma in a patient with clinically aggressive poorly differentiated adenocarcinoma of the ascending colon after response to chemotherapy plus cetuximab: a case report.

BACKGROUND: Alteration of chemosensitivity or tumor aggressiveness in response to chemotherapy has been reported, and liquid biopsy assessment during chemotherapy for colorectal cancers has confirmed the acquisition of mutations in various oncogenes. However, the occurrence of histological transformation seems to be extremely rare in colorectal cancers, and the few existing case reports of this transformation are from lung cancer and breast cancer. In this report, we describe the histological transformation of clinically aggressive scirrhous-type poorly differentiated adenocarcinoma of the ascending colon to signet-ring cell carcinoma in almost all recurrent tumors that were confirmed by autopsy after response to chemotherapy plus cetuximab. CASE PRESENTATION: A 59-year-old woman visited our hospital with whole abdominal pain and body weight loss and was diagnosed with scirrhous-type poorly differentiated adenocarcinoma of the ascending colon with aggressive lymph node metastases. The intrinsic chemosensitivity of the tumors was evident upon initiation of mFOLFOX6 plus cetuximab therapy, and right hemicolectomy was performed, and the tumor obviously remained in the peripancreatic area, paraaortic region, or other retroperitoneal areas. The ascending colon tumors mainly consisted of poorly differentiated adenocarcinoma and were not associated with signet-ring cell components except for minute clusters in a few lymphatic emboli in the main tumor. Chemotherapy was continued, and metastases were eliminated at 8 months after the operation; this response was maintained for an additional 4 months. Discontinuation of chemotherapy plus cetuximab resulted in immediate tumor recurrence and rapid expansion, and the patient died of the recurrent tumor 1 year and 2 months after the operation. Autopsy specimens revealed that almost all of the recurrent tumors exhibited transformation and consisted of signet-ring cell histology. CONCLUSION: This case might suggest that various oncogene mutations or epigenetic changes resulting from chemotherapy, especially regimens that include cetuximab, contribute to the transformation of non-signet-ring cell colorectal carcinoma to signet-ring cell carcinoma histology and can promote the aggressive clinical progression characteristic of signet-ring cell carcinoma.

Grading of Atrophic Gastritis is Useful for Risk Stratification in Endoscopic Screening for Gastric Cancer.

OBJECTIVES: In order to screen for gastric cancer effectively, its interval should be set according to the risk. This study aimed to determine whether risk stratification is possible using the data obtained from medical examination or endoscopic findings. METHODS: First, subjects who underwent both cancer screening and medical examination from 2009 to 2015 and underwent cancer screening once more by 2016 were studied. Data such as the lipid profile and history of smoking obtained during the medical examination, and the grade of atrophy and presence of peptic ulcers were studied using multivariate analysis. Next, subjects who underwent cancer screening twice or more between 2009 and 2015 with or without medical examinations were studied to analyze any correlation between the grade of atrophy and cancer occurrence using univariate analysis. In both studies, the status of Helicobacter pylori (HP) infection was determined. RESULTS: In the multivariate analysis, 9378 subjects were included. Aging, advanced atrophy, presence of ulcers, and uric acid levels were identified as risk factors. Among subjects who underwent successful HP eradication therapy, advanced atrophy and aging were observed to be crucial risk factors. In the univariate analysis, there were 12,941 subjects. Gastric cancer occurred more frequently in the more severe atrophy group (P < 0.001). The annual rate of cancer occurrence in the most severe atrophy group was 0.31%, which was approximately thrice as that in the less atrophy group. CONCLUSIONS: Risk stratification was possible based on endoscopic examination alone. The interval should be set depending on each case.

A randomized controlled trial of postoperative intravenous acetaminophen plus thoracic epidural analgesia vs. thoracic epidural analgesia alone after gastrectomy for gastric cancer.

BACKGROUND: Acetaminophen is used in multimodal therapy for postoperative pain management. However, the additional effects of acetaminophen in combination with thoracic epidural analgesia (TEA) are not well understood. This prospective, multicenter randomized study was conducted to evaluate the efficacy of routine intravenous (i.v.) acetaminophen in combination with TEA for the management of postoperative pain in gastric cancer surgery. METHODS: A total of 120 patients who underwent distal gastrectomy were randomly assigned in a 1:1 ratio to receive i.v. acetaminophen every 6 h and TEA during the first 3 postoperative days (acetaminophen group) or TEA alone (control group). The primary endpoint was the sum of TEA rescue doses during the first 2 postoperative days. RESULTS: Final analysis included 58 patients in the acetaminophen group and 56 patients in the control group. The median number of TEA rescue doses was significantly lower in the acetaminophen group compared with the control group (3.0 vs. 8.0, p = 0.013). The median area under the curve (AUC) of the pain scores at coughing was significantly less in the acetaminophen group compared with the control group (285 vs. 342, p = 0.046) without an increase in postoperative complications. TEA rescue doses and pain score AUCs were significantly reduced by acetaminophen in patients who underwent open gastrectomy (p = 0.037 and 0.045), whereas there was no significant difference between patients who underwent laparoscopic gastrectomy in the two groups. CONCLUSIONS: In gastric cancer surgery patients, routine i.v. acetaminophen in combination with TEA provides superior postoperative pain management compared with TEA alone.

A rapidly growing, large, mature retroperitoneal teratoma in an adult male patient.

A 40-year-old man complaining of abdominal distention was referred to our hospital. Computed tomography of the abdomen demonstrated a very large abdominal mass with fat and calcification. The size of the mass rapidly increased from 30cm to 40cm over two weeks. The tumor was removed and diagnosed by pathological examination to be a retroperitoneal mature cystic teratoma that contained a 40-cm long, mature intestinal tract-like cyst, together with bone marrow and fat. The rapid growth of the tumor may have been caused by an increased secretion in the cyst.

Exploratory phase II trial in a multicenter setting to evaluate the clinical value of a chemosensitivity test in patients with gastric cancer (JACCRO-GC 04, Kubota memorial trial).

BACKGROUND: Although postoperative adjuvant chemotherapy with S-1, an oral fluoropyrimidine, has become a standard of care for gastric cancer in Japan, nonresponders may suffer from the cost and adverse reactions without clinical benefit. This multicenter exploratory phase II trial was conducted to see whether a chemosensitivity test, the collagen gel droplet embedded culture drug sensitivity test (CD-DST), can adequately select patients for chemotherapy. METHODS: The CD-DST using four different concentrations of 5-fluorouracil was conducted with resected specimens from preregistered patients who underwent gastrectomy with D2 or more extensive lymphadenectomy. Patients who were histopathologically confirmed to have stage II or greater disease without distant metastasis were eligible for final enrollment. All patients underwent protocol-specified adjuvant chemotherapy with S-1. Three-year relapse-free survival was compared between patients determined as sensitive by the CD-DST (responders) and those deemed insensitive (nonresponders). Appropriate cutoff values for in vitro growth inhibition were defined when the hazard ratio for relapse in responders and the log-rank P values were at their minimum. RESULTS: Of the 311 patients enrolled, 14 were ineligible and 27 failed to start the protocol treatment. The CD-DST failed in 64 other patients, and survival analyses were conducted with the remaining 206 patients (39 stage II disease, 155 stage III disease, and 12 stage IV disease). The outcome of patients who were determined to be responders was significantly superior to that of nonresponders regardless of the 5-fluorouracil concentrations, although no differences in clinicopathologic characteristics were observed between the two groups, except for age. CONCLUSIONS: The CD-DST identified those who benefit from adjuvant chemotherapy. It deserves further evaluation in the setting of a prospective randomized trial. ClinicalTrials.gov identifier: NCT00287755.

Evaluation of the efficacy of palonosetron for prevention of chemotherapy-induced nausea and vomiting in patients with gastric cancer treated with S-1 plus cisplatin.

PURPOSE: The purpose of our study was to evaluate the efficacy of a new combination antiemetic therapy consisting of palonosetron, aprepitant, and dexamethasone in gastric cancer patients undergoing chemotherapy with S-1 plus cisplatin. METHODS: This prospective, multi-institutional observational study assessed patient-reported nausea, vomiting, use of rescue therapy, change of dietary intake, and Functional Living Index-Emesis (FLIE) questionnaire results. The percentages of patients showing complete response (CR; no emesis and non-use of any rescue antiemetics) and complete protection (CP; no significant nausea and non-use of any rescue antiemetics), change of dietary intake, and impact of chemotherapy-induced nausea and vomiting on daily life during the overall (0-120 h after cisplatin administration), acute (0-24 h), and delayed (24-120 h) phases were examined. These findings were compared with our previous study, which used granisetron, aprepitant, and dexamethasone, to assess the relative effectiveness of palonosetron versus granisetron in combination antiemetic therapy. RESULTS: Of the 72 included patients, 66 (91.6 %), 70 (97.2 %), and 50 (69.1 %) achieved CR, and 48 (66.7 %), 61 (84.7 %) and 49 (68.1 %) achieved CP during in the overall, acute, and delayed phases of cisplatin administration, respectively. Approximately half of the patients had some degree of anorexia. FLIE results indicated that 78.6 % of patients maintained their quality of life. Palonosetron was not superior to granisetron in combination antiemetic therapy. CONCLUSIONS: Three-drug combination antiemetic therapy with palonosetron, aprepitant, and dexamethasone was tolerable in gastric cancer patients undergoing treatment with S-1 plus cisplatin. The predominance of palonosetron to granisetron was not demonstrated in this study.

Surgical resection of brain and adrenal gland metastases from gastric cancer: a case report and literature review.

The prognosis of recurrent gastric cancer is generally poor, and aggressive surgical treatment is rarely performed. Herein, we present the case of a patient who underwent resection of cerebellar and adrenal gland metastases from gastric cancer. The patient was treated for gastric cancer with distal gastrectomy at 23 years and for remnant gastric cancer with completion gastrectomy at 48 years. At 59 years old, she experienced vertigo and nausea and was diagnosed with cerebellar and left adrenal gland tumours. First, the cerebellar tumours were resected and diagnosed as metastases of gastric cancer. After 1 month, the adrenal gland tumour was resected and diagnosed as metastatic. She underwent whole-brain radiotherapy and subsequent chemotherapy with S-1. One year after the surgery, the patient died of meningitis carcinomatosa. There are few reports on long-term survival after the resection of brain metastases. Herein, we report our experience along with a review of the literature.

Jejunal gastrointestinal stromal tumor that developed in a patient with neurofibromatosis type 1: a case report.

BACKGROUND: Neurofibromatosis type 1 (NF1) is known to be associated with the frequent occurrence of unique gastrointestinal stromal tumors (GISTs), preferably occurring in the small intestine, with no mutations in the c-kit proto-oncogene or platelet-derived growth factor receptor-alpha (PDGFRA), with a high tendency for multifocal development, indolent nature, with low proliferation activity and favorable prognosis. CASE PRESENTATION: A woman in her forties visited her local doctor complaining of menstrual pain; a large mass was detected in her lower abdomen, and she was referred to our hospital. The patient had hundreds of skin warts and café au lait spots. The patient's mother had been diagnosed with type 1 neurofibromatosis. The patient met the diagnostic criteria for NF1 and was diagnosed with NF1. Ultrasonography showed a large heterogeneous cystic mass with various echo patterns, solid compartments and multiple septations. Magnetic resonance imaging showed a multilocular cystic mass with liquid content exhibiting various intensities, including that of blood. A small round solid mass was also observed close to the cystic tumor. Contrast-enhanced computed tomography showed that the round solid mass showed strong enhancement in the early phase, unlike the cystic tumor component. Open laparotomy revealed a multicystic exophytic tumor measuring 11.5 cm originating from the jejunal wall, 20 cm distal to the duodenojejunal flexure. A solid tumor measuring 2.1 cm was also found on the anal side of the large tumor. We resected the short segment of the jejunum, including the two lesions. Microscopic findings revealed that the cystic and solid tumors consisted of spindle-shaped tumor cells showing little atypia with a fascicular or bundle arrangement. Nuclear mitosis was scarce. Immunostaining of the tumor cells showed positive staining for KIT and DOG1 and negative staining for S100 and desmin. The NF1 patient was diagnosed with multiple GISTs accompanied by intratumoral hemorrhagic denaturation arising from the jejunum. The TNM staging was pT4N0M0, stage IIIA. CONCLUSION: We report a case of GISTs associated with NF1 that showed a jejunal origin, multifocal development and few mitotic figures. The recurrence risk, survival prognosis and need for adjuvant chemotherapy, particularly in cases where the initial GIST exhibits a very indolent pathology in NF1-related GISTs, remain to be elucidated.

Endocrine carcinoma of the stomach: clinicopathological analysis of 27 surgically treated cases in a single institute.

BACKGROUND: Gastric endocrine carcinoma (EC) is an uncommon tumor of the stomach and the clinical features are not well known. Additionally, the classification and staging systems of this tumor are not yet unified worldwide. In this study, we reviewed 27 patients with gastric EC to evaluate the clinicopathological characteristics of this tumor. METHODS: We retrospectively reviewed 27 patients with gastric EC among 6466 patients who had undergone gastrectomy between 1986 and 2008 at our institute. Clinicopathological features including immunohistochemistry of Ki-67 were investigated to evaluate the malignant potential of the tumor. Furthermore, survivals were compared between the 7th edition of the International Union Against Cancer (UICC)-TNM (7th TNM) classification for gastric cancer (GC) and the new TNM classification for foregut neuroendocrine tumors (NET). RESULTS: The median survival of the patients was 19.0 months. The 5-year survival rate was 100% in pathological stage (pStage) I, 40% in pStage II, 38% in pStage III, and 11% in pStage IV according to the 7th TNM classification for GC. Survivals by stage showed great difference between the 7th TNM classification for GC and the new TNM classification for foregut NET, but each system correlated with survival. The Ki-67 labeling index was more than 20% in most of the patients. Univariate analysis revealed that maximum tumor diameter, tumor depth, lymph node metastasis, lymphatic invasion, pStage, and curability had significant correlations with survival. CONCLUSION: Early detection and curative operations are essential for improving the prognosis of gastric EC. However, some adjuvant chemotherapies are required for advanced-stage tumors. Classification and staging systems may need to be unified worldwide for further analysis.

Long-term outcome and survival with laparoscopy-assisted pylorus-preserving gastrectomy for early gastric cancer.

BACKGROUND: Laparoscopically assisted pylorus-preserving gastrectomy (LAPPG) is introduced as a function-preserving operation with minimal invasion for early gastric cancer (EGC). This study aimed to investigate the long-term outcome and survival with LAPPG. METHODS: From January 2005 to July 2008, 188 patients with EGC underwent LAPPG. The surgical and long-term outcomes and survival were assessed retrospectively. RESULTS: The accuracy of the preoperative EGC diagnosis was 92.6%. The median follow-up period was 38 months (range, 2-63 months). Two patients experienced gallstones, and three patients experienced a second primary EGC. One patient with T3N0 gastric cancer died of peritoneal metastasis, and four patients died of other causes. The overall 3-year survival rate was 97.8%, and the disease-specific 3-year survival rate was 99.3%. CONCLUSIONS: The LAPPG procedure is safe in terms of satisfactory long-term outcome and survival for patients with EGC in the middle third of the stomach.

Outcome of surgical treatment for patients with locoregional recurrence of gastric cancer.

PURPOSE: Locoregional recurrent gastric cancer is commonly treated by systemic chemotherapy. The effectiveness of surgical treatment, in terms of complete tumor resection, is unknown. METHODS: We reviewed the case histories of 36 patients with locoregional recurrent gastric cancer, selected for surgical treatment by careful preoperative assessment. Patient characteristics and survival data were collected and analyzed. Prognostic factors were also assessed by univariate analysis using the log-rank test. RESULTS: Among 36 patients with recurrent gastric tumors, including 18 patients with local recurrences and 18 patients with single-regional lymph node recurrences, the average time to recurrence after initial surgery was 26.4 ± 2.8 months. Complete resection was possible in 29 patients (80.6%), with incomplete resection in the remaining seven patients (19.4%). Various types of surgery were used for tumor recurrence; 23 patients (63.9%) underwent procedures to resect the tumor and the affected organs. The median survival time (median ± standard error) was 23.0 ± 2.8 months, and overall 1-, 3-, and 5-year survival rates were 73.0%, 36.7%, and 9.8%, respectively. Complete resectability of the tumor was the only significant prognostic factor identified. CONCLUSIONS: Although there was no control group in the present study with similarly limited tumor recurrence and treated solely with modern systemic chemotherapy, such a study population would be too small to conduct a randomized study in. For those patients for whom surgery is indicated by multidisciplinary assessment, surgical resection can be applied for recurrent lesions if complete resection can be accomplished with low perioperative risk for the extended surgery.

Is preservation of the celiac branch of the vagal nerve effective in preventing stasis following pylorus-preserving gastrectomy?

BACKGROUND/AIMS: Although pylorus-preserving gastrectomy (PPG) is performed as a function preserving surgery, patients sometimes suffer from postoperative stasis of the gastric contents after the procedure. Preservation of blood flow and both celiac and pyloric branches of the vagal nerve may decrease the incidence of the stasis. METHODOLOGY: Patients who underwent PPG at the Cancer Institute Hospital between April 2005 and December 2007 were included in the study. Early surgical results and the incidence of stasis were investigated and compared between patients in whom the celiac branch had been preserved (PPG-CBP group) and those in whom it had not (PPG-nCBP group). RESULTS: Patients in the PPG-nCBP group had a higher body mass index than patients in the PPG-CBP group (23.9 vs. 22.3 kg/m2; p=0.004), as well as a longer operation time (249.3 vs. 227.0 min; p=0.010). There was no significant difference in the incidence of stasis between the groups (13% vs. 8%; p=0.523). CONCLUSIONS: There was no correlation between preservation of the celiac branch and the incidence of stasis in the first 30 days after PPG. A large randomized control trial investigating both short- and long-term outcomes after PPG is required to elucidate the primary cause of postoperative stasis.

Incidence and prognostic value of lymph node metastasis on c-Kit-positive gastrointestinal stromal tumors of the stomach.

BACKGROUND/AIMS: Surgical R0 resection is a mainstay of treatment for gastrointestinal stromal tumor (GIST) of the stomach. The incidence of lymph node metastasis (LNM) has been reported as extremely low. However, the actual incidence of LNM still remains unclear due to the limited number of patients who underwent systemic lymph node dissection. METHODOLOGY: Fifty-seven patients who underwent gastrectomy with systemic lymphadenectomy for c-Kit-positive GIST of the stomach at the Cancer Institute Hospital between 1970 and 2000 were included. The clinicopathological characteristics of the patients were used to clarify the incidence and prognostic value of LNM in patients with GIST of the stomach. RESULTS: R0 resection was achieved in 52/57 patients. The 5-year survival rate of patients following R0 resection was 68.6%. LNM was observed in 5/57 (8.8%) patients. All 5 patients died within 5 years after surgery even though 3 had undergone curative surgery. CONCLUSIONS: In patients with GIST of the stomach, the incidence of LNM following systemic lymphadenectomy is low. The prognosis of patients with LNM was poor; thus it should be regarded as an advanced disease.

Can superextended lymph node dissection be justified for gastric cancer with pathologically positive para-aortic lymph nodes?

BACKGROUND: The prognosis of patients with gastric cancer and para-aortic lymph node (PALN) metastasis is poor. Recent Japanese randomized trials concluded that prophylactic PALN dissection is not effective for curable advanced gastric cancer. However, the value of curative resection in patients with pathologically positive PALN is not determined yet. METHODS: We retrospectively identified 178 patients with pathologically positive PALN who underwent curative resection at the Cancer Institute Hospital from 1980 to 2004. Patient characteristics were analyzed and independent prognostic factors for death were identified by Cox proportional hazard model. RESULTS: Partial gastrectomy was the most frequently performed procedure (142 of 178). Postoperative morbidity and mortality rates were 30 and 2%, respectively, with a 5-year survival rate of 13.0%. Multivariate analysis revealed the total number of positive nodes (hazard ratio, 1.804; 95% confidence interval, 1.221-2.665) and macroscopic type (hazard ratio, 1.697; 95% confidence interval, 1.138-2.530) as independent prognostic factors, while age, sex, histology, pathological tumor depth, and degree of PALN dissection were not statistically significant. The 5-year survival rate increased to 28.6% in patients with < or =15 positive nodes and macroscopic type other than type 4. CONCLUSIONS: Prophylactic PALN dissection can not be justified in curable advanced gastric cancer. However, R0 resection including PALN retrieval might be beneficial in patients with pathologically positive PALN, providing patients are carefully selected and operations are performed safely.

Better prognosis of T2 gastric cancer with preoperative diagnosis of early gastric cancer.

BACKGROUND: Gastrectomy with D2 lymph node dissection is the standard treatment for locally advanced gastric cancer in Japan. However, in patients with a preoperative diagnosis of early gastric cancer, gastrectomy with limited lymph node dissection is generally selected as a treatment option, despite a pathological diagnosis of advanced gastric cancer. The aim of the present study was to clarify the clinicopathological characteristics and feasibility of limited lymph node dissection in patients with clinically early, but pathologically advanced, gastric cancer. MATERIALS AND METHODS: Clinicopathological characteristics, including the incidence and susceptible sites for lymph node metastasis, were investigated in 1528 patients with a final diagnosis of T2 gastric cancer treated at the Cancer Institute Hospital. For these patients, the results were compared between two groups including 266 patients preoperatively diagnosed as early T1 gastric cancer (EpT2) and 1262 patients preoperative diagnosed as locally advanced gastric cancer (ApT2). RESULTS: The pathological stage was lower (P < .001), and the 5-year survival rate was better (91.0% vs. 73.1%, P < .001) for the EpT2 group compared with the ApT2 group. Moreover, the N stage was smaller in the EpT2 group than in the ApT2 group, and the extension of lymph node metastasis was limited in 261 out of 266 patients (98%). CONCLUSION: Patients with EpT2 gastric cancer had a better 5-year survival rate than the patients in the ApT2 group. Gastrectomy with limited lymph node dissection could be indicated for patients with EpT2 gastric cancer unless intraoperative finding indicated obvious lymph node metastasis.

Better 5-year survival rate following curative gastrectomy in overweight patients.

BACKGROUND: Westernization of lifestyle and diet has resulted in an increase in overweight patients in Japan. Although the adverse effects of higher body mass index (BMI) on early surgical outcomes are known, the relationship between BMI and long-term outcome is unclear. MATERIALS AND METHODS: Clinicopathological characteristics and 5-year survival rate of overweight (BMI >or= 25 kg/m2; H-BMI; n = 1126) and nonoverweight (BMI < 25 kg/m2; N-BMI; n = 6799) patients who underwent gastrectomy with curative intent at the Cancer Institute Hospital between 1970 and 2004 were compared. RESULTS: Patients in the H-BMI group tended to have earlier-stage disease. The 5-year survival rate was significantly better in the H-BMI than N-BMI group (81.5% vs 74.1%, respectively; P < .001). Postoperative mortality was 1% in both groups (P = .482), whereas postoperative morbidity was 22% and 19% in the H-BMI and N-BMI groups, respectively (P = .007). Multivariate analysis indicated overweight, age, gender, surgical procedure, histology, operation year, pT, and pN as independent prognostic factors. Subset analyses of pT and pN stages revealed overweight as an independent prognostic factor in patients with pT1 and pN0. CONCLUSION: The 5-year survival rate following curative gastrectomy is better in overweight than nonoverweight Japanese patients, especially for early-stage gastric cancer. Further studies are needed to determine whether these results apply to other countries where morbidity and mortality for gastric cancer are higher than in Asian countries.

Therapeutic value of lymph node dissection in advanced gastric cancer with macroscopic duodenum invasion: is the posterior pancreatic head lymph node dissection beneficial?

BACKGROUND: In advanced gastric cancer (AGC) with duodenum invasion, the posterior pancreatic lymph nodes are susceptible to metastasis because of their proximity to the duodenum. The therapeutic value of lymph node dissection in this area for AGC with macroscopic duodenum invasion remains unclear. METHODS: Patients who had undergone curative gastrectomy for lower-third AGC from 1970 to 2004 at the Cancer Institute Hospital were recruited for this study. Clinicopathological data were collected retrospectively, and compared between cases of AGC with duodenum invasion (AGC-DI group) and AGC without duodenum invasion (AGC-nDI group). In the AGC-DI group, the therapeutic value of lymph node dissection was evaluated using a therapeutic index (multiplication of the frequency of metastasis to the station by the 5-year survival rate of patients with metastasis to that station). RESULTS: The AGC-DI group generally had tumors of higher pathological stage, which might account for the poorer 5-year survival rate compared with that of the AGC-nDI group (50.1% versus 68.5%; P = 0.0002). The incidence of lymph node metastasis was higher in the AGC-DI group than that in the AGC-nDI group, including nodes in the posterior pancreatic head (23.9% versus 7.0%, P < 0.0001). In the AGC-DI group, posterior pancreatic head lymph node dissection was of therapeutic value (4.19) equivalent to dissection of second-tier lymph nodes. CONCLUSIONS: The dissection of posterior pancreatic head lymph nodes might be effective in AGC with macroscopic duodenum invasion since this has therapeutic value equivalent to that of second-tier lymph node dissection and might improve patients' long-term outcomes.

Quality control and educational value of laparoscopy-assisted gastrectomy in a high-volume center.

BACKGROUND: Laparoscopy-assisted gastrectomy (LAG) is increasingly performed in Japan by a number of surgeons. As this is a relatively new technique, a training system is important, however there has been little discussion about an educational system for teaching trainees to perform LAG and the ideal training system has not yet been established. PATIENTS AND METHODS: Two hundred and sixty-three patients who underwent LAG at the Cancer Institute Hospital were included in this study. In all cases there was standardization of LAG (the way in which the surgical field was formed by the assistant and the way the operator dissected the lymph nodes was determined and all cases were performed using the same laparoscopic procedures) and a step-by-step training system was completed. Specialists performed the surgery in 213 patients (S group) while the remaining 50 patients had their surgery performed by trainees (T group). Early surgical outcomes were compared between specialists and trainees to clarify whether the standardization and our educational system are useful in maintaining the quality of LAG. RESULTS: T-group patients had significantly longer operation times than those of S-group (262.3 +/- 7.3 versus 233.3 +/- 3.7 min), however, the trainees reached the plateau of their learning curve earlier than previously reported. All other early surgical outcomes examined, including intraoperative blood loss (76.7 +/- 35.1 versus 64.9 +/- 7.7 ml), number of retrieved lymph nodes (33.4 +/- 1.4 versus 35.7 +/- 0.8), morbidity (8 versus 14%), and mortality (0% in both groups), were not significantly different between the two groups. CONCLUSION: The surgical results of T-group were almost equal to those of S-group, showing that our educational system is effective and surgical quality is maintained. Standardized laparoscopic procedures and sufficient intensive experience in the short term are requisites for effectively learning how to perform LAG.

Investigation of the lymphatic stream of the stomach in gastric cancer with solitary lymph node metastasis.

BACKGROUND: Understanding the lymphatic drainage route in gastric cancer is crucial for complete lymph node retrieval from sites susceptible to metastasis. However, the lymphatic stream of the stomach is complex and remains incompletely characterized. METHODS: Patients with small (<4 cm) serosa-negative gastric cancer with solitary lymph node metastasis treated at the Cancer Institute Hospital were included in this study. A total of 135 patients were classified according to the location of the solitary lymph node metastasis into the left gastric artery (LGA) group, the right gastroepiploic artery (RGEA) group, the right gastric artery (RGA) group, or the splenic artery (SA) group. The location of the primary tumors was investigated to aid the mapping of the lymphatic stream of the stomach. RESULTS: Lymphatic flow in LGA (65 patients) and in RGEA (57 patients) are main lymphatic drainage routes of the stomach. The lymphatic area overlapped in the lower third of the stomach in LGA and RGEA, and the lymphatic flow associated with gastric cancer located within this overlapped area can be multidirectional. Skip metastases were observed in 13 patients (10%), and all skip metastases were observed in the suprapancreatic area (station 7, 8a, 9, or 11p). CONCLUSIONS: The lymphatic stream of the stomach is complicated and multidirectional. Understanding and mapping the complex lymphatic streams of the stomach will allow surgeons to perform more effective lymph node dissection during gastric cancer surgery.