D2 Lymph Node Research Articles

A case-control study of using carbon nanoparticles to trace decision-making lymph nodes around inferior mesenteric artery in rectal cancer.

Accurate identification of lymph nodes localized around inferior mesenteric artery (IMA), with or without metastasis, is of crucial importance for surgeons when dissecting D2 or D3 lymph nodes in patients with rectal cancer (RC). The following study evaluates whether carbon nanoparticles can be used for detection of decision-making lymph nodes (DLNs) in station 253 lymph nodes found around IMA during RC surgery. A total of 66 patients with rectal adenocarcinomas were recruited between January 2014 and August 2017. Patients were divided into carbon nanoparticle (CN) group and control (CL) group; for the CN group, 1ml nanoparticles were endoscopically injected into submucosal layer of primary tumor 1day before surgery. DLNs were defined as black-dyed nodes in CN group or macroscopic lymph nodes in CL group localized along the IMA, proximal to the origin of the left colic artery. D3 lymph nodes were dissected using laparoscopic radical resection, and then examined using pathological approach. Intra-operative and post-operative data were compared between the two groups. In CN group, black-dyed DLNs were easily found under laparoscopy; the median number of DLNs was 3 (range 1-9). In CL group, the median number of DLNs was 0 (range 0-3). Consistency between intra-operative DLNs and post-operative station 253 nodes were confirmed by pathological examination. Significant higher number of DLNs in station 253 nodes (2.91 ± 2.47 vs 0.58 ± 0.75, p < 0.001), number of station 251 nodes (12.85 ± 8.99 vs 8.09 ± 5.85, p = 0.014), number of station 253 nodes (5.21 ± 5.26 vs 3.15 ± 2.32, p = 0.045), and the number of total lymph nodes (24.06 ± 13.20 vs 16.21 ± 9.09, p = 0.007) were found in the CN group compared to CL group. Carbon nanoparticles are useful for identifying DLNs in station 253 LNs around IMA in RC. It is not necessary to perform D3 lymph node dissection if there are no intra-operative DLNs metastases in RC.

Successful conversion surgery for unresectable gastric cancer with giant para-aortic lymph node metastasis after downsizing chemotherapy with S-1 and oxaliplatin: a case report

BackgroundAlthough patients with stage IV gastric cancer who respond well to systemic chemotherapy can be treated with gastrectomy, the prognosis of patients with unresectable gastric cancer with para-aortic lymph node metastasis is poor. We herein report a case of remnant gastric cancer with para-aortic lymph node metastasis that was treated with potentially curative conversion surgery after showing a complete response to chemotherapy with S-1 and oxaliplatin (SOX).Case presentationAn 81-year-old man was diagnosed with type 3 remnant gastric cancer with giant para-aortic lymph node metastasis, and he received SOX chemotherapy. After three courses of SOX chemotherapy, the primary tumor and para-aortic lymph node metastases markedly reduced in size, indicating a partial response. Because conversion surgery was possible, the patient underwent total remnant gastrectomy with D2 and para-aortic lymph node dissection. Histological examination revealed no residual cancer cells in the resected stomach and lymph nodes. The patient was diagnosed with a complete pathological response and was discharged on postoperative day 24. Currently, 1 year after surgery, the patient is alive and has not shown any tumor recurrence.ConclusionTo the best of our knowledge, this is the first case of advanced remnant gastric cancer with giant para-aortic lymph node metastasis that showed a pathological complete response and favorable outcome after SOX chemotherapy.

Central Lymph Node Metastasis in Gastric Cancer Is Predictive of Survival After Preoperative Therapy

BackgroundIt is unclear how preoperative therapy for gastric cancer affects the metastasis rate of lymph nodes (LNs) and whether the location of positive LNs affects survival after preoperative therapy. Therefore, we determined the association between positive central lymph nodes (CnLNs) and disease stage and overall survival (OS). MethodsWe reviewed a prospectively maintained database to identify patients who had undergone resection of gastric adenocarcinoma at our institution from 2005 to 2015. CnLNs were defined as common hepatic, celiac, and proximal splenic artery LNs (stations no. 8, 9, and 11p). The frequency of CnLN metastases and risk factors affecting OS were examined. ResultsWe identified 356 patients. Preoperative therapy was administered to 66% of patients. D2 LN dissection was performed in 80% of patients, and the median number of LNs examined was 25 (IQR, 18–34). In 243 patients (68%), CnLNs had undergone separate pathologic examination; the CnLN-positive rate was 9.1% (22 of 243; station no. 8, 4.5%; no. 9, 2.1%; and no. 11p, 4.8%). CnLN metastasis was associated with shorter 3-year OS in patients with pN2/3 disease (33 vs. 62%; p=0.004). Among patients who had undergone preoperative therapy, ypT3–4 stage (HR 2.44; p=0.01) and positive CnLNs (HR 5.44; p<0.001) were negatively associated with OS by multivariate analysis. ConclusionsCnLN metastases are uncommon in gastric cancer and have an adverse effect on OS in patients who have undergone preoperative therapy. Larger multi-institutional studies are needed to determine whether CnLN positivity requires a separate staging category after preoperative therapy.

Risk Factors for Peritoneal Recurrence in Stage II to III Colon Cancer.

BACKGROUND:Most previous reports to analyze risk factors for peritoneal recurrence in patients with colon cancer have been observational studies of a population-based cohort.OBJECTIVE:This study aimed to determine the risk factors for peritoneal recurrence in patients with stage II to III colon cancer who underwent curative resection.DESIGN:This was a pooled analysis using a combined database obtained from 3 large phase III randomized trials (N = 3714).SETTINGS:Individual patient data were collected from the Japanese Foundation for Multidisciplinary Treatment of Cancer clinical trials 7, 15, and 33, which evaluated the benefits of postoperative 5-fluorouracil–based adjuvant therapies in patients with locally advanced colorectal cancer.PATIENTS:We included patients who had stage II to III colon cancer and underwent curative resection with over D2 lymph node dissection.MAIN OUTCOME MEASURES:Main outcomes measured were risk factors for peritoneal recurrence without other organ metastasis after curative surgery.RESULTS:Peritoneal recurrence occurred in 2.3% (86/3714) of all patients undergoing curative resection. Mean duration from operation to peritoneal recurrence was 17.0 ± 10.3 months. Of these patients with peritoneal recurrence, 29 patients (34%) had recurrence in ≥1 other organ. Multivariate analysis showed that age (≥60 y: HR = 0.531; p = 0.0182), pathological T4 (HR = 3.802; p < 0.0001), lymph node involvement (HR = 3.491; p = 0.0002), and lymphadenectomy (D2: HR = 1.801; p = 0.0356) were independent predictors of peritoneal recurrence. The overall survival was lower in patients who developed peritoneal recurrence than in those with other recurrence (HR = 1.594; p = 0.002).LIMITATIONS:The regimens of adjuvant chemotherapy were limited to oral 5-fluorouracil.CONCLUSIONS:Our findings clarified the risk factors for peritoneal recurrence in patients who underwent curative resection for colon cancer. See Video at http://links.lww.com/DCR/A609.

Prognostic impact of splenic hilar lymph node metastasis in proximal gastric carcinoma: A retrospective analysis of 665 patients treated with D2 total gastrectomy.

11 Background: Standard D2 lymph node (LN) dissection for proximal gastric carcinoma includes removing splenic hilar LNs. However, patients with splenic hilar LN metastasis often show a poor prognosis even after curative surgery. This study aimed to investigate the prognostic impact of splenic hilar LN metastasis in proximal gastric carcinoma. Methods: We reviewed prospectively constructed data of 665 patients who underwent total gastrectomy with D2 LN dissection for proximal gastric carcinoma. Clinicopathological features and survivals were compared between patients with and without splenic hilar LN metastasis. The prognostic value of splenic hilar LN metastasis was examined using a multivariate Cox prognostic model. Results: Of 665 patients, 63 (9.5%) with stage III or IV disease had splenic hilar LN metastasis. Splenic hilar LN metastasis was associated with a larger tumor size, B4 gross type, undifferentiated histology, and lymphovascular invasion. The 5-year survival of patients with splenic hilar LN metastasis was significantly worse at each tumor stage (stage III = 45% vs. 66%, p = 0.044, stage IV = 12% vs. 32%, p = 0.017). The 5-year survival of patients with splenic hilar LN metastasis did not significantly differ from that of the distant metastasis group (26% vs. 31%, p = 0.484). Multivariate analysis revealed that splenic hilar LN metastasis is an independent poor prognostic factor when adjusting for tumor node metastasis stage and other prognostic factors. Conclusions: Patients with splenic hilar LN metastasis show a poor prognosis after surgery. More intensive adjuvant treatment and postoperative surveillance will be required for patients with splenic hilar LN metastasis.

Necessity of D2 lymph node dissection in older patients ≥ 80 years with gastric cancer

This study analyzed the effect of D2 lymph node (LN) dissection on complications and survival in older patients with gastric cancer. A total of 103 octogenarian patients who underwent curative gastrectomy for gastric cancer were divided into two groups (D2 and D1) according to the extent of LN dissection and analyzed retrospectively for complications and survival. No differences were observed in short-term postoperative outcomes, including complication rates, between the two groups. In a survival analysis, D2 LN dissection did not improve overall survival (OS) in any patient, including advanced cases. A Cox regression analysis revealed that the independent risk factors for OS were history of coronary artery disease (hazard ratio [HR], 11.095), postoperative short-term complications (HR, 9.939), and TNM stage (HR, 6.299). The extent of LN dissection was not an independent risk factor for OS, and D2 or more LN dissection (odds ratio, 10.89) increased the risk independently. D2 or more LN dissection did not improve survival, but rather increased the risk of complications. Thus, LN dissection should be performed sparingly in octogenarian patients with gastric cancer.

Left Gastric Artery Lymph Nodes Should Be Included in D1 Lymph Node Dissection in Gastric Cancer

BackgroundThe Japanese Classification of Gastric Carcinoma includes the left gastric artery (#7) lymph nodes (LNs) in the recommended extent of D1 LN dissection, but this recommendation has not been validated in western institutions. MethodsWe reviewed data from a prospectively maintained database of gastric cancer patients who underwent resection at our academic cancer center and had a separate pathologic assessment of #7 LN in 2005–2016. Risk factors for #7 LN metastases and overall survival were examined by uni- and multivariable analyses. ResultsWe identified 173 patients; 114 (66%) were treated with preoperative therapy, most commonly with chemoradiation therapy (47%, 81/173). We identified 22 patients (13%) who had #7 LN metastases, which accounted for 35% (22/63) of node-positive patients. No preoperative factors were associated with #7 LN metastases by univariable analyses. Patients with #7 metastases were not associated with shorter overall survival after adjustment by nodal stage (hazard ratio 1.49, 95% confidence interval 0.67–3.32; p = 0.33). ConclusionMetastasis to #7 LN station was common in gastric cancer, but the survival impact was not significant after adjustment by nodal stage. We conclude that #7 LNs should be routinely dissected in gastric cancer patients, and this station should be included within the extent of D1 LN dissection.

Impact of splenic hilar lymph node metastasis on prognosis in patients with advanced gastric cancer.

Background:Impact of splenic hilar LN dissection during total gastrectomy for proximal advanced gastric cancer is controversial. The objective of this study was to assess the impact on prognosis of splenic hilar lymph node(LN) metastasis compared to that of metastasis to other regional LN groups.Study DesignPatients who underwent total gastrectomy with D2 LN dissection from 2000 to 2010 were reviewed retrospectively. The clinicopathologic characteristics and long-term results of patients with splenic hilar LN metastasis were compared to those of patients with only metastasis to other extraperigastric LNs (stations #8a, #9, #11, or #12a). To investigate the survival benefit of performing splenic hilar LN dissection, the estimated therapeutic index for the procedure was calculated by multiplying the incidence of metastases in the hilar region by the survival rates for individuals with nodal involvement in that region.ResultsOf 602 patients, 87(14.5%) had hilar LN metastasis. The 5-year overall and relapse-free survival rates for patients with hilar LN metastasis were 24.1% and 12.1%, respectively. These rates were similar to those for patients with metastasis to other extraperigastric LNs (P > 0.05), with similar recurrence patterns. Overall survival in the hilar LN metastasis group was better than that for patients with distant metastasis(P < 0.05). The estimated therapeutic index of splenic hilar LN dissection was 3.5, which was similar to index values for LN dissection at other extraperigastric LNs.ConclusionsDissection of splenic hilar LNs during total gastrectomy for advanced gastric cancer allows for a prognosis similar to that achieved with dissection of extraperigastric LNs.

Laparoscopic segmental gastrectomy for early gastric cancer

To investigate the feasibility of segmental pylorus-reservation gastrectomy in patients with early gastric cancer. A retrospective cohort study on clinical data of 6 patients strictly met the criteria of early gastric cancer locating in the middle of the stomach undergoing laparoscopic segmental gastrectomy from January 2014 to April 2016 at Department of General Surgery, Peking Union Medical College Hospital was carried out. Preoperative clinical staging revealed T1N0M0 for all the cases. One case received endoscopic mucosa resection(EMR) first, and postoperative pathology showed moderate differentiated adenocarcinoma invading substratum of mucosa, so a complementary laparoscopic segmental gastrectomy was performed. Surgical procedure was laparoscopic segmental gastrectomy with D1 or D2 lymph node dissection. Vagus nerve was not reserved during lymph node dissection in lesser curvature side. Number of resected lymph node, postoperative complication and long-term gastric function were observed. Of 6 cases, 3 were male and 3 were female with age ranging from 55 to 59 years old. The distal resection margin was (4.6±0.5) cm away from pylorus. The average number of resected lymph node was 18.3±7.5 without metastasis. Follow-up time was 1 to 29 months for all the 6 cases and no relapse or metastasis was found during the follow-up. In 4 cases with follow-up beyond 1 year, 3 cases had slight distension in superior belly after meal and dyspepsia; another one case had vomiting nocturnal occasionally. Gastroscope examination one year after operation found food residue in all the cases. Images indicated the decrease of stomach size in all the cases. Two cases had esophagogastric reflux. All the patients had delayed gastric emptying symptoms after operations and were relieved within one year. It is technically feasible to perform laparoscopic segmental gastrectomy in patients with early gastric cancer. Whether vagus nerve should be reserved requires further investigation.

Application of lymph node labeling with carbon nanoparticles by preoperative endoscopic subserosal injection in laparoscopic radical gastrectomy

Objective: To evaluate the application value of carbon lymph node tracing technique by preoperative endoscopic subserosal injection in laparoscopic radical gastrectomy. Methods: From June 2013 to February 2015, seventy eight patients with gastric cancer were enrolled and randomly divided into trial group and control group. Subserosal injection of carbon nanoparticles around the tumor was performed by preoperative endoscopic subserosal injection one day before the operation in trial group, while the patients routinely underwent laparoscopic gastrectomy in control group. Results of harvested lymph nodes, postoperative complications were compared between the two groups. Carbon nanoparticle-related side effect was also evaluated. Results: The average number of harvested lymph node in trial group was significantly higher than that in control group (35.5±8.5 vs 29.5±6.5, P<0.05). The rate of overall black-dyed harvested lymph node was 74.7% (1 035/1 386) in trial group, the black-dyed lymph node rate in D1 lymph node was 80.1%, which was significantly higher than that in D2 lymph node (69.8%, χ2=19.38, P<0.01). When comparing the lymph node with and without black-dyed in trial group, the rate of metastasis lymph node was significantly higher in lymph node with black-dyed (17.3% vs 4.0%, χ2=38.67, P<0.01). There was no significant difference in postoperative complications rate between two group (trial group 10.2%; control group 12.8%, χ2=0.00, P>0.05), and no carbon nanoparticle-related side effect was observed. Conclusion: Given a higher harvested lymph node number and a similar rate of complications, preoperative endoscopic subserosal injection of carbon nanoparticles was safe and feasible.

Postoperative chemotherapy with S-1 plus oxaliplatin versus S-1 alone in locally advanced gastric cancer (RESCUE-GC study): a protocol for a phase III randomized controlled trial.

BackgroundThe ACTS-GC study had shown postoperative adjuvant therapy with S-1 improved survival of patients with locally advanced gastric cancer. Addition of oxaliplatin to S-1 is considered to be acceptable as one of the treatment options for gastric cancer patients after radical gastrectomy with D2 lymph node excision.MethodsWe have commenced a randomized phase III trial in December 2016 to evaluate S-1 plus oxaliplatin compared with S-1 alone in the adjuvant setting for locally advanced gastric cancer. A total of 564 patients will be accrued from 13 Chinese institutions in two years. The primary endpoint is 3-year relapse-free survival. The secondary endpoints are 5-year overall survival, proportion of patients who complete the postoperative chemotherapy and incidence of adverse events.Ethic and disseminationThe trial has been approved by the institutional review board of each participating institution and it was activated on December, 2016. The enrollment will be finished in December, 2018. Patient’s follow-up will be ended until December, 2023.Trial registrationClinicalTrials.gov, identifier: NCT02867839. Registered on August 4, 2016.

Does a Higher Cutoff Value of Lymph Node Retrieval Substantially Improve Survival in Patients With Advanced Gastric Cancer?-Time to Embrace a New Digit.

The present study assessed the impact of the retrieval of >25 lymph nodes (LNs) on the survival outcome of patients with advanced gastric cancer after curative-intent gastrectomy. A total of 5,386 patients who had undergone curative gastrectomy for gastric cancer from 1994 to 2011 were enrolled. The clinicopathological parameters and overall survival (OS) were analyzed according to the number of LNs examined (≤15, n = 916; 16-25, n = 1,458; and >25, n = 3,012). The percentage of patients with >25 LNs retrieved increased from 1994 to 2011. Patients in the LN >25 group were more likely to have undergone total gastrectomy and to have a larger tumor size, poorer tumor differentiation, and advanced T and N stages. Hospital mortality among the LN ≤15, LN 16-25, and LN >25 groups was 6.1%, 2.7%, and 1.7%, respectively (p < .0001). The LN >25 group consistently exhibited the most favorable OS, in particular, with stage II disease (p = .011) when OS was stratified according to tumor stage. Similarly, the LN >25 group had significantly better OS in all nodal stages (from N1 to N3b). The discrimination power of the lymph node ratio (LNR) for the LN ≤15, LN 16-25, and LN >25 groups was 483, 766, and 1,560, respectively. Multivariate analysis demonstrated that the LNR was the most important prognostic factor in the LN >25 group. Retrieving more than 25 lymph nodes during curative-intent gastrectomy substantially improved survival and survival stratification of advanced gastric cancer without compromising patient safety. The Oncologist 2017;22:97-106Implications for Practice: D2 lymph node (LN) dissection is currently the standard of surgical management of gastric cancer, which is rarely audited by a third party. The present study, one of the largest surgical series worldwide, has shown that the traditionally recognized retrieval of ≥16 LNs during curative-intent gastrectomy might not be adequate in regions in which locally advanced gastric cancers predominate. The presented data show that retrieval of >25 LNs, which more greatly mimics D2 dissection, improves long-term outcomes and survival stratification without compromising patient safety.

Short Term Outcomes of Laparoscopic versus Open Distal Gastrectomy with D2 Lymph Nodes Dissection for Gastric Cancer: A Prospective Study

Background: Laparoscopic distal gastrectomy (LDG) for gastric adenocarcinoma (GA) is gaining more acceptances worldwide. Its results are still controversial. This study aimed to assess short term outcomes of LDG and compare it to the standard open distal gastrectomy. Patients and Methods: 27 patients with GA of the distal 2/3 of the stomach were included and divided into 2 groups; Group A: 15 patients submitted to open distal gastrectomy with D2 lymph node (LN) dissection, and Group B: 12 patients submitted to LDG with D2 LN dissection. Results: The median age was 54 and 54.3 years in group A and B respectively. The median operative time was 118.7 and 210.2 minutes in group A and B respectively. The median safety margin was 6.52 and 5.7 cm in group A and B respectively while the median number of excised LN was 24.2 and 21.4 in group A and B respectively. One patient in group B had intraoperative bleeding that was controlled laparoscopically. No conversion to open surgery needed in group B. The median number of narcotic doses was 5.9 and 4.25 in group A and B respectively. The median length of hospital stay was 7.2 days in group A and 7.3 days in group B. Three patients in group A and 2 patients in group B had postoperative complications and all were treated successfully conservatively. Conclusion: LDG with D2 LN dissection is oncologically safe with short-term outcomes comparable to those of the open surgery. Gaining more surgeons’ experience is necessary to improve these results.

A Case of Advanced Gastric Cancer with Para-Aortic Lymph Node Metastasis from Co-Occurring Prostate Cancer.

An 84-year-old man was diagnosed with two synchronous adenocarcinomas, a Borrmann type IV advanced gastric adenocarcinoma in his antrum and a well-differentiated Borrmann type I carcinoma on the anterior wall of the higher body of his stomach. Pre-operatively, computed tomography of the abdomen revealed the presence of advanced gastric cancer with peri-gastric and para-aortic lymph node (LN) metastasis. He planned for palliative total gastrectomy owing to the risk of obstruction by the antral lesion. We performed a frozen biopsy of a para-aortic LN during surgery and found that the origin of the para-aortic LN metastasis was from undiagnosed prostate cancer. Thus, we performed radical total gastrectomy and D2 LN dissection. Post-operatively, his total prostate-specific antigen levels were high (227 ng/mL) and he was discharged 8 days after surgery without any complications.

The Prevalence of Overall and Initial Lymph Node Metastases in Clinical T1N0 Thoracic Esophageal Cancer: From the Results of JCOG0502, a Prospective Multicenter Study.

To evaluate the sites and frequencies of overall and initial lymph node (LN) metastases (LNMs) of clinical T1N0 esophageal cancer. The sites and frequencies of initial LNMs and sentinel LNs (SLNs) of esophageal cancer remain unclear. The Japan Clinical Oncology Group JCOG0502 trial was a 4-arm prospective study that compared esophagectomy with chemoradiotherapy for clinical T1N0 esophageal cancer in both randomized and patient-preference arms. The preoperative diagnostic accuracy was evaluated for patients assigned to the surgery arm. Patients who withdrew consent and who were not treated were excluded. All patients underwent esophagectomy with D2 or greater LN dissection. From the pathologic findings, sites and frequencies of LNMs and SLNs were assessed and the frequency of skip LNMs was calculated. In total, 211 patients underwent LNM and SLN analysis. Regarding N-factor accuracy, 57 (27.0%) of 211 clinical N0 cases had pathologic LNMs. The upper mediastinal and mediastinal/abdominal regions were frequent sites of LNMs in upper and lower thoracic cases, respectively. However, in middle thoracic cases, LNMs were observed in the neck, mediastinal, and abdominal regions, and pathologic SLN spread to all 3 fields. The frequency of skip LNMs was 36.7%. A clinical diagnosis of T1N0 is not sufficiently accurate, and therefore, it is unacceptable to omit LN dissection or minimize the prophylactic radiation field. SLNs, which are not location restricted, should be surveyed in all 3 fields.

Strategy of laparoscopic suprapancreatic lymph node dissection for advanced gastric cancer

The lymph nodes (LNs) that distribute along the celiac artery (CA) system in the suprapancreatic area include LNs around the root of the left gastric vessels (No. 7, No. 8a, No. 9 and No. 11p) and the right gastric vessels (No. 5 and No. 12a). Due to the high rate of LNs metastasis and the various vascular anatomies in this area, the suprapancreatic LN dissection is a crucial and demanding procedure for radical resection in the treatment of patients with advanced gastric cancer (AGC). Laparoscopic gastrectomy with D2 LN dissection has not yet been widely adopted for advanced stages because it is technically complicated. The initial segment of the splenic artery (SpA) approach is recommended as the ideal approach for laparoscopic suprapancreatic LN dissection in AGC.

Diffusion MRI on lymph node staging of gastric adenocarcinoma.

The purpose of this study was to evaluate the accuracy of diffusion weighted magnetic resonance imaging (MRI) in preoperative assessment of metastatic lymph nodes of gastric cancer. A total of 23 gastric cancer patients with a mean age of 59.4±10.9 years were analyzed. Lymph nodes were grouped as perigastric lesser curvature (Group Ia), perigastric greater curvature (Group Ib), D1+/D2 lymph nodes (Group II). Identification of histologically metastatic lymph nodes by diffusion weighted MRI was regarded as the main outcome. A total of 1,056 lymph nodes including 180 histologically proven metastatic lymph nodes were dissected. Although diffusion weighted MRI could identify the metastatic lymph nodes in 18 out of 23 patients (77.8%), only 69 of total 1,056 nodes (6.53%), either metastatic or non-metastatic, could be detected. There was no correlation between histopathology and diffusion weighted MRI with regard to lymph node groups (P>0.05 for all). Overall accuracy was calculated as 69.56, 65.21 and 52.17 for Groups II, Ib and Ia lymph nodes, respectively. Apparent diffusion coefficient (ADC) values could not be helpful to differentiate metastatic lymph nodes (P=0.673). Diffusion weighted MRI has low accuracy to detect or to differentiate metastatic and non-metastatic lymph nodes based on their ADC values in gastric cancer.

A phase II study of systemic chemotherapy with docetaxel, cisplatin, and S-1 (DCS) followed by gastrectomy with D2 plus para-aortic lymph node (PAN) dissection for gastric cancer with extensive lymph node metastasis (ELM): Japan Clinical Oncology Group Study JCOG1002.

116 Background: Gastric cancer with ELM is commonly regarded as unresectable with poor prognosis. We previously reported the safety and efficacy of cisplatin and S-1 (CS) followed by D2 gastrectomy with PAN dissection for this target (JCOG0405, Br J Surg 2014). Methods: Eligibility criteria included histologically proven gastric adenocarcinoma; bulky nodal involvement around major branched arteries to the stomach (Bulky N) and/or PAN metastases; cM0 (except PANs); negative lavage cytology; neither Borrmann type 4 nor large (8cm or more) type 3; PS 0 or 1. Patients received two or three cycles of induction chemotherapy of docetaxel (40mg/m2 day1), cisplatin (60mg/m2 day1), and S-1 (80mg/m2from day 1 to 14) every 4 weeks, and then underwent D2 gastrectomy with PAN dissection. After R0 resection, postoperative chemotherapy with S-1 was given for one year. The primary endpoint is response rate (RR) of NAC by central peer review. The planned sample size was 50 patients, provided 80% power under the hypothesis of primary endpoint as the expected RR of 80% and threshold RR of 65% with a one-sided alpha of 10%. Results: Between 07/2011 and 05/2013, 53 patients were enrolled and 1 patient was ineligible: 30 had Bulky N, 14 had PAN metastases, and 9 had both. 51of 52 patients (98.1%) completed a planned NAC. The clinical RR was 57.7% (30/52) (80%CI [47.9%-67.1%], one-sided p=0.89). The R0 resection rate was 84.6% (45/52). During DCS chemotherapy, grade 3/4 neutropenia occurred in 39.6% and grade 3/4 non-haematological adverse events in 20.8%. The incidence of grade 3/4 adverse events related to surgery was 30.6%. There was no treatment-related death. The pathological finding revealed minor response (residual tumor &lt;1/3) was achieved in 50.0% (26/52) and major response (residual tumor &lt;2/3) in 34.6% (18/52). The long-term survival is still under follow-up. Conclusions: Preoperative DCS revealed feasible but could not show sufficient efficacy. Preoperative CS is still being considered a standard treatment for this population. Clinical trial information: UMIN000006069.

Long-term survival results of laparoscopy-assisted distal gastrectomy with suprapancreatic nodal dissection for clinical stage I gastric cancer: A multicenter phase II trial (JCOG 0703).

113 Background: Laparoscopic gastrectomy has been a common tool for gastric cancer patients in eastern Asian countries. A large-scale prospective study with a sample size sufficient to investigate the benefit of laparoscopy-assisted distal gastrectomy (LADG) has never been reported. We conducted a multi-center phase II trial (JCOG0703) to evaluate the safety of LADG with nodal dissection for clinical stage I gastric cancer patients. A short-term outcome including postoperative complications of LADG as a result of this study was already reported and a following multi-center phase III trials (JCOG0912) to confirm the non-inferiority of LADG compared with open gastrectomy in terms of overall survival (OS) was already started. Long-term outcomes as the secondary endpoints of this study are reported here after 5-year follow up period. Methods: The subjects of this study comprised patients with clinical stage I gastric cancer that were able to undergo a distal gastrectomy. LADG with D1 plus suprapancreatic lymph node dissection was performed by credentialed gastric surgeons who experienced &gt;=30 LADG and &gt;=30 open gasterctomy. The primary endpoint was the proportion of patients who developed either anastomotic leakage or a pancreatic fistula. The secondary endpoints included surgical morbidity, short-term clinical outcome, OS, and relapse free survival (RFS). Results: Between November 2007 and September 2008, 176 eligible patients were enrolled. 140/23/9/4 patients had pStage IA/IB/II/IIIA disease respectively. No patients had recurrence. 3 patients died without recurrence. 5-year OS was 98.2% (95%CI, 94.7% to 99.4%). 5-year RFS was 98.2% (95%CI, 94.4% to 99.4%). Conclusions: The long-term outcome of LADG for Stage I gastric cancer patients seem comparable to those of open procedures. However, this result should be confirmed by a randomized control trial. We have just finished an accrual of 921 patients for a multi-center phase III trial (JCOG0912) to confirm the non-inferiority of LADG compared with open gastrectomy in terms of OS. Clinical trial information: UMIN000000874.

The prevalence of lymph node metastases in clinical T1N0 thoracic esophageal cancer from the results of JCOG0502.

10 Background: Recently, a limited operation to avoid needless lymph node (LN) dissection in clinical T1bN0 esophageal cancer (EC) is considered. However, how LN dissection or radiation field should be decided for such cases has not yet been clarified. The information about prevalence of LN metastases (LNMs) would be valuable when the radiation field and extent of LN dissection are considered in the treatment of T1bN0 EC. Methods: JCOG0502 is a randomized controlled trial including a patient preference arm comparing surgery alone to definitive chemoradiotherapy in clinical T1bN0 EC. By using baseline clinical and pathological data of JCOG0502, diagnosis accuracy of LNM was evaluated by comparing clinical and pathologic findings. Then, the sites of pathologic LNMs were determined and the initial sites and the prevalence of LNM were estimated. Results: Between Dec 2006 and Feb 2013, 213 patients (pts) enrolled to the surgery arm in JCOG0502. Pts with multiple lesions or without esophagectomy were excluded and remaining 186 pts were analyzed. Of the 186 pts of clinical T1bN0, 137 pts were diagnosed as LNM negative (73.7%: accuracy of diagnosis), however, 49 pts (26.3%) had pathologic LNMs. Pathologic LNMs were seen at 106recR, 106recL (all in mediastinal region) in upper thoracic (Ut) EC, 101R, 101L, 104R, 104L (in the neck region), 106recR, 106recL, 106tbL, 105, 107, 108, 109L, 110 (in the mediastinal region), 1,2,3,7, 11 (in the abdominal region) in middle thoracic (Mt) EC, and 105, 106recL, 110 (in the mediastinal region), 1, 2, 3, 7 (in the abdominal region) in lower thoracic (Lt) EC, respectively. Of the 49 pts who had pathologic LNMs, 32 pts (65%) were of pathologically N2 or more. Furthermore, 18 pts (37%) had skip LNM (LNM of N2, N3 or N4 without N1). The solitary pathologic LNM was observed in 25 pts: N1 (106recR, 106recL) in Ut, N1 (106recR, 106recL, 108), N2 (101R, 105, 110, 1, 3, 7), in Mt, N1(110, 1), N2 (106recL, 3, 7) in Lt, respectively. Conclusions: In the current status of clinical diagnosis, limited LN dissection or limited field of radiation are not recommended. In surgery, D2 LN dissection is necessary and three-field LN dissection is recommended especially in middle thoracic EC even for clinical T1bN0. Clinical trial information: UMIN000000551.