Optimal bowel resection margin in colon cancer surgery: prospective multicentre cohort study with lymph node and feeding artery mapping.

Background: There are no standardised criteria for the 'regional' pericolic node in colon cancer, which represents a major cause of the international uncertainty regarding the optimal bowel resection margin. This study aimed to determine 'regional' pericolic nodes based on prospective lymph node (LN) mapping. Methods: According to preplanned in vivo measurements of the bowel, the anatomical distributions of the feeding artery and LNs were determined in 2996 stages I-III colon cancer patients who underwent colectomy with resection margin >10 cm at 25 institutions in Japan. Findings: The mean number of retrieved pericolic nodes was 20.9 (standard deviation, 10.8) per patient. In all patients except seven (0.2%), the primary feeding artery was distributed within 10 cm of the primary tumour. The metastatic pericolic node most distant from the primary tumour was within 3 cm in 837 patients, 3-5 cm in 130 patients, 5-7 cm in 39 patients and 7-10 cm in 34 patients. Only four patients (0.1%) had pericolic lymphatic spread beyond 10 cm; all of whom had T3/4 tumours accompanying extensive mesenteric lymphatic spread. The location of metastatic pericolic node did not differ by the feeding artery's distribution. Postoperatively, none of the 2996 patients developed recurrence in the remaining pericolic nodes. Interpretation: The pericolic nodes designated as 'regional' were those located within 10 cm of the primary tumours, which should be fully considered when determining the bowel resection margin, even in the era of complete mesocolic excision. Funding: Japanese Society for Cancer of the Colon and Rectum.

A multicenter cohort study on mapping of lymph node metastasis for splenic flexural colon cancer.

Aim: There have been no reports of searching for metastases to lymph nodes along the accessory middle colic artery (aMCA). The aim of this study was to investigate the metastasis rate of the aMCA for splenic flexural colon cancer. Methods: Patients with histologically proven colon carcinoma located in the splenic flexure, clinically diagnosed as stage I-III were eligible for this study. Patients were retrospectively and prospectively enrolled. The primary endpoint was frequency of lymph node metastasis to the aMCA (station 222-acc and 223-acc). The secondary endpoint was the frequency of lymph node metastasis to the middle colic artery (MCA) (station 222-lt and 223) and left colic artery (LCA) (station 232 and 253). Results: Between January 2013 and February 2021, a total of 153 consecutive patients were enrolled. The location of the tumor was 58% in the transverse colon and 42% in the descending colon. Lymph node metastases were observed in 49 cases (32%). The presence of aMCA rate was 41.8% (64 cases). The metastasis rates of stations 221, 222-lt, and 223 were 20.0%, 1.6%, and 0%, and stations 231, 232, and 253 were 21.4%, 1.0%, and 0%, respectively. The metastasis rates of stations 222-acc and 223-acc were 6.3% (95% confidence interval: 1.7%-15.2%) and 3.7% (95% confidence interval: 0.1%-19%), respectively. Conclusions: This study identified the distribution of lymph node metastases from splenic flexural colon cancer. If the aMCA is present, this vessel should be targeted for dissection, taking into account the frequency of lymph node metastasis.

Optimizing nodal and staging classification in low rectal cancers with lateral node metastasis: multicentre retrospective cohort study.

BACKGROUND: Patients with lateral node metastasis in low rectal cancers have a poor prognosis. However, variability in patient survival in terms of lateral metastatic status has not been thoroughly investigated. This study was conducted to assess the prognostic value of lateral node involvement and to review nodal classification. METHODS: Patients with stage III low rectal cancers who underwent lateral node dissection were retrospectively reviewed. Two cohorts were set: the first one (1995-2006) was selected using a Japanese multi-institutional database and was used for development of a new nodal system, and the second (2007-2013) was collected from referral institutions for validation of findings. Variables correlated with poor prognosis were investigated. Next, a modified classification of lateral-positive nodal cancers was created. Finally, this new classification was compared with TNM and Japanese classification-based systems according to the Akaike information criterion (AIC) and concordance index (c-index). RESULTS: Overall, 742 and 508 patients were selected for cohorts 1 and 2, respectively. Based on the analyses on cohort 1, patients with two or more lateral metastatic nodes partially spreading into regions outside of internal iliac area exhibited poor prognosis; accordingly, a modified N classification was created, where TNM-N1 and N2a cancers with this feature were upgraded, respectively, to N2a and N2b. The modified N classification yielded the most favourable indices (AIC = 2661.08; c-index = 0.6477) compared with the TNM (AIC = 2662.36; c-index = 0.6457) and Japanese classification-based systems (AIC = 2684.06; c-index = 0.6302). All findings were confirmed by analysing cohort 2. CONCLUSION: A modified nodal system is proposed to account for the significance of lateral node metastasis.

The Conventional Technique Versus the No-touch Isolation Technique for Primary Tumor Resection in Patients With Colon Cancer (JCOG1006): A Multicenter, Open-label, Randomized, Phase III Trial.

OBJECTIVE: This phase III trial evaluated whether the no touch was superior to the conventional in patients with cT3/T4 colon cancer. BACKGROUND: No touch involves ligating blood vessels that feed the primary tumor to limit cancer cell spreading. However, previous studies did not confirm the efficacy of the no touch. METHODS: This open-label, randomized, phase III trial was conducted at 30 Japanese centers. The eligibility criteria were histologically proven colon cancer; clinical classification of T3-4, N0-2, andM0; and patients aged 20 to 80years. Patients were randomized (1:1) to undergo open surgery with conventional or the no touch. Patients with pathological stage III disease received adjuvant capecitabine chemotherapy. The primary endpoint was disease-free survival (DFS) according to the intention-to-treat principle. RESULTS: Between January 2011 and November 2015, 853 patients were randomized to the conventional group (427 patients) or the no touch group (426 patients). The 3-year DFS were 77.3% [95% confidence interval (CI) 73.1%-81.0%] and 76.2% (95% CI 71.9%-80.0%) in the conventional and no touch groups, respectively. The superiority of no touch was not confirmed: hazard ratio for DFS = 1.029 (95% CI 0.800- 1.324; 1-sided P = 0.59). Operative morbidity was observed in 31 of 427 conventional patients (7%) and 26 of 426 no touch patients (6%). All grade adverse events were similar between the conventional and no touch groups. No in-hospital mortality occurred in either group. CONCLUSION: The present study failed to confirm the superiority of the no touch.

Primary Tumor Resection Plus Chemotherapy Versus Chemotherapy Alone for Colorectal Cancer Patients With Asymptomatic, Synchronous Unresectable Metastases (JCOG1007; iPACS): A Randomized Clinical Trial.

PURPOSE: It remains controversial whether primary tumor resection (PTR) before chemotherapy improves survival in patients with colorectal cancer (CRC) with asymptomatic primary tumor and synchronous unresectable metastases. PATIENTS AND METHODS: This randomized phase III study investigated the superiority of PTR followed by chemotherapy versus chemotherapy alone in relation to overall survival (OS) in patients with unresectable stage IV asymptomatic CRC and three or fewer unresectable metastatic diseases confined to the liver, lungs, distant lymph nodes, or peritoneum. Chemotherapy regimens of either mFOLFOX6 plus bevacizumab or CapeOX plus bevacizumab were decided before study entry. The primary end point was OS, which was analyzed by intention-to-treat. RESULTS: Between June 2012 and September 2019, a total of 165 patients were randomly assigned to either chemotherapy alone (84 patients) or PTR plus chemotherapy (81 patients). When the first interim analysis was performed in September 2019 with 50% (114/227) of the expected events observed among 160 patients at the data cutoff date of June 5, 2019, the Data and Safety Monitoring Committee recommended early termination of the trial because of futility. With a median follow-up of 22.0 months, median OS was 25.9 months (95% CI, 19.9 to 31.5) in the PTR plus chemotherapy arm and 26.7 (95% CI, 21.9 to 32.5) in the chemotherapy-alone arm (hazard ratio, 1.10; 95% CI, 0.76 to 1.59; one-sided P = .69). Three postoperative deaths occurred in the PTR plus chemotherapy arm. CONCLUSION: Given that PTR followed by chemotherapy showed no survival benefit over chemotherapy alone, PTR should no longer be considered a standard of care for patients with CRC with asymptomatic primary tumors and synchronous unresectable metastases.

Oncological outcomes of lateral lymph node dissection (LLND) for locally advanced rectal cancer: is LLND alone sufficient?

BACKGROUND: Lateral lymph node dissection (LLND) has been considered as the standard treatment strategy for locally advanced lower rectal cancer in Japan. Controversy remains around whether all patients require LLND. This study aims to examine the long-term outcomes of patients in which LLND was performed and clarify the value of LLND. METHOD: Consecutive 458 patients with lower rectal cancer who underwent total mesorectal excision (TME) plus LLND from 1992 to 2012 were included. The long-term outcomes and risk factors for recurrent in patients performed TME + LLND were examined. We assessed the impact of LLND on survival using an estimated therapeutic index. RESULTS: The incidence of LLNM was 15.5%. The 5-year RFS and OS rates of patients with LLNM were 40.9% and 47.7%, while patients without LLNM had a good prognosis. The 5-year local recurrence (LR) rate was 9.2%, and independent risk factors for LR were T4 and LLNM. The LR rate of patients with LLNM was high (22.8%). The LLNM rate of the groups with 0, 1, 2, 3, or 4 risk factors (male, tumor location < 4 cm from anal verge, T4, and MLNM) was 3.8%, 9.2%, 18.1%, and 50.0%. The 5-year OS of the groups was 96.2%, 86.1%, 69.7%, and 48.5%. CONCLUSION: Although patients with locally advanced lower rectal cancer who received LLND had a good prognosis, LLND alone was insufficient to control local recurrence in patients with metastatic lateral nodes.

Proposal of a modified subclassification system for stage III colorectal cancer: A multi-institutional retrospective analysis.

AIM: The prognostic value of the stage III subclassification system based on the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma has not yet been clarified. This study aimed to develop a modified system with optimal risk stratification and compare its performance with the current staging systems. METHODS: Clinicopathological data from 6855 patients with stage III colorectal cancers who underwent D3 dissection were collected from a nationwide multicenter database. After determining patient survival rates across 13 divisions based on pathological N stage (N1, N2a, and N2b/N3) and tumor depth (T1, T2, T3, T4a, and T4b), except for T1N2a and T1N2b/N3 due to the small number, we categorized patients into three groups and developed a trisection staging system according to the Akaike information criterion. We then compared the Akaike information criterion of the developed system with those of the current staging systems. RESULTS: The T1N1[rank, 1] division (98.5%) had the most favorable prognosis in terms of 5-year cancer-specific survival, followed by T2N1[2] (93.9%), T2N2a[3] (92.0%), T3N1[4] (87.0%), T3N2a[5] (78.8%), T4aN1[6] (78.7%), T2N2b/N3[7] (77.8%), T4aN2a[8] (75.2%), T4bN1[9] (73.5%), T3N2b/N3[10] (64.7%), T4aN2b/N3[11] (61.5%), T4bN2b/N3[12] (43.0%), and T4bN2a[13] (42.5%). Compared to the categorizations of the Japanese and tumor-node-metastasis systems (Akaike information criterion, 22 684.6 and 22 727.1, respectively), the following stage categorizations were proven to be the most clinically efficacious: T1N1[1 ]-T3N1[4], T3N2a[5 ]-T4bN1[9], and T3N2b/N3[10 ]-T4bN2a[13] (Akaike information criterion, 22 649.2). CONCLUSION: The proposed modified system may be useful in the risk stratification of patients with stage III colorectal cancer who had undergone D3 dissection.

Prognostic Impact of the Length of the Distal Resection Margin in Rectosigmoid Cancer: An Analysis of the JSCCR Database between 1995 and 2004.

OBJECTIVES: The necessary and sufficient length of the distal resection margin (l-DRM) for rectosigmoid cancer remains controversial. This study evaluated the validity of the 3-cm l-DRM rule for rectosigmoid cancer in the Japanese classification of colorectal cancer. METHODS: We retrospectively reviewed 1,443 patients with cT3 and cT4 rectosigmoid cancer who underwent R0 resection in Japanese institutions between 1995 and 2004. We identified the optimal cutoff point of the l-DRM affecting overall survival (OS) rate using a multivariate Cox regression analysis model. Using this cutoff point, the patients were divided into two groups after balancing the potential confounding factors of the l-DRM using propensity score matching, and the OS rates of the two groups were compared. RESULTS: A multivariate Cox regression analysis model revealed that the l-DRM of 4 cm was the best cutoff point with the greatest impact on OS rate (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.00-1.84; P = 0.0452) and with the lowest Akaike information criterion value. In the matched cohort study, the OS rate of patients who had l-DRM of 4 cm or more was significantly higher than that of patients who had l-DRM < 4 cm (n = 402; 5-year OS rates, 87.6% vs. 80.3%, respectively; HR, 1.60; 95% CI, 1.09-2.31; P = 0.0136). CONCLUSIONS: For cT3 and cT4 rectosigmoid cancer, l-DRM of 4 cm may be an appropriate landmark for a curative intent surgery, and we were unable to definitively confirm the validity of the Japanese 3-cm l-DRM rule.

Marked impact of tumor location on the appropriate cutoff values and the prognostic significance of the lymph node ratio in stage III colon cancer: a multi-institutional retrospective analysis.

BACKGROUND: The prognostic significance of lymph node ratio (LNR) is not constant among studies. Exploration of appropriate location-specific cutoffs might be necessary because the number of lymph nodes harvested is generally higher in right than in left colon cancer. We aimed to determine appropriate cutoff values of LNR in right and left colon cancer and to clarify its clinical significance. METHODS: The clinicopathologic data of 5463 patients with stage III colon cancer were collected. The best cutoff for LNR as a prognostic indicator for patients with right and left colon cancer was studied separately. We compared the prognostic impact between LNR and the number of lymph node metastasis using the Akaike information criterion (AIC), and evaluated the prognostic significance of LNR in each stage III subcategory. RESULTS: The best performance was noted when LNR was categorized by cutoffs of 0.16 and 0.22 for right and left colon cancer, respectively. AIC scores were better with these categorizations than with subgrouping by number of positive nodes. LNR-low right colon cancer patients showed better cancer-specific survival than LNR-high in stage IIIA (95.7% vs. 89.3%), IIIB (86.7% vs. 77.2%), and IIIC (71.2% vs. 58.7%). The same results were obtained in left colon cancer patients with stage IIIB (88.3% vs. 80.7%) and IIIC (79.8% vs. 68.4%). CONCLUSIONS: We demonstrated the difference in the appropriate cutoffs of LNR between right and left colon cancer. Categorization by location-specific cutoff of LNR may be useful for risk stratification of patients with stage III cancer.

A New N Staging System for Colorectal Cancer in the Era of Extended Lymphadenectomy.

BACKGROUND: Complete mesocolic excision is becoming popular in colon cancer surgery in Western countries, and in the tumor-node-metastasis (TNM) classification of rectal cancer, a part of the lateral pelvic lymph nodes is classified as regional. However, the appropriateness of TNM staging according to the assessment of nodal status exclusively by extended lymphadenectomy remains unclear. PATIENTS AND METHODS: Using a nationwide multicenter database in Japan, we retrospectively analyzed 6866 patients with stage III colorectal cancer (CRC) treated with extended (D3) dissection. First, the best cutoff values for the number of metastatic nodes were explored. Second, the utility of the metastatic status of the main lymph nodes (i.e., at the origin of the feeding artery) and the lateral pelvic lymph nodes ("jN3" category in the Japanese staging system) as N staging criteria was evaluated. The modified N staging system that had the best risk stratification power was determined according to the Akaike information criterion (AIC). RESULTS: Excellent performance was noted when the number of metastatic nodes was categorized by cutoff values of "3/4" and "6/7." Categorization of nodal metastasis was proven the most clinically efficacious when classified as modified-N1 (N1 and jN3-negative), modified-N2a (N2a and jN3-negative), and modified-N2b (N2b and/or jN3-positive; AIC, 22,810.8), rather than the classification based on the TNM (AIC, 22,849.2) or Japanese staging system (AIC, 22,811.1). CONCLUSIONS: We structured a modified N staging system according to the number and extent of lymph node metastases. The modified system may be used in stage III cases for precise risk stratification.

[Gallbladder Malignant Lymphoma Diagnosed after Surgery for Acute Cholecystitis - A Case Report].

An 84-year-old man visited our hospital with epigastralgia.Levels of hepatic and biliary enzymes and CRP were elevated, as detected by a blood test.On a CT scan, a swollen gallbladder with stones was detected.The patient was admitted to the hospital with a diagnosis of Grade I acute cholecystitis.Conservative treatment was continued with antibiotic administration and the patient was discharged from the hospital with improvement on day 6 after admission.Three months later, the patient underwent laparoscopic cholecystectomy.In the gallbladder, a 45×45 mm tumor was found.Upon pathological examination, diffuse proliferation of lymphocyte-like heterotypic cells and subserosal invasion were observed.Immunohistochemistry results were negative for MUM1 and positive for CD10 and Bcl6 markers.A malignant diffuse large B-cell lymphoma was diagnosed.We experienced a case of malignant lymphoma of the gallbladder diagnosed after surgery for acute cholecystitis, which we herein report with literature consideration.

[A Case of Neuroendocrine Tumor G1 of the Ileum with Multiple Liver Metastases].

A 74-year-old man was admitted to our hospital with multiple liver tumors detected by routine ultrasonography. Colonoscopy showed a type 2 tumor measuring approximately 25mm in diameter at the terminal ileum. The biopsy specimen showed neuroendocrine tumor(NET)G1. The patient was diagnosed with NET G1 of the ileum with multiple liver metastases. Thus, he underwent ileocecal resection with lymph node dissection and liver(S2)biopsy. A tumor was observed at the terminal ileum with serosal invasion, and the mesenteric lymph nodes were enlarged. Multiple liver metastatic tumors were observed in S2, S5, and S8. The patient was diagnosed with NET G1 of the ileum, T4N1M1, Stage Ⅳ. He is receiving octreotide therapy and has maintained stable disease for about 24 months.

Prediction of lateral pelvic lymph node metastasis from lower rectal cancer using magnetic resonance imaging and risk factors for metastasis: Multicenter study of the Lymph Node Committee of the Japanese Society for Cancer of the Colon and Rectum.

PURPOSE: The goal of the study was to examine prediction of lateral pelvic lymph node (LPLN) metastasis from lower rectal cancer using a logistic model including risk factors for LPLN metastasis and magnetic resonance imaging (MRI) clinical LPLN (cLPLN) status, compared to prediction based on MRI alone. METHODS: The subjects were 272 patients with lower rectal cancer who underwent MRI prior to mesorectal excision combined with LPLN dissection (LPLD) at six institutes. No patients received neoadjuvant therapy. Prediction models for right and left pathological LPLN (pLPLN) metastasis were developed using cLPLN status, histopathological grade, and perirectal lymph node (PRLN) status. For evaluation, data for patients with left LPLD were substituted into the right-side equation and vice versa. RESULTS: Left LPLN metastasis was predicted using the right-side model with accuracy of 86.5%, sensitivity 56.4%, specificity 92.7%, positive predictive value (PPV) 61.1%, and negative predictive value (NPV) 91.2%, while these data using MRI cLPLN status alone were 80.4, 76.9, 81.2, 45.5, and 94.5%, respectively. Similarly, right LPLN metastasis was predicted using the left-side equation with accuracy of 83.8%, sensitivity 57.8%, specificity 90.4%, PPV 60.5%, and NPV 89.4%, and the equivalent data using MRI alone were 78.4, 68.9, 80.8, 47.7, and 91.1%, respectively. The AUCs for the right- and left-side equations were significantly higher than the equivalent AUCs for MRI cLPLN status alone. CONCLUSIONS: A logistic model including risk factors for LPLN metastasis and MRI findings had significantly better performance for prediction of LPLN metastasis compared with a model based on MRI findings alone.

Preplanned safety analysis of the JFMC37-0801 trial: a randomized phase III study of six months versus twelve months of capecitabine as adjuvant chemotherapy for stage III colon cancer.

BACKGROUND: Six months of adjuvant chemotherapy is regarded as the standard of care for patients with stage III colon cancer. However, whether longer treatment can improve prognosis has not been fully investigated. We conducted a phase III study comparing 6 and 12 months of adjuvant capecitabine chemotherapy for stage III colon cancer, and report here the results of our preplanned safety analysis. METHODS: Patients aged 20-79 years with curatively resected stage III colon cancer were randomly assigned to receive 8 cycles (6 months) or 16 cycles (12 months) of capecitabine (2500 mg/m2/day on days 1-14 of each 21-day cycle). Treatment exposure and adverse events (AEs) were evaluated. RESULTS: A total of 1304 patients (642 and 636 in the 6-month and 12-month groups, respectively) were analyzed. The most common AE was hand-foot syndrome (HFS). HFS, leukocytopenia, neutropenia, and hyperbilirubinemia (any grade) occurred more frequently in the 12-month group than in the 6-month group. HFS was the only grade ≥3 AE to have a significantly higher incidence in the 12-month group (23 vs 17%, p = 0.011). The completion rate for 8 cycles was 72% in both groups, while that for 16 cycles was 46% in the 12-month group. HFS was the most common AE requiring dose reduction and treatment discontinuation. CONCLUSIONS: Twelve months of adjuvant capecitabine demonstrated a higher cumulative incidence of HFS compared to the standard 6-month treatment period, while toxicities after 12 months of capecitabine were clinically acceptable. TRIAL REGISTRATION: UMIN-CTR, UMIN000001367.

[The Case of HER2 Positive Advanced Gastric Cancer with Para-Aorta Lymph Node Recurrence Responding to Capecitabine plus CDDP plus Trastuzumab Chemotherapy].

We report the case of a 69-year-old man diagnosed with gastric cancer.The patient underwent distal gastrectomy(D2) and Billroth I reconstruction in March, 2010. Postoperative histopathological examination indicated M, Ant, Type 5, 100×50 mm, pap>por2>sig, T4aN3M0, pStage III C.We performed S-1 therapy as adjuvant chemotherapy.Abdominal CT showed para-aortic lymph node recurrence in February, 2015. Since HER2 protein was overexpressed in primary tumor immunostaining, he was treated with capecitabine plus CDDP plus trastuzumab therapy.After the chemotherapy, CEA levels decreased to the normal range and the enlarged lymph node was remarkably decreased in size in May, 2015.T he patient is alive 24 months after the chemotherapy with no evidence of recurrence.

The important risk factor for lateral pelvic lymph node metastasis of lower rectal cancer is node-positive status on magnetic resonance imaging: study of the Lymph Node Committee of Japanese Society for Cancer of the Colon and Rectum.

PURPOSE: This study seeks to evaluate lateral pelvic lymph node (LPLN) and perirectal lymph node (PRLN) status on magnetic resonance imaging (MRI) as potential risk factors for lymph node metastasis. METHODS: The subjects were 394 patients with lower rectal cancer who underwent MRI prior to mesorectal excision (combined with lateral pelvic lymph node dissection in 272 patients) at 6 institutes. No patients received neoadjuvant therapy. Cases were classified as cN(+) and cN(-) based on the short axis of the largest lymph node ≥5 and <5 mm, respectively. LPLN and PRLN status and other clinicopathologic factors were analyzed by multivariate logistic regression. The importance of identified risk factors for lymph node metastasis was examined using the area under the curve (AUC). RESULTS: Independent risk factors for right LPLN metastasis included histopathological grade (G3 + G4), pPRLN(+), M1, cLPLN(+) [odds ratio (OR) 10.73, 95 % confidence interval (CI) 4.59-27.1], and those for left LPLN metastasis were age (<64), histopathological grade (G3 + G4), pPRLN(+), and cLPLN(+) (OR 24.53, 95 % CI 9.16-77.7). ORs for cLPLN(+) were highest. The AUCs for right and left cLPLN status of 0.7484 (95 % CI 0.6672-0.8153) and 0.7904 (95 % CI 0.7088-0.8538), respectively, were significantly higher than those for other risk factors. In contrast, the ORs for cPRLN(+) and cPRLN status of 2.46 (95 % CI 1.47-4.18) and 0.6396 (95 % CI 0.5917-0.6848) were not much higher than for other factors. CONCLUSIONS: An LPLN-positive status with a short axis ≥5 mm on MRI is an important predictor of LPLN metastasis, but PRLN status is not a strong predictor of PRLN metastasis.

[A Case of Stage IV Gastric Cancer Successfully Treated Using Salvage Surgery after S-1/CDDP Therapy].

A 75-year-old man admitted for left lateral abdominal pain was found to have advanced poorly differentiated gastric adenocarcinoma with abdominal para-aortic and Virchow's lymph node metastases, which was diagnosed to be clinical Stage IV (T3N3H0M1[LYM]). As curative surgery was not deemed possible, we started chemotherapy administration using S-1 (120mg/day)administered orally for 3 weeks and cisplatin(CDDP 100mg/body)administered intravenously on day 8. After 6 courses of chemotherapy, a CT scan showed that all lymph nodes metastases had disappeared, resulting in downstaging to clinical Stage II (T3[SE]N0H0P0M0). Thus, we performed total gastrectomy, lymph node dissection(D2), and splenectomy. Histological findings showed no residual tumor cells in any of the lymph nodes. However, cancer cells remained in the primary gastric lesion. The pathological response to chemotherapy was judged to be Grade 2. The patient has been recurrence-free for 5 years after surgery.

Selection of Lymph Node-Positive Cases Based on Perirectal and Lateral Pelvic Lymph Nodes Using Magnetic Resonance Imaging: Study of the Japanese Society for Cancer of the Colon and Rectum.

PURPOSE: To investigate the optimum cutoff for lymph node size to identify cases positive for perirectal lymph node (PRLN) and lateral lymph node (LPLN) metastasis of lower rectal cancer on magnetic resonance imaging (MRI). METHODS: The subjects were 449 patients who underwent preoperative MRI. Mesorectal excision was performed in all patients (combined with lateral pelvic lymph node [LN] dissection in 324) between 2004 and 2013 at 6 institutes. Cases were classified as cN positive and cN negative on the basis of the short axis of the largest LN being greater than or equal to a cutoff or less than a cutoff, respectively. PRLN and LPLN diagnoses using 5 and 10 mm cutoffs were compared with histologic diagnoses. Of the 449 patients, 55 received preoperative chemoradiotherapy. MRI was only performed after this therapy in all of these patients. RESULTS: For PRLNs, 5 and 10 mm cutoffs gave area under the curve (AUC) values of 0.6364 and 0.5794, respectively. The 5 mm cutoff gave a significantly higher AUC value (P = 0.0152), with an accuracy of 63.7 %, sensitivity of 72.6 %, and specificity of 54.7 %. For right LPLNs, the respective AUC values were 0.7418 and 0.6326 (P = 0.0034), and the variables (5 mm cutoff) were 77.6, 68.6, and 79.7 %. For left LPLNs, AUC values were 0.7593 and 0.6559, respectively (P = 0.0057), and the variables (5 mm cutoff) were 79.3, 70.8, and 81.0 %. CONCLUSIONS: Identification of LN-positive cases on the basis of PRLN and LPLN sizes was superior at a short-axis 5 mm cutoff. Size-based diagnosis of LN metastasis is simple and useful, but further investigation is needed to clarify whether it is superior to diagnosis based on morphology, such as shape, border, and signal intensity.

[Experience of the Pharmacotherapy against Appendix and Sigmoid Colon Signet Ring Cell Carcinoma with the Peritoneal Dissemination].

We report 2 cases of signet ring cell carcinoma of the appendix and colon. Case 1: A 61-year-old man was admitted for lower abdominal pain. Colonoscopy revealed an elevated lesion in the orifice of the appendix. Signet ring cell carcinoma was diagnosed on biopsy. The surgical findings showed multiple peritoneal dissemination nodules, while the primary tumor was unresectable owing to extensive invasion into the retroperitoneum. The histopathological findings were signet ring cell carcinoma, T4b (retroperitoneum), NX, P3, Stage Ⅳ. Although the patient received 14 courses of treatment with S-1 as postoperative chemotherapy, he died of his illness at 32 postoperative months. Case 2: A 76-year-old man was admitted for abdominal pain. Perforation of the lower gastrointestinal tract was diagnosed on abdominal CT, and an emergency operation was performed. The surgical findings demonstrated a large number of peritoneal dissemination nodules, cecal invasion of a sigmoid tumor, and perforation of the ascending colon. The primary tumor was thought to be unresectable, and the perforated segment was resected. The histopathological findings were signet ring cell carcinoma, T4b (cecum), NX, P3, Stage Ⅳ. Although 11 courses of treatment using FOLFIRI+Bev were administered as postoperative chemotherapy, the patient died of his illness at 26 postoperative months.