遊休農地の活用策の一つとして植樹が挙げられるが，当該地では表層に硬盤が形成されていることがあり，植栽木の生残・成長に悪影響を及ぼすことがある。本研究では，エゾヤマザクラ植栽木の主軸の枯死・萌芽と土壌貫入抵抗の関係について調査した。畑地として利用されていた遊休農地内において，耕耘を行った区画と耕耘をしなかった区画を調査対象とした。耕耘処理区の深さ0.1 mまでのNc値は無処理区（対照）の値より低い値であり，耕耘処理で硬盤が破壊されたことが示唆された。調査木の主軸の枯死は，耕耘処理の方が無処理区よりも少なかった。主軸枯れした調査木では萌芽が生じる傾向にあり，萌芽枝の成長量は0.1 mまでのNc値が低いほど高い値を示す傾向であった。したがって，遊休農地において植栽を行う際には，表土層での耕耘処理を行うことが有効である。

Background/Aim: Laparoscopic gastrectomy (LG) is more frequently associated with postoperative liver enzyme elevation (PLEE) than open gastrectomy in phase III clinical trials for Japanese gastric cancer patients. The aim of this study was to determine the risk factors for PLEE after LG for gastric cancer. Patients and Methods: This study enrolled 153 consecutive patients with gastric cancer who underwent LG. The patient characteristics, the liver retraction method [silicone disc (SD) or Nathanson liver retractor (NLR)], and perioperative outcomes were compared between patients with and without PLEE. Results: PLEE was observed in 26 patients (17%). The patients with PLEE exhibited longer operative times (p=0.005) and more frequent use of the NLR for liver retraction (p=0.022). In the multivariate analysis, liver retraction using the NLR (p=0.003) and aberrant left hepatic artery (ALHA) ligation (p=0.042) were independent risk factors of PLEE. Conclusion: Liver retraction with the SD during LG was shown to be the safer method that is less likely to cause postoperative liver dysfunction. ALHA preservation may contribute to avoiding postoperative liver dysfunction.

Background/Aim: DNA mismatch repair (MMR) deficiency has received increasing attention as a biomarker of anti-PD-1 treatments of solid tumors including gastric cancer (GC). However, efficient screening has not been established. Patients and Methods: A total of 513 patients were tested for the expression of MMR proteins by immunohistochemistry to identify MMR deficient GC. Development of a prediction model was attempted using the common clinicopathological features. Results: In total, 11% (57/513) of the patients showed loss of expression of either one or more MMR proteins (MMR protein deficiency; MMR-D). Multivariate analysis demonstrated that age (≥70 years), sex (female), tumor location (lower 1/3), depth invasion (low, T1/T2/T3), and absence of distant metastasis were significantly independent predictive factors of MMR-D GCs. The MMR-D GC probability estimated by the prediction model ranged from 0.4% to 62.2%, and the area under the curve of the receiver operating characteristics curve was 0.82 (95% confidence interval=0.75-0.87). Conclusion: Our prediction model can sufficiently and efficiently identify MMR-D GCs using clinical features.

Objectives: The pre-operative diagnostic value of detecting lateral pelvic lymph node (LPLN) metastasis with magnetic resonance imaging, multidirectory computed tomography, and positron emission tomography/computed tomography was investigated in lower rectal cancer patients. Methods: We retrospectively evaluated, using the three different modalities, the metastatic status of LPLNs in four regions, including both the internal iliac and the obturator, in 46 patients affected by lower rectal cancer patients who underwent LPLN dissection. The size inclusion criterion for LPLN metastasis was set at 6 mm in the short axis diameter. Histological examination was performed for determining the false positive and negative rate of LPLNs metastasis detection. Results: Among 184 LPLNs regions, 17 (9%) were positive for metastasis. The region-based sensitivity, specificity, and accuracy rate did not differ among the three tested diagnostic modalities. Moreover, a significant increase in these rates could not be observed when the modalities were combined. Of 184 regions, 8 (4.4%) were false negative, whereas 2 (1.1%) were false positive. The histological pattern of metastatic regions did not differ in 8 false negative LPLNs. Conclusions: Each modality had a similar detection power for LPLNs metastasis, with a cut-off value at 6 mm in the short axis diameter. However, the sensitivity of all the modalities was slightly low, along with the number of false negative LPLNs. Further reduction of the false negative rate with these modalities may be difficult because of an inherent limitation of current imaging technologies to accurately detect lymph node metastases.

Laparoscopic esophagojejunostomy is a challenging procedure because of its technical difficulty. We herein report a new method involving circular-stapled anastomosis using a hand-sewn suture with four stay-sutures and evaluate its outcomes. Esophagojejunostomy using this method was performed in 36 consecutive patients with clinical stage I gastric cancer at the authors’ institutions. The key feature of our procedure was the placement of four full-thickness stay-sutures to anchor the esophageal stump prior to the hand-sewn purse-string suture. The median operation time and mean anvil fixation time were 315.5 and 21.9 min, respectively. The mortality rate was 0%, although anastomotic leakage following esophagojejunostomy was observed in 1 patient (2.8%), and anastomotic stenosis was observed in another patient (2.8%). Intracorporeal esophagojejunostomy using the four stay-sutures method appears to be safe and feasible. We believe that this method enables hand-sewn purse-string suturing to be performed more easily.

Aim: To evaluate the efficacy and safety of third-line chemotherapy (CTx) for patients with unresectable or recurrent gastric cancer (GC) refractory to S-1 with or without platinum and taxanes. Patients and Methods: We retrospectively analyzed clinicopathological and survival data of 26 patients who underwent third-line CTx. Results: Irinotecan therapy (odds ratio=0.12, 95% confidence interval=0.02-0.38; p<0.01) and ≥2 cycles of third-line CTx (odds ratio=0.01, 95% confidence intervaI=0.01-0.11; p<0.01) were independent predictors of longer progression-free survival in multivariate Cox regression analysis. In 18 patients (69%) receiving irinotecan, the overall response rate was 11%, and the disease control rate was 44%. Median progression-free and overall survival were 3.5 and 11.3 months, respectively. Ten patients (56%) had grade 3-4 toxicities, which were managed. Conclusion: Irinotecan therapy may become optimal and tolerated in the third-line setting to prolong progression-free survival by increasing the number of treatment cycles.

In this study, we describe a 60-year-old man with a giant retroperitoneal liposarcoma with multilocular cysts. He was admitted to our hospital because of a 5-month history of abdominal distention. Abdominal computed tomography revealed a giant lobulated cystic mass occupying the retroperitoneal space that contained partially solid fat components. Magnetic resonance imaging indicated that this complex mass exhibited a low signal intensity on a T1-weighted image, whereas it exhibited a high and focally intermediate signal intensity on a T2-weighted image. This patient was diagnosed with a mucinous type of retroperitoneal sarcoma, which was then resected. During surgery, the tumor was isolated from the retroperitoneum and other organs, but the detachment was required only because of fixation around the left external iliac artery. The histological diagnosis was a well-differentiated liposarcoma with multilocular cysts that contained old bloody, serous, and mucinous fluids, which are a rare phenomenon in liposarcoma. This case indicates that retroperitoneal liposarcoma should also be considered as a differential diagnosis of retroperitoneal cystic mass.

Background/Aim: Postoperative chemotherapy is an absolutely imperative treatment for advanced esophageal cancer patients, while preoperative chemotherapy is the standard therapy for clinical stage II/III esophageal squamous cell carcinoma (ESCC) in Japan. The aim of this study was to report the effect of postoperative chemotherapy on survival after esophagectomy due to thoracic esophageal squamous cell carcinoma. Patients and Methods: One hundred thirteen consecutive patients with esophageal carcinoma who underwent esophagectomy were included. Several regiments were performed at various times. Results: Adjuvant chemotherapy brought a significantly superior overall survival (p=0.002), although there was no significant difference in cancer-specific survival (p=0.054) for clinical stage II or stage III esophageal cancer patients. Depth of invasion (p=0.003), number of lymph node metastases (p=0.048), and venous invasion (p<0.001) were risk factors for recurrence in the adjuvant-chemotherapy group with positive lymph nodes. Additionally, a not well-differentiated type, lymphatic and venous invasions were risk factors for recurrence in the surgery-alone group without positive lymph nodes. Conclusion: Postoperative adjuvant chemotherapy contributes to the prognosis of clinical stage II or III esophageal cancer patients.

Effects of tree windbreaks on crop production vary from field to field. However, considerable labor is required to evaluate the effects of windbreaks by conducting yield surveys in multiple fields. The present study aimed to clarify whether the spatial pattern of windbreak effects on maize growth can be evaluated using an unmanned aerial vehicle (UAV) in a field with a windbreak in Hokkaido, northern Japan. We mapped normalized difference vegetation index (NDVI) distribution in the field using a UAV and conducted micrometeorological observation and survey of growth and yield. We found that the windbreak positively affected maize growth by increasing soil temperature at 3–5 H (H = windbreak height) and negatively by shading at approximately 1 H. NDVI estimated using the UAV was high in June and low in September, suggesting that the growth rate of maize at 3–5 H was higher than that at 6–12 H. NDVI was significantly correlated to dry matter content of maize, although the area shaded by the windbreak during observation could not be used for analysis. These results indicate that a UAV was successful to grasp spatial pattern of windbreak effects on maize growth. This study shows the potential of a UAV to be useful for saving time and money when we evaluate the effects of windbreaks on crop growth.

【目的】実地医療における切除不能進行再発大腸癌に対するlate lineの治療成績を明らかにする．【対象・方法】2013年７月～2016年12月の間にlate lineとしてregorafenib，trifluridine / tipiracil（TFTD）の少なくとも１剤を使用した切除不能進行再発大腸癌41例を対象に，診療録からデータを抽出し，後方視的に解析した．【結果】Regorafenib先行群25例，TFTD先行群16例の間で無増悪生存期間，全生存期間ともに有意差を認めなかった．RegorafenibまたはTFTDのみが使用された22例より，２剤が使用された19例の方が全生存期間が延長していた（中央値20.8カ月vs．6.4カ月，p=0.02）．【結語】大腸癌化学療法のlate lineにおいて，regorafenibとTFTDを使い切ることが，生存期間の延長に繋がる可能性が示唆された．

Aortoesophageal fistula (AEF) is a life-threatening late complication that can occur after thoracic endovascular aortic repair (TEVAR). More data are required to identify the optimal treatment strategy for AEF developed after TEVAR. The aim of this study was to clarify the current status of surgical treatments for AEF developed after TEVAR and the outcomes of these treatments. The Japan Esophageal Society conducted a questionnaire survey targeting authorized or semi-authorized institutes at Authorized Institutes for Board Certified Esophageal Surgeons. Thirty-nine patients with AEF developed after TEVAR were identified from 15 institutes. Data on patient demographics, treatment performed, and survival rate were obtained by the questionnaire. The Kaplan–Meier method was used for survival analysis and differences in the survival rates. Esophagectomy and aortic replacement were performed in 32 and 22 patients, respectively, and 22 underwent both procedures. Postoperative complications were observed in 24 patients (75.0%). Complications with Clavien–Dindo Grade III or higher were observed in 53.1% of patients. Operative and hospital mortality rates were 3.1% and 18.8%, respectively. The survival rate in patients who underwent esophagectomy was higher than in those who did not (P < 0.0001). The survival of patients who underwent both esophagectomy and aortic replacement was also higher than in those who did not (P < 0.0001). Esophagectomy combined with aortic replacement can offer a long-term treatment strategy with higher survival rates in patients who develop AEF after TEVAR. Because of the high incidence of postoperative morbidity and mortality, these types of surgery should only be performed in centers with both experienced esophageal and cardiovascular surgical teams.

多雪地域の重粘土地における樹木の植栽方法検討のため，北海道当別町にある「道民の森・神居尻地区」の牧野跡地において，植栽基盤整備しない区画（無処理区）と，地表を畝上げ及び耕耘の処理を行った区画（畝上げ区と耕耘区）にコバノヤマハンノキを植栽し，その後6年間の生育状況を調査した。本試験地の土壌は固相率が高く気相率が低いのに加え，難透水性の重粘土であり，地表下10～20 cmに耕盤層が認められた。畝上げ区の土壌水分（pF値）は植物の生育にとって適正な範囲に収まることが多かったが，耕耘区では飽和状態になることもあった。植栽木には，越冬期間中に主軸折れ等の雪害を受けるものが多数あった。雪害を受けた個体数は最大積雪深が大きい年ほど多く，また樹高が高くなるほど雪害を受けにくくなる傾向が認められた。また，被害個体数は畝上げ区よりも耕耘区と無処理区で多い傾向だった。3処理区で樹高成長に大きな差は認められず，直径成長に差が現れた。直径成長の差は形状比の違いとなり，雪害への感受性に反映した。以上の結果から，多雪地域の重粘土地では耕耘よりも畝上げが効果的な植栽基盤整備方法として提案できる。

The present study aimed to enrich circulating tumor cells (CTCs) from blood samples using a new size-sorting CTC chip. The present study also set out to identify a blood sensitivity marker for the immune checkpoint inhibitor nivolumab in patients with advanced, pre-treatment lung cancer. The CTC sorting efficacy of the chip was investigated and the large cell fraction of blood samples from 15 patients with pre-treatment lung cancer who were later administered nivolumab were purified. The expression levels of carcinoembryonic antigen (CEA), human Telomerase Reverse Transcriptase (hTERT), cytokeratin19 (CK19), and programmed death ligand-1 (PD-L1) were investigated to clarify the association between these CTC markers and the clinical response to nivolumab. The CTC chip effectively enriched cells from lung cancer cell line PC-9. The large cell fraction had a high expression of CEA and hTERT, with the former being significantly associated with the clinical response to nivolumab. The expression of CEA and hTERT in CTCs derived from the blood of a patient with lung cancer were also validated. The evaluation of CEA and possibly hTERT in CTCs collected by the CTC chip may represent a promising predictive blood marker for sensitivity to nivolumab. To the best of our knowledge this is the first report to describe the predictive CTC marker for nivolumab in pre-treatment patients.

Background/Aim: Advances in chemotherapy for gastric cancer have encouraged surgeons to perform conversion surgery following a response to first-line chemotherapy in patients with initially unresectable gastric cancer. In this study we evaluated the efficacy of conversion surgery following first- or second-line chemotherapy for unresectable gastric cancer. Patients and Methods: We retrospectively analyzed clinicopathological and survival data of 94 patients with unresectable gastric cancer treated with first- (n=94) or second-line (n=43) chemotherapy. Results: Patients who converted to surgery following first- (n=26) or second-line (n=5) chemotherapy had significantly longer survival times than those treated with chemotherapy alone (n=63) (p<0.01). Survival length did not differ significantly between patients converted to surgery following first- and second-line chemotherapy. Among 31 patients who underwent conversion surgery, one initial non-curative factor (odds ratio(OR)=0.49; 95% confidence interval (95%CI)=0.22-0.95; p=0.03) was the only significant independent predictor of longer survival in multivariate Cox regression analysis. Conclusion: Patients with unresectable gastric cancer initially exhibiting one noncurative factor may obtain survival benefit from conversion surgery after a response to both first- and second-line chemotherapy.

BACKGROUND/AIM:We evaluated the survival benefit of splenectomy in patients with esophagogastric junction (ECJ) carcinoma.PATIENTS AND METHODS:We retrospectively examined clinicopathological and survival data for 60 surgically-treated patients with ECJ carcinoma.RESULTS:The 5-year overall survival (OS) rate was 47%. Splenectomy was performed in 20 patients (30%). Multivariate Cox regression analysis revealed splenectomy (odds ratio (OR), 2.70; 95% confidence interval (CI)=1.06-7.17; p=0.04) and venous invasion (OR=3.03; 95%CI=1.20-9.27; p=0.02) as significant independent predictors of poorer OS. Splenic hilar lymph node metastasis was not observed. Multivariate logistic regression analysis identified perioperative blood transfusion (BTF) as a significant independent factor associated with splenectomy.CONCLUSION:The survival benefit of splenectomy in ECJ carcinoma patients may decrease with increasing frequency of perioperative BTF for blood loss. We recommend that splenectomy should be performed carefully when indicated by the extent or invasion of EGJ carcinoma.

The liver is the most common metastatic site for colorectal cancer(CRC).The 5-year survival rate of resected cases has been reported to be about 40%.Hepatic lymph node metastasis is reportedly associated with a poor prognosis in patients with liver metastases of CRC.The incidence of hepatic lymph node involvement in patients with liver metastases of CRC ranges from 5% to 28%.However, few reports have focused on hepatic lymph node involvement in patients with resectable liver metastasis who have undergone preoperative chemotherapy.This retrospective study was undertaken to address this issue.The subjects were 33 consecutive patients who had undergone the resection of liver metastases of CRC with hepatic lymph node sampling after preoperative chemotherapy between 2001 and 2016. Hepatic lymph node metastasis was confirmed in only one patient(3%).There was no significant difference in the frequency of hepatic lymph node metastasis between the cases with or without preoperative chemotherapy.The further collection of data is warranted to elucidate the significance of hepatic lymph node involvement in patients with liver metastases of CRC treated with preoperative chemotherapy.

The basic treatment for retroperitoneal liposarcoma is surgical therapy. Since the administration of trabectedin for soft tissue sarcoma has been approved, another option for soft tissue sarcoma treatment has been added. We report a case of radical resection after trabectedin therapy for initially unresectable retroperitoneal liposarcoma. A 61-year-old man was admitted to our hospital with an abdominal tumor. A tumor, about 50 cm in maximal diameter, that was not movable throughout the abdomen was observed. Computed tomography revealed a giant tumor almost occupying the entire abdomen, and he was diagnosed with retroperitoneal liposarcoma based on histopathological examination of a puncture specimen. Chemotherapy containing trabectedin was administered. At the end of 8 courses, he achieved stable disease. However, the movability improved, and surgery was performed. The procedure was tumor resection with right kidney, adrenal gland, and inferior vena cava resection. Histopathological examination revealed a mixed type of well differentiated type and dedifferentiated type. The patient is alive without recurrence 10 months after the surgery.

The relationship between thymidine phosphorylase (TP) and angiogenesis at the early stage of esophageal squamous cell carcinoma has been unclear.

This retrospective study evaluated an appropriate surgical treatment in patients with perforated gastric cancer. The clinicopathological and survival data on 17 perforated gastric cancer patients treated with surgery were analyzed. The one-stage or two-stage gastrectomy was performed in 8 and 5 patients, respectively. The omental patch repair was performed in 4 patients. In univariate analysis, non-curative(R2)resection with gross residual tumor(p<0.01)and postoperative complications( p=0.01)were found to be significant unfavorable factors for overall survival(OS). In multivariate analysis, R2 resection was identified to be an only independent significant unfavorable factor for OS. Patients who underwent curative(R0) resection had long-term survival, while patients with R2 resection and postoperative complication had limited survival times. These results suggest that R0 resection may be optimal to improve survival in patients with perforated gastric cancer, regardless of whether patients underwent a one-stage or two-stage gastrectomy based on the patient's condition.

Smoking cigarettes and drinking alcoholic beverages are considered very important risk factors for adverse health effects, such as many types of cancer and cardiovascular disease. In this study, we evaluated the influence of smoking and drinking cessation on risk of esophageal cancer, by means of meta-analysis. We extracted 205 studies by conducting a systematic literature search. Thirty-five studies that estimated risk reduction following smoking cessation and 18 studies conducted following drinking cessation were identified in the literature review. Former smokers had a significantly lower summary risk ratio (RR) than current smokers [RR 0.74, 95% confidence interval (CI) 0.68–0.80]. In subgroup analysis of Japanese smokers, squamous cell carcinoma, and adenocarcinoma, RRs for former smokers versus current smokers were 0.65 (95% CI 0.51–0.83), 0.60 (95% CI 0.50–0.72), and 0.93 (95% CI 0.84–1.03), respectively. The summary RR between former alcohol drinkers and current drinkers was not significant (RR 1.09, 95% CI 0.94–1.26). In our analysis of time since drinking cessation, drinkers who had stopped consuming alcohol for 5 years or more had a significantly lower summary RR than current drinkers (RR 0.78, 95% CI 0.66–0.93). Summary RR for drinkers who stopped for 10 years or more versus current drinkers was 0.65 (95% CI 0.57–0.74). Our investigation found that smoking cessation lowers esophageal cancer incidence. We also found that esophageal cancer incidence risk could be decreased in current drinkers by cessation of alcohol consumption for 5 years or more.