[Launching Robot-Assisted Laparoscopic Surgery for Rectal Cancer in Our Hospital-Short-Term Results]

Robot-assisted laparoscopic surgery(RALS)for rectal cancer has been covered by National Health Insurance in Japan since April 2018. We launched RALS in our hospital in October 2019 and now report the short-term results(up to January 2020). Altogether, 15 consecutive patients(12 men, 3 women: median age 70 years)with rectal cancer underwent RALS during that period. For the first 2 cases, we performed RALS under the instruction of an experienced proctor from another institution. Among the 15 patients, 6 underwent high anterior resection and 9 low anterior resection. Median operating time was 358 min, median intraoperative blood loss was 0 mL, and there were no apparent intraoperative complications. Median postoperative length of hospital stay was 13 days, and only 1 patient developed a high-grade complication(Clavien-Dindo Grade Ⅲb)postoperatively. Hence, RALS for rectal cancer was launched successfully in our institution.

[A Case of Slow-Growing Intrahepatic Cholangiocarcinoma after Resection of Gastric Cancer]

An 83-year-old woman was given a diagnosis of gastric cancer and received distal gastrectomy 9 years ago. Three years later, CT revealed a tumor measuring 13 mm in diameter in hepatic segment 7. She was followed for 5 years, and the size of the tumor did not change. Eight years later after gastrectomy, the tumor size slightly enlarged to 17 mm, and biopsy revealed adenocarcinoma. The patient underwent liver resection of segment 7. The pathological diagnosis was well differentiated intrahepatic cholangiocarcinoma(ICC). No sign of recurrence has been found during a 1-year. This case, in which the patient was followed for 5 years before curative surgical treatment, is significant, because it demonstrates the slow-growing nature of ICC.

Abstract 264: Long noncoding RNA LNC01534 regulates cancer stem cells in colorectal cancer

Introduction The clinical importance of cancer stem cells (CSCs) has been widely reported, and clinical studies targeting CSCs are in progress. Additionally, accumulating evidence suggests that long noncoding RNAs (lncRNAs) have essential roles in cancer initiation and progression, while deregulated lncRNA expression is found in a variety of cancer types. In this study, we focused on lncRNAs regulating CSCs in colorectal cancer (CRC).

Objectives To identify the lncRNAs associated with CSCs and to evaluate their clinical relevance and function.

Materials and Methods We separated CSCs and other cells in CRC using the ornithine decarboxylase (ODC) degron system to visualize CSCs based on the correlation between low proteasome activity and CSC properties. We performed comprehensive gene analysis comparing CSCs and other cells to identify a candidate lncRNA that regulates the stemness of CRC cells. Finally, we analyzed the clinical relevance and function of the lncRNA.

Results The lncRNA LNC01534 showed high expression in CSCs compared with the level in other CRC cells. Using gene expression and clinical data from the Cancer Genome Atlas Project for CRC patients, we showed that LNC01534 was associated with overall survival in CRC. LNC01534 was also associated with overall survival and disease-free survival in 187 separate CRC samples. Functional studies revealed that the loss of LNC01534 function reduced proliferation and arrested the cell cycle in CRC cells. Furthermore, genes that underwent expression changes upon the knockdown of LNC01534 were evaluated by RNA-seq. This showed that the knockdown of LNC01534 affected the expression of genes related to endoplasmic reticulum (ER) stress and autophagy. Specifically, the expression levels of HSPA5, LC3-I, p62, and Beclin-1–genes related to ER stress and autophagy–increased upon suppressing LNC01534.

Conclusions We demonstrated the clinical and biological relevance of LNC01534 in association with CSCs, and discovered the effect of LNC01534 on ER stress and autophagy to maintain stemness in CRC.

Citation Format: Masahisa Ohtsuka, Wu Xin, Momoko Ichihara, Haruka Hirose, Hidekazu Takahashi, Chu Matsuda, Hiroki Akamatsu, Tsunekazu Mizushima, Yuichiro Doki, Hirofumi Yamamoto. Long noncoding RNA LNC01534 regulates cancer stem cells in colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 264.

Effects of Daikenchuto on postoperative gastrointestinal motility in colorectal carcinoma patients with abdominal pain and distension: a prospective, randomized trial

PURPOSE

To investigate the efficacy and safety of Daikenchuto (DKT) for colorectal cancer patients undergoing surgery with the potential risk of postoperative ileus (POI).

METHODS

Colorectal cancer patients with abdominal pain and distention, scheduled for surgery, were randomly assigned to a DKT group or a control group. Patients assigned to the DKT group were given 15 g of DKT per day during the perioperative period. We then compared the perioperative gastrointestinal symptoms between the two groups.

RESULTS

The aim for a sample size of 30 patients per group was not reached in time, so we conducted an analysis on 16 patients in each group. The visual Analogue Scale scores for abdominal pain and distention were similar in the two groups. The number of bowel movements per day on postoperative days (PODs) 1, 2, and 6 were significantly lower in the DKT group. The incidence of a sensation of incomplete bowel evacuation on PODs 3 and 28 was also significantly lower in the DKT group. There were no adverse events thought to be related to DKT.

CONCLUSIONS

DKT could potentially inhibit diarrhea and reduce the number of bowel movements per day and the sensation of incomplete bowel evacuation after colorectal surgery. Thus, the perioperative use of DKT may be safe for colorectal cancer patients with abdominal pain and distention, who undergo surgery.

Role of single-incision laparoscopic surgery in the management of small bowel obstruction

BACKGROUND

Small bowel obstruction (SBO) arises on various backgrounds, and the surgical procedure is often modified intraoperatively as needed. Single-incision laparoscopic surgery (SILS) is less invasive than conventional multiport laparoscopic surgery (MPS) and reported to be equally safe and efficient. We have been applying SILS to SBO requiring surgical treatment, and we conducted a retrospective study to clarify the role of SILS in the management of SBO.

METHODS

Thirty-four consecutive patients were identified for inclusion in the study through a review of hospital records of patients having undergone surgery for SBO between May 2013 and June 2018. Patients with tumor- or hernia-related SBO were excluded. We also identified, for comparison, a group of patients who had undergone open surgery for SBO during the preceeding 5-year period. The primary study endpoint was the SILS completion rate, and analyses were performed to identify risk factors for conversion to open surgery and perioperative complications.

RESULTS

The SILS completion rate was 70.6% (24/34 patients), with conversion open surgery required for the remaining 10 (29.4%) patients. Conversion was necessitated by limited working space in 5 (50%) patients, discovery of massive necrosis in 3 (30%), and non-detection of the responsible lesion in 2 (20%). Univariable analysis showed an American Society of Anesthesiologists Physical Status score (p = 0.020) and severe intra-abdominal adhesions (p = 0.007) to be risk factors for conversion. Conversion to open surgery (vs complete SILS) was significantly associated with increased operation time (p = 0.018), blood loss (p = 0.021), postoperative stay (p = 0.010), and postoperative complications (p = 0.004). Open surgery was significantly associated with increased postoperative stay (p = 0.026) and postoperative complications (p = 0.011).

CONCLUSION

SILS appears to be a reasonable surgical treatment option for selected patients with SBO.

Surgical Resection of Colorectal Cancer With Distant Metastases to Other than Liver or Lung

BACKGROUND/AIM

If both distant metastases and the primary tumour of colorectal cancer (CRC) are resectable, resection of the distant metastases is considered. The aim of this retrospective study was to determine the efficacy of curative resection of both primary and metastatic lesions in organs other than liver or lung in CRC patients.

PATIENTS AND METHODS

The medical records of 23 CRC patients who received R0 resection for primary and metastatic regions between 2009 and 2018 were retrospectively analyzed.

RESULTS

The 3-year overall survival (OS) in all 23 cases was 80.0%. There was no clinicopathological factor associated with OS on univariate analysis.

CONCLUSION

Curative surgical resection appears to be useful for distant CRC metastases to organs other than liver or lung.

DS-Screen: Prospective analysis of the expression status of FGFR2 and HER2 in colorectal and gastric cancer population

431

Background: FGFR2 and HER2 proteins are well-known molecular targets for cancer therapy, and there are emerging attractive protein-targeted agents such as second generation antibody-drug conjugates. However, there are still limited information about the expression status of FGFR2 and HER2 in gastrointestinal cancer and their relationship to patient background with cancer. In this study, expression status of FGFR2 and HER2 in advanced/metastatic gastric cancer (GC) and colorectal cancer (CRC) were prospectively analyzed in clinical setting. Moreover, eligible patients for the clinical trials of DS-1123 or DS-8201, which are FGFR2- or HER2-targeting anti-cancer agent respectively, were screened. Methods: Patients with advanced/metastatic GC, gastroesophageal junctional cancer (GEJ), and CRC were enrolled. Expression status of FGFR2 and HER2 were prospectively analyzed by IHC and/or FISH. Results: A total of 565 patients (GC; 160, GEJ; 16, CRC; 389) have been enrolled in this study from November 2016 to June 2018. FGFR2 expression (IHC 1+~3+) was observed in 24%, 44%, and 3% of GC, GEJ, and CRC respectively. HER2 expression (IHC 2+, 3+) was observed in 24%, 44%, and 17% of GC, GEJ, and CRC respectively. Expression levels of FGFR2 and HER2 seemed to be not correlated with each other in all 3 types of cancer. Distributions of expression level of FGFR2 or HER2 were slightly different among the histological types in GC. In CRC, distribution of HER2 expression level was also slightly different among the histological types and HER2 expression level was higher in KRAS/NRAS wild type compared to KRAS/NRAS mutant. There was no association between HER2 expression level and primary tumor sites in patients with CRC. Slight concordance of HER2 expression was observed between IHC and FISH in CRC. A total of 7 patients have been enrolled in clinical trials of DS-1123 or DS-8201 through this study based on the analysis findings. Conclusions: This study showed insights into the expression status of FGFR2 and HER2 in GC and CRC as a large-scale prospective analysis. Seven patients who had no standard therapy could access exploratory new drug based on targetable agents through this study. Clinical trial information: 163380.

[A Case of Complete Pathological Response in a Patient with Advanced Ascending Colon Cancer That Invaded the Liver and Duodenum after FOLFOXIRI plus Bevacizumab Chemotherapy]

A 71-year-old woman with advanced ascending colon cancer was admitted to our hospital. Abdominal computed tomography( CT)revealed locally advanced sigmoid colon cancer with suspected invasion of the liver and duodenum. The clinical stage of the disease was cT4bN3M1a, cStage Ⅳa, with wild-type RAS and UGT1A1 expression. An ileostomy was performed because of bowel obstruction. The patient received 6 courses of FOLFOXIRI plus bevacizumab(Bev). The only adverse event was Grade 3 neutropenia. Laparoscopic right hemicolectomy with lymph node dissection was performed. The pathological diagnosis was the absence of viable, Grade 3 carcinoma cells. This result suggested that preoperative FOLFOXIRI plus Bev chemotherapy is useful for the treatment of locally advanced colon cancer.

[Single-Incision Laparoscopic Colectomy for Descending Colon Cancer in a Patient with a Horseshoe Kidney]

A 67-year-old woman presented with bloody stools to a local physician. Lower gastrointestinal endoscopy revealed a type 3 all-circumferential tumor at descending colon. She was diagnosed with descending colon cancer and referred to our hospital for surgery. Preoperative computed tomography(CT)revealed a horseshoe kidney. We performed single-incision laparoscopic colectomy for descending colon cancer(cT3cN0cM0, cStageⅡa)complicated by a horseshoe kidney. The surgery was performed safely without any additional injuries. In patients with horseshoe kidneys, abnormalities have been reported in the running of the blood vascular system and the renal pelvis and ureter systems. Thus, sufficient understanding of the anatomic abnormality by preoperative examinations, such as 3D-CT, is essential for performing surgery safely.

[A Case of Multidisciplinary Treatment for a Recurrent Gastrointestinal Stromal Tumor of the Stomach]

The standard treatment for unresectable or recurrent gastrointestinal stromal tumor(GIST)is tyrosine kinase inhibitor(TKI). It is reported that resection of metastatic lesions after TKI administration prolongs progression free survival, but its influence on overall survival is not clarified. We experienced a case of GIST with peritoneal dissemination for which TKI administration and 2 local resections were effective. The patient was a man in his 70's. We started chemotherapy with imatinib for GIST with peritoneal dissemination. However, it was discontinued due to the occurrence of interstitial pneumonia. Dissemination was evaluated as radically resectable on the images. After the interstitial pneumonia was alleviated, surgery was performed. Although sunitinib was introduced at 2 months postoperatively, recurrent peritoneal dissemination was detected at 32 months postoperatively, and treatment was then changed to regorafenib. Regorafenib treatment reduced the tumor size; however, Grade 3 albuminuria was detected 16 months after treatment initiation and, thus, this treatment was discontinued. Subsequently, the tumor enlarged again. Because there was only 1 recurrent lesion, we performed radical resection. Postoperatively, a reduced dose of regorafenib was re-administered. At present, 9 months after the re-surgery, the patient is alive without recurrence.

[A Case of Primary Duodenal Adenocarcinoma in the Fourth Portion]

A 66-year-old woman admitted for nausea was found to have a type 2 tumor with stenosis at the fourth portion of the duodenum by upper gastrointestinal series and endoscopy, which was diagnosed as an adenocarcinoma by endoscopic biopsy. Abdominal computed tomography(CT)showed an irregular thick wall at the fourth portion of the duodenum but without metastasis or invasion to the adjacent vessels. We examined the lymph nodes around the pancreatic head intraoperatively and partially resected the duodenum and jejunum based on the diagnosis of negative swollen nodes. The definitive diagnosis was primary tubular adenocarcinoma of the fourth portion of the duodenum, T3, N0, M0, Stage ⅡA. Reports of primary cancer of the fourth portion of the duodenum are very rare, and we include a discussion of the current literature.

c-Src promotes tumor progression through downregulation of microRNA-129-1-3p

MicroRNAs (miRNAs) fine‐tune cellular signaling by regulating expression of signaling proteins, and aberrant expression of miRNAs is observed in many cancers. The tyrosine kinase c‐Src is upregulated in various human cancers, but the molecular mechanisms underlying c‐Src‐mediated tumor progression remain unclear. In previous investigations of miRNA‐mediated control of c‐Src‐related oncogenic pathways, we identified miRNAs that were downregulated in association with c‐Src transformation and uncovered the signaling networks by predicting their target genes, which might act cooperatively to control tumor progression. Here, to further elucidate the process of cell transformation driven by c‐Src, we analyzed the expression profiles of miRNAs in a doxycycline‐inducible Src expression system. We found that miRNA (miR)‐129‐1‐3p was downregulated in the early phase of c‐Src‐induced cell transformation, and that reexpression of miR‐129‐1‐3p disrupted c‐Src‐induced cell transformation. In addition, miR‐129‐1‐3p downregulation was tightly associated with tumor progression in human colon cancer cells/tissues. Expression of miR‐129‐1‐3p in human colon cancer cells caused morphological changes and suppressed tumor growth, cell adhesion, and invasion. We also identified c‐Src and its critical substrate Fer, and c‐Yes, a member of the Src family of kinases, as novel targets of miR‐129‐1‐3p. Furthermore, we found that miR‐129‐1‐3p‐mediated regulation of c‐Src/Fer and c‐Yes is important for controlling cell adhesion and invasion. Downregulation of miR‐129‐1‐3p by early activation of c‐Src increases expression of these target genes and synergistically promotes c‐Src‐related oncogenic signaling. Thus, c‐Src‐miR‐129‐1‐3p circuits serve as critical triggers for tumor progression in many human cancers that harbor upregulation of c‐Src.

[A Case of Mesenteric Hematoma Caused by Abdominal Metastasis of Small Cell Lung Carcinoma]

Chemoradiation was performed at Osaka Police Hospital's department of respiratory medicine on a 70-year-old male with small cell lung carcinoma(cT4N3M0, cStage ⅢC). Subsequent to secondary chemotherapy for multiple bone metastases that had been observed, he received care to control the disease. He arrived at the hospital complaining of epigastric pain. He got CT-scan and was referred to our department because of a suspected hematoma around the right gastroepiploic artery. He was treated conservatively because circulatory dynamics were steady and there was no indication that anemia had progressed. However, when a test laparotomy was performed the day after the start of treatment because he presented with decreased blood pressure and progressive anemia, a massive hematoma was found around the right gastroepiploic artery. The hematoma was removed, and hemostasis was performed. Based on the pathological findings of the excised specimen, he was diagnosed with abdominal metastasis of small cell lung carcinoma. This is a report on our experience and a literature review on a case of mesenteric hematoma caused by abdominal metastasis of small cell lung carcinoma.

[A Case of Retroperitoneal Dedifferentiation Type Liposarcoma in Which Total Pancreatectomy and Radiation Therapy Was Performed at the Remnant Pancreas after Pancreaticoduodenectomy]

A 75-year-old man presented with a fever. Computed tomography revealed a 10 cm solid tumor under the duodenum. A pre-operative diagnosis of liposarcoma was established using biopsy. Pancreaticoduodenectomy was performed, and the pathological examination led to the diagnosis of dedifferentiation type liposarcoma. Two years later, the liposarcoma recurred at the remnant pancreas. A total remnant pancreatectomy was performed. The pathological examination revealed dedifferentiated type liposarcoma and positive surgical margins. Therefore, radiotherapy of 59.4 Gy in 33 fractions was performed at the recurrence area. The patient has been recurrence-free from 1 year 6 months since the second operation.

Metachronous rectal metastasis from pulmonary adenocarcinoma after 11 years of chemo-, immuno-, and radiotherapy for recurrent lesions: a case report

Background

Rectal metastasis from pulmonary adenocarcinoma is rare, and it has been regarded as an end-stage phenomenon. Recently, however, advances in lung cancer treatment have improved the chance of long-term survival of patients with unresectable distant metastases. We describe the occurrence and management of metastatic spread of a pulmonary carcinoma to the rectum.

Case presentation

The patient was a 79-year-old woman who had undergone thoracoscopic left lobectomy for pulmonary adenocarcinoma and then, over the next 11 years, various drugs (carboplatin + paclitaxel (as adjuvant therapy), gefitinib, gemcitabine + vinorelbine, S1 (an oral 5-fluorouracil-based drug), carboplatin + pemetrexed + bevacizumab, erlotinib, nivolumab, afatinib, and carboplatin+ S1) were administered, especially for hilar and mediastinal lymph node recurrences. During the eleventh postoperative year, left and right iliac bone metastases were detected, and radiation therapy was undertaken for local control of these lesions. When ¹⁸F-fluorodeoxyglucose positron emission tomography was performed for evaluation of the disease, tracer accumulation in the upper rectum was seen. Colonoscopic examination of the rectum revealed an intramural mass with central ulceration, and the mass was diagnosed histologically as an adenocarcinoma. The bone metastases appeared to be controlled, and the patient’s performance status was good, but she had suffered constipation for about a year and desired treatment. Thus, laparoscopic low anterior resection was performed. Histopathologic analysis revealed a moderately differentiated adenocarcinoma existing mainly between the submucosa and serosa, and immunohistochemical analysis showed the tumor to be positive for cytokeratin (CK) 7, negative for CK20, positive for thyroid transcription factor-1, and negative for special AT-rich sequence-binding protein 2 and caudal type homeobox 2, confirming the diagnosis of rectal metastasis from the primary pulmonary adenocarcinoma. The patient recovered well without any change in her functional status. Systemic chemotherapy was resumed, and she continues to do well, now 6 months after surgery.

Conclusions

Surgery may be a good option for the management of an isolated rectal metastasis from pulmonary cancer in patients whose functional status is good.

Abstract 401: Clinical impact of viable circulating tumor cells (v-CTC) detection and PD-L1 expression on v-CTC in the patients with resectable pancreatic cancer

[Introduction] The capture and analysis of CTCs as “liquid biopsy” provides the possibility to avoid invasive biopsies, obvious implications in cancer diagnosis and staging. We tested novel methods for viable CTCs (v-CTC) isolation in the patients (pts) with pancreatic cancer (PC), and investigated the clinical potential of v-CTCs in prognosis. We analyzed the PD-L1(L1) expression in both PC tumors and v-CTCs.

[Pts and Methods] 7.5 ml of venous blood was collected prospectively from 39 PC pts, either surgery first (S group) or pre-treatment, consisted of Gem:800mg/m2; and S-1:80mg/m2 given concurrently with IMRT to 60Gy (NACRT:N group). To detect v-CTCs, we employed a telomerase-specific replication-selective adenovirous expressing GFP. For S group, samples were obtained before/after resection. For N group, samples were obtained before/after NACRT and after resection. To distinguish between leucocyte and cells with either epithelial or mesenchymal origin, cells were stained by anti-CD45, anti-Cytokeratin and anti-Vimentin Abs. GFP-positive and CD45-negative cells were counted as v-CTC. To assess L1 expression in PC tissues (IHC) and v-CTCs, L1 IHC kit (22C3, for tissues) and anti-human L1 mAb(MIH1,for CTCs) were employed.

[Results]S group: 24 pts aged 53~85 years (male/female=12/12) were enrolled. 24 pts underwent curative resection. No v-CTCs were detected in 6 pts at both before and after resection, and 5 of 6 pts survived without recurrence. V-CTCs were identified in 18 of 24 pts, and 13 of 18 pts developed liver metastasis. Marked decrease of CTC counts were seen after resection in 10 of 18 pts, but 9 pts developed recurrence. N group: 15 PC pts aged 44~77 years (male/female=4/11) were enrolled. 15 pts underwent curative resection. No v-CTCs were detected in 5 pts, and 5 pts survived without recurrence. V-CTCs was identified in 10 of 15 pts, and only 3 out of 10 pts developed disease recurrence. Marked increase in CTC counts was observed after NACRT in 5 of 6 CTC-positive pts before NACRT, and 3 of 5 pts developed liver metastasis and died. NACRT may induce tumor cell dissemination into the blood circulation for CTC-positive pts. PD-L1 expression: L1 expression were assessed for 21 pts (S group:18, N group: 3). No patients with IHC-L1 high expression (≥50%) were observed (<1% [negative]:9, 10%:6, 20%:4, 40%:2). For S group, IHC-L1 low +/CTC-L1 + were detected in 12/18 pts (66%). IHC-L1-/CTC-L1+ were detected in 3/18 pts (17%). IHC-L1 - /no detectable CTCs were detected in 3/18 pts (17%). For N group, IHC-L1 - were detected in 3 pts, but CTCs-L1 + were detected in 2 pts (1 pt had no CTCs). The majority of detectable v-CTCs were positive for L1-expression (89% [92/103 CTCs]), despite L1-negative or -low expression in PC tissues.

[Conclusions] Viable CTC detection appears as a promising prognostic marker. Immunotherapy with anti-PD-1/PD-L1 Abs may effectively target v-CTCs.

Note: This abstract was not presented at the meeting.

Citation Format: Masahiro Tanemura, Kenta Furukawa, Manabu Mikamori, Takurou Saito, Masahisa Otsuka, Yozo Suzuki, Kentaro Kishi, Hironao Yasuoka, Masahiko Tsujimoto, Yasuo Urata, Hiroki Akamatsu. Clinical impact of viable circulating tumor cells (v-CTC) detection and PD-L1 expression on v-CTC in the patients with resectable pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 401.

A six-degree-of-freedom micro-vibration acoustic isolator for low-temperature radiation detectors based on superconducting transition-edge sensors

Dilution and adiabatic demagnetization refrigerators based on pulse tube cryocoolers are nowadays used in many low temperature physics experiments, such as atomic force and scanning tunneling microscopy, quantum computing, radiation detectors, and many others. A pulse tube refrigerator greatly simplifies the laboratory activities being a cryogen-free system. The major disadvantage of a pulse tube cooler is the high level of mechanical vibrations at the warm and cold interfaces that could substantially affect the performance of very sensitive cryogenic instruments. In this paper, we describe the performance of a very simple mechanical attenuation system used to eliminate the pulse-tube-induced low frequency noise of the superconducting transition-edge sensors under development for the instruments of the next generation of infra-red and X-ray space observatories.

[A Case of Myeloid Sarcoma That Primarily Developed in the Spleen]

We report a case of myeloid sarcoma(MS)that primarily developed in the spleen. The patient was a 60s man with a chief complainant of low-grade fever following a dental implant. Although he underwent intensive antibiotic treatment, including levofloxacin, meropenem, and vancomycin, no significant decline in fever was observed. Abdominal contrast-enhanced CT revealed an LDA occupying the majority of his spleen, which was diagnosed as a splenic abscess. Although a CT-guided biopsy and drainage for the spleen were considered, a puncture of the spleen was not performed due to the substantial concern of bleeding. Subsequently, a splenectomy was performed and HE staining revealed mitosis of tumor cells and massive necrosis. Immunohistochemical analysis revealed that the tumor cells were positive for myeloperoxidase, CD43, CD45, and CD68. Finally, the splenic LDA was diagnosed as MS instead of a splenic abscess. He was treated with systemic chemotherapy. MS primarily develops in the spleen is quite rare: we found only 2 case reports of this disease. The prognosis of MS is poor due to the complications of AML. Accordingly, MS should be considered as a differential diagnosis for accurate diagnosis and treatment of splenic LDA.

[A Case of Cecal Cancer in a Patient with Situs Inversus Treated with Single-Port Laparoscopic Surgery]

A 67-year-old woman who had been treated for cardiac sarcoidosis was diagnosed with cecal cancer by detailed examination. Although an anatomical abnormality was present, we determined that a curative operation with single-port laparoscopic surgery(SILS)was feasible. We safely performed ileocecal resection with D3 lymph node dissection(operative time of 91 min with almost no intraoperative blood loss), and the patient developed no operation-related complications during the postoperative course. Although cecal cancer with situs inversus is very rare, SILS is thought to be safe and feasible when performed by surgeons, who are familiar with the SILS technique and the spatial-cognitive features of situs inversus.

[A Comparative Study on Feasibility of SOX Therapy and SP Therapy with Short Hydration for Gastric Cancer in the Outpatient Setting]

We conducted a retrospective comparative study on feasibility of S-1/oxaliplatin(SOX)therapy and S-1/cisplatin therapy with short hydration(SP-SH)for gastric cancer in the outpatient setting. The subjects were patients with gastric cancer aged younger than 75 years who underwent SOX or SP-SH therapy at our hospital. There were 22 patients in the SOX group and 30 patients in the SP-SH group. Both the groups received the first course during hospitalization and then received the subsequent courses in the outpatient section. Evaluation items for each therapy included the treatment rate in the outpatient setting, number of re-hospitalization cases, relative dose intensity(RDI), and adverse events. The treatment rate in the outpatient setting was 100%(22/22)in the SOX group and 96%in the SP-SH group(26/27). Re-hospitalization cases included 1 case of loss of appetite in the SOX group and 1 cases of loss of appetite and 2 cases of febrile neutropenia(FN)in the SP-SH group. The median values of the RDI were 86% with S-1 and 85% with oxaliplatin in the SOX group and 92% with S-1 and 80% with cisplatin in the SP-SH group. The SP-SH group had a higher proportion of neutropenia cases of Grade 3 or higher(SP-SH 33% v. s SOX 5%, p=0.012). The SOX group showed a higher proportion of loss of appetite cases for all the Grades(SOX 86% v. s SP-SH 50%, p=0.007)and peripheral neuropathy cases(SOX 64% v. s SP-SH 23%, p=0.003). It was considered that SOX and SP-SH therapies can be treated in the outpatient section, although the occurrence of loss of appetite and FN must be considered.