Monitoring ctDNA RAS Mutational Status in Metastatic Colorectal Cancer: A Trial Protocol of RAS-trace and RAS-trace-2 Studies

Background

Spatial and temporal heterogeneities of RAS and other molecular genes should be considered in the treatment of metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs); acquired RAS mutation is sometimes observed at disease progression of treatment with the anti-EGFR mAb. At the same time, discrepancy of RAS status from tissues and circulating tumor DNA (ctDNA) in the same patient is sometimes observed. Based on this, we commenced two observational studies to clarify these heterogeneities of RAS and BRAF in mCRC, using next generation sequencing from liquid biopsy.

Methods/Design

RAS-trace study is an observational study to monitor ctDNA RAS/BRAF/PIK3CA status every 4-12 weeks using the Plasma-SeqSensei™ CRC RUO Kit (Sysmex Inostics GmbH) in mCRC with RAS/BRAF wild-type (wt) on tumor tissue. The primary endpoint was the time to the acquired RAS mutations. A total of 42 patients has been accrued. RAS-trace-2 study is also an observational study aimed at comparing the efficacy of the anti-EGFR mAb in ctDNA RAS/BRAF wt with ctDNA RAS or BRAF mutant mCRC patients, whose RAS/BRAF are wt in tumor tissue. The primary endpoint was progression-free survival in patients with ctDNA RAS/BRAF wt and RAS or BRAF mutant. A total of 240 patients will be accrued over 2 years.

Discussion

These trials will help us understanding the clinical significance of spatial and temporal heterogeneities of RAS, BRAF and other genes, while optimizing the anti-EGFR mAb treatment strategies in mCRC.

Two Surgical Cases of Colorectal Cancer in Patients With Immunoglobulin G4-Related Disease

Immunoglobulin G4-related disease (IgG4RD) is a relatively new disease concept that is most common in Asia. It is a systemic chronic lymphoproliferative disease that is diagnosed by mass formation or thickened lesion, a high serum IgG4 level (≥135 mg/dL), and confirmation of lymphocytes and plasma cells by histopathological examination. The precise mechanism of this disease remains elusive; however, distinguishing IgG4RD from malignancy proves challenging due to its manifestation of swollen lymph nodes and retroperitoneal thickening and fibrosis. Malignancy is also 3.5 times more likely in cases with IgG4RD. In this study, we report two cases of colorectal cancer in patients with IgG4RD who underwent surgery. In both cases, excising the tumor from the retroperitoneal posed a challenge, and swollen lymph nodes were observed without evidence of cancer metastasis. We believe that these are very informative cases, and we report the cases with a literature review of IgG4RD.

A pilot study on the safety and efficacy of neoadjuvant chemo‑adoptive immunotherapy for locally advanced rectal cancer

The safety and efficacy of combination therapy of immune cell therapy and chemotherapy [chemo-adoptive immunotherapy (CAIT)] for patients with stage IV or recurrent colorectal cancer have been reported. In the present study, the safety and efficacy of neoadjuvant CAIT were investigated for preoperative therapy of locally advanced rectal cancer. The study included patients with cT3/T4 or cN (+) rectal adenocarcinoma scheduled for curative surgery. Six patients who consented to participate in the current study were selected as subjects. Neoadjuvant CAIT involves administration of activated autologous lymphocytes, αβ T cells, and mFOLFOX6 every 2 weeks for six courses, followed by surgery 4-6 weeks thereafter. Common Terminology Criteria for Adverse Events grade 3 neutropenia was observed in one patient. Neoadjuvant CAIT and curative surgery were performed on all the patients. The confirmed response rate was 67%. Downstaging was confirmed in five patients (83%). Regarding histological effects, two patients were grade 1a and four were grade 2. Regarding immunological reactions, both CD4+ and CD8+ T cell infiltration rates increased after treatment in three patients on tumor-infiltrating lymphocyte (TIL) analysis. In peripheral blood analysis, the total lymphocyte count was maintained in all patients, and the CD8+ T cell count increased by ≥3 times on the pretreatment count in two patients but may not be associated with changes in TILs. During the median postoperative follow-up duration of 24 months, liver and lung metastases occurred in one patient, but all patients survived. In conclusion, neoadjuvant CAIT (αβ T cells + mFOLFOX6) can be safely administered for the treatment of advanced rectal cancer. Verification of the efficacy of comprehensive immune cell therapy, especially the induction of antitumor immunity for the prevention of recurrence, will be maintained. The current study is registered with the Japan Registry of Clinical Trials (jRCT; ID, jRCTc030190248; January 21, 2019).

Relationship between age-related changes in mandibular third molar roots and the possibility of mental nerve paresthesia after tooth extraction

Mental nerve paresthesia is a serious postoperative complication of mandibular third molar extraction. It appears that no study has examined the relationship between the surface morphology of the mandibular third molar roots and the possibility of mental nerve paresthesia following tooth extraction. Therefore, the root morphology of the mandibular third molars was examined according to age using dental cone beam computed tomography (CBCT), and the possibility of mental nerve paresthesia following tooth extraction was evaluated. The study included 1216 patients who had undergone mandibular third molar extractions. The root morphology of 1534 teeth in 791 patients who had CBCT performed before surgery was studied. Factors evaluated were age, complete or incomplete formation of the mandibular third molar roots, periodontal ligament atrophy of the mandibular third molar roots, hypercementosis, and mandibular canal deformation. Mandibular third molar root formation was completed between the ages of 19 and 30 years. Complete formation of the mandibular third molar roots (P = 0.002) and deformation of the mandibular canal (P < 0.001) were identified as risk factors for mental nerve paresthesia. These findings suggest that the risk of mental nerve paresthesia could be reduced if the extraction of third molars is performed prior to complete root formation.

NTRK2 expression in gastrointestinal stromal tumors with a special emphasis on the clinicopathological and prognostic impacts

Gastrointestinal stromal tumors (GISTs) are typically characterized by activating mutations of the KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA). Recently, the neurotrophic tyrosine receptor kinase (NTRK) fusion was reported in a small subset of wild-type GIST. We examined trk IHC and NTRK gene expressions in GIST. Pan-trk immunohistochemistry (IHC) was positive in 25 (all 16 duodenal and 9 out of 16 small intestinal GISTs) of 139 cases, and all pan-trk positive cases showed diffuse and strong expression of c-kit. Interestingly, all of these cases showed only trkB but not trkA/trkC expression. Cap analysis of gene expression (CAGE) analysis identified increased number of genes whose promoters were activated in pan-trk/trkB positive GISTs. Imbalanced expression of NTRK2, which suggests the presence of NTRK2 fusion, was not observed in any of trkB positive GISTs, despite higher mRNA expression. TrkB expression was found in duodenal GISTs and more than half of small intestinal GISTs, and this subset of cases showed poor prognosis. However, there was not clear difference in clinical outcomes according to the trkB expression status in small intestinal GISTs. These findings may provide a possible hypothesis for trkB overexpression contributing to the tumorigenesis and aggressive clinical outcome in GISTs of duodenal origin.

Tyrosine kinase alterations in colorectal cancer with emphasis on the distinct clinicopathological characteristics

AIMS

Tyrosine kinase (TK) alterations, such as anaplastic lymphoma kinase (ALK) fusion, neurotrophic tyrosine receptor kinase (NTRK) fusion, c-ros oncogene 1 (ROS1) fusion and mesenchymal-epithelial transition factor (MET) exon 14 skipping, have been reported in colorectal cancers (CRC). We have previously reported CRCs with NTRK fusion among our cohort. However, their clinicopathological features have not been fully elucidated.

METHODS AND RESULTS

Tissue microarray (TMA)-based immunohistochemistry (IHC) was performed on 951 CRC lesions from 944 patients. IHC was evaluated as positive or negative for ALK and ROS1 and 0 to 3+ for c-MET. For ALK and ROS1 IHC-positive cases, RNA-based imbalanced gene expression assays, Archer FusionPlex assays and reverse transcription-polymerase chain reaction (RT-PCR) followed by Sanger sequencing were performed. For c-MET IHC 3+ cases, RT-PCR followed by Sanger sequencing were performed. ALK IHC was positive in three cases (0.2%) and all showed imbalanced ALK gene expression. The following ALK fusions were confirmed: EML4 (exon 21)::ALK (exon 20), EML4 (exon 6)::ALK (exon 19) and HMBOX1 (exon 6)::ALK (exon 20). Two showed microsatellite instability-high/mismatch repair (MMR)-deficient, and all were located in the right colon. ROS1 IHC was positive in one case; however, imbalanced expression and ROS1 fusion was negative. Forty-two cases (4.4%) showed c-MET IHC3+. MET exon 14 skipping was confirmed in nine cases. All cases were microsatellite stable/MMR-proficient, and eight were located in the left colon and rectum.

CONCLUSIONS

CRCs with these TK alterations had distinct clinicopathological features. Together with our previous study, 15 cases (1.6%) harboured targetable TK alterations (three NTRK fusion, three ALK fusion, nine MET exon 14 skipping).

Prognostic factors in patients with high-risk stage II colon cancer after curative resection: a post hoc analysis of the JFMC46-1201 trial

PURPOSE

The goal of the current study was to identify prognostic factors for disease-free survival (DFS) and overall survival (OS) in high-risk stage II colon cancer.

METHODS

The subjects were patients with histologically confirmed stage II colon cancer undergoing R0 resection who met at least one of the following criteria: T4, perforation/penetration, poorly differentiated adenocarcinoma, mucinous carcinoma, and < 12 examined lymph nodes. Patients self-selected surgery alone or a 6-month oral uracil and tegafur plus leucovorin (UFT/LV) regimen. Serum CEA mRNA at ≥ 24 h after surgery and < 2 weeks after registration was also examined as a potential prognostic factor for stage II colon cancer. This study is registered with UMIN-CTR (protocol ID: UMIN000007783).

RESULTS

1880 were included in the analysis to identify prognostic factors for DFS and OS in patients with high-risk stage II colon cancer. In multivariate analyses, gender, depth of tumor invasion, extent of lymph node dissection, number of examined lymph nodes, and postoperative adjuvant chemotherapy (POAC) emerged as significant independent prognostic factors for DFS. Similarly, multivariate analysis showed that age, gender, depth of tumor invasion, perforation/penetration, extent of lymph node dissection, number of examined lymph nodes, and POAC were significant independent prognostic factors for OS. Univariate analyses showed no significant difference in DFS or OS for CEA mRNA-positive and mRNA-negative cases.

CONCLUSION

This study showed that gender, depth of tumor invasion, extent of lymph node dissection, number of examined lymph nodes, and lack of use of POAC were significant independent prognostic factors in stage II colon cancer.

The methylation level of a single cancer risk marker gene reflects methylation burden in gastric mucosa

BACKGROUND

Gastric cancer risk can be accurately predicted by measuring the methylation level of a single marker gene in gastric mucosa. However, the mechanism is still uncertain. We hypothesized that the methylation level measured reflects methylation alterations in the entire genome (methylation burden), induced by Helicobacter pylori (H. pylori) infection, and thus cancer risk.

METHODS

Gastric mucosa of 15 healthy volunteers without H. pylori infection (G1), 98 people with atrophic gastritis (G2), and 133 patients with gastric cancer (G3) after H. pylori eradication were collected. Methylation burden of an individual was obtained by microarray analysis as an inverse of the correlation coefficient between the methylation levels of 265,552 genomic regions in the person's gastric mucosa and those in an entirely healthy mucosa.

RESULTS

The methylation burden significantly increased in the order of G1 (n = 4), G2 (n = 18), and G3 (n = 19) and was well correlated with the methylation level of a single marker gene (r = 0.91 for miR124a-3). The average methylation levels of nine driver genes tended to increase according to the risk levels (P = 0.08 between G2 vs G3) and was also correlated with the methylation level of a single marker gene (r = 0.94). Analysis of more samples (14 G1, 97 G2, and 131 G3 samples) yielded significant increases of the average methylation levels between risk groups.

CONCLUSIONS

The methylation level of a single marker gene reflects the methylation burden, which includes driver gene methylation, and thus accurately predicts cancer risk.

Risk factors for small-bowel obstruction after colectomy for colorectal cancer: a retrospective study

PURPOSE

Postoperative adhesions are a concerning complication of abdominal surgery with major implications on quality of life. This study aimed to investigate the risk factors for postoperative small-bowel obstruction (SBO) after colectomy for colorectal cancer.

METHODS

We reviewed the clinicopathological variables of 1646 patients who underwent colectomy for colorectal cancer between 2009 and 2018.

RESULTS

SBO occurred following primary tumor resection for colorectal cancer in 67 (4.1%) of the 1646 patients. The median observation period was 7.5 (range: 3.0-12.0) years. Multivariate analysis revealed that rectal tumors, anastomotic leakages, previous abdominal surgeries, and longer operating times were all correlated with postoperative SBO, but there were no differences in the incidence of SBO between laparoscopic vs. open surgery. The use of adhesion prevention material had no effect on SBO. Our data showed that the onset of SBO tended to be relatively early, within a year after surgery (89.5%).

CONCLUSIONS

Tumor localization in the rectum is associated with several problems, including a wide resection area, prolonged operative duration, and high risk of anastomotic leakage, which may increase the risk of SBO. Laparoscopic surgery and adhesion prevention material did not demonstrate a clear preventive effect against SBO.

Positron Generation and Acceleration in a Self-Organized Photon Collider Enabled by an Ultraintense Laser Pulse

We discovered a simple regime where a near-critical plasma irradiated by a laser of experimentally available intensity can self-organize to produce positrons and accelerate them to ultrarelativistic energies. The laser pulse piles up electrons at its leading edge, producing a strong longitudinal plasma electric field. The field creates a moving gamma-ray collider that generates positrons via the linear Breit-Wheeler process-annihilation of two gamma rays into an electron-positron pair. At the same time, the plasma field, rather than the laser, serves as an accelerator for the positrons. The discovery of positron acceleration was enabled by a first-of-its-kind kinetic simulation that generates pairs via photon-photon collisions. Using available laser intensities of 10^{22}  W/cm^{2}, the discovered regime can generate a GeV positron beam with a divergence angle of around 10° and a total charge of 0.1 pC. The result paves the way to experimental observation of the linear Breit-Wheeler process and to applications requiring positron beams.

Positive Circumferential Resection Margin in Rectal Cancer Is a Robust Predictor of Poor Long-term Prognosis With Clinicopathological Bias Between Groups Compensated by Propensity-score Matching Analysis

BACKGROUND/AIM

Circumferential resection margin (CRM) is the most reliable predictor of local and distant recurrence in locally-advanced rectal cancer (LARC). The present study was conducted to compare the long-term outcomes between CRM (+) and (-) groups using propensity-score (PS) matching analysis to compensate for bias between groups.

PATIENTS AND METHODS

Of 563 consecutive patients with Stage II/III rectal cancer who were treated surgically with curative-intent at Juntendo University Hospital between Jan 1989 and Mar 2018, 412 patients were enrolled retrospectively in the study. The patients were divided into a CRM (+) group (n=21; 5.1%) and a CRM (-) group (n=391; 94.9%).

RESULTS

In the entire cohort, recurrence-free survival (RFS), local recurrence-free survival (LRFS), non-local recurrence-free survival (NLRFS), and cancer-specific survival (CSS) were significantly worse among patients in the CRM (+) group compared with those in the CRM (-) group. Univariate analysis demonstrated patients in the CRM (+) group had significantly larger primary tumors (p=0.02), more frequently had open surgery (p=0.009), had an abdominoperineal resection (APR) procedure (p=0.01) and a T4 primary tumor (p<0.0001). After PS matching analysis, in the propensity-matched cohort, RFS, LRFS, NLRFS and CSS were significantly worse among patients in the CRM (+) group compared with those in the CRM (-) group.

CONCLUSION

PS matching analysis demonstrated that RFS, LRFS, NLRFS, and CSS were significantly worse among patients in the CRM (+) group compared with those in the CRM (-) group. The present results indicate that CRM (+) is a robust predictor of long-term outcome of LARC, independent of tumor size.

[A Case of Cecum Cancer with Lymph Node Metastasis and Invasion in the Superior Mesenteric Vein Treated with Combined SMV Resection and Reconstruction]

The patient was a 77-year-old woman. She visited her family doctor with a complaint of bloody stools, and was pointed out a Type 3 colon cancer in the cecum with a colonoscopy. In addition, an enlarged lymph node(#203)was found on the right side of the superior mesenteric vein(SMV). Laparoscopic surgery was initiated, and when the patient was moved to vascular processing, a firm adhesion of the lymph node(#203)was observed on the right side of the SMV. A small laparotomy was added, and a partial combined resection of the SMV was performed en bloc to complete the ileal resection. Histopathological findings showed T4b(transverse colon)N3M0, pStage Ⅲc, and metastatic lymph node(#203)showed evidence of invasion to the SMV. Adjuvant chemotherapy was administered, but lung metastases appeared 4 months and liver metastasis appeared 29 months after surgery. The patient was transferred to a different hospital for best supportive care(BSC)at 34 months after surgery.

Examination of colorectal cancer cases with metal allergy

PURPOSE

To report our initiatives and treatment results for patients with colorectal cancer with metal allergy.

METHODS

A total of 27 patients (2.6%) with a history of metal contact dermatitis were identified among 1027 patients who underwent curative resection of colorectal cancer from 2014 to 2020. The results of the patch test, perioperative results, and postoperative colonoscopy findings were also investigated.

RESULTS

The patch test for metal allergens and staples was performed in 21 patients (77.8%), and 13 of them (61.9%) tested positive for at least one metal allergen. Ni (38.1%), Co (28.6%), and Pd (19.0%) showed higher positive rates than other metals, and 1 patient (4.8%) tested positive for staples. Stapled anastomosis/suturing was performed as planned in 15 of 27 patients. In 10 patients, the anastomosis method was changed from stapled to hand-sewn according to the no-patch test results (60%), positivity for multiple metals (20%), positivity for staples (10%), and surgeon's judgment (10%). No complications and abnormal colonoscopy findings were found to be associated with stapled anastomosis/suturing.

CONCLUSION

The patch test is useful for selecting an optimal anastomosis method for patients with suspected metal allergy.

Local recurrence of submucosal invasive colorectal cancer after endoscopic submucosal dissection revealed by copy number variation

We report a case in which analysis of copy number variation revealed local recurrence of submucosal invasive colorectal cancer after curative endoscopic submucosal dissection (ESD). An 86-year-old man with a history of abdominoperineal resection of the rectum for rectal cancer underwent resection with ESD for early-stage sigmoid cancer 5 cm away from the stoma opening. At the same time, ileocecal resection was performed for advanced cecal cancer. Twelve months after ESD, advanced cancer occurred in the area of the ESD lesion. It was unclear if the cancer was a local recurrence after ESD, implantation of cecal cancer, or a new lesion. Copy number variation analysis performed for the three lesions revealed that the new lesion originated from residual tumor cells from ESD and was unlikely to be cecal cancer.

Evaluation of the Safety and Efficacy of Modified Laparoscopic Suture Rectopexy for Rectal Prolapse

Objectives

There are many surgical options for the treatment of rectal prolapse. To date, the efficacy of mesh-free laparoscopic suture rectopexy remains unclear due to the limited number of reports. This study aimed to evaluate the safety and efficacy of laparoscopic suture rectopexy.

Methods

This observational cohort study is a retrospective cross-sectional analysis of a continuously maintained database. All patients underwent laparoscopic suture rectopexy for rectal prolapse between April 2012 and March 2018. The primary outcomes measured were recurrence rates and complications of laparoscopic suture rectopexy.

Results

A total of 268 patients (29 male and 239 female) underwent laparoscopic suture rectopexy. Their mean age was 77 (19-95) years, and the mean prolapse length was 6.4 (3.5-20) cm. One patient suffered an intraabdominal abscess. Spondylitis developed in another patient following surgery. The median follow-up period was 45 (12-82) months. A total of 22 patients (8.2%) developed recurrence. The average time to recurrence was 15.6 (1-44) months. Multivariate analysis revealed a significant correlation between recurrence and prolapse length >7.0 cm (OR: 1.26, 95% CI: 1.38-1.42, P < 0.01).

Conclusions

Laparoscopic suture rectopexy for complete rectal prolapse is a minimally invasive and safe procedure that may lead to lower recurrence rates.

Benefits and risks of diverting stoma creation during rectal cancer surgery

Purpose

A consensus has been reached regarding diverting stoma (DS) construction in rectal cancer surgery to avoid reoperation related to anastomotic leakage. However, the incidence of stoma-related complications (SRCs) remains high. In this study, we examined the perioperative outcomes of DS construction in patients who underwent sphincter-preserving surgery for rectal cancer.

Methods

We included 400 participants who underwent radical sphincter-preserving surgery for rectal cancer between 2005 and 2017. These participants were divided into the DS (+) and DS (-) groups, and the outcomes, including postoperative complications, were compared.

Results

The incidence of ileus was higher in the DS (+) group than in the DS (-) group (P<0.01); however, no patients in the DS (+) group showed grade 3 anastomotic leakage. Furthermore, early SRCs were observed in 33 patients (21.6%) and bowel obstruction-related stoma outlet syndrome occurred in 19 patients (12.4%). There was no significant intergroup difference in the incidence of grade 3b postoperative complications. However, the most common reason for reoperation was different in the 2 groups: anastomotic leakage in 91.7% of patients with grade 3b postoperative complications in the DS (-) group, and SRCs in 85.7% of patients with grade 3b postoperative complications in the DS (+) group.

Conclusion

Patients with DS showed higher incidence rates of overall postoperative complications, severe postoperative complications (grade 3), and bowel obstruction, including stoma outlet syndrome, than patients without DS. Therefore, it is important to construct an appropriate DS to avoid SRCs and to be more selective in assigning patients for DS construction.

[A Case of Recurrence in the Abdominal Wall and Perineal Region of Rectal Cancer Successfully Treated with Minimally Invasive Surgery and Radiation Therapy]

Local recurrence after rectal cancer surgery is often difficult to treat because there are few effective treatments. In this study, we report a case of parastomal and perineal recurrence after Miles' surgery in an elderly patient who had a favorable outcome after laparoscopic surgery and radiation therapy. Our results suggest that a combination of minimally invasive treatment may be effective in elderly patients and after polysurgery.

[A Case Report of a Giant GIST Markedly Responsive to Neoadjuvant Chemotherapy with Imatinib Mesylate]

Male in his 50s complaining of abdominal pain was referred to our hospital. Abdominal CT scan showed a giant tumor which had diameter of approximately 50 mm in lower rectum. A biopsy specimen was positive for CD34 and c-kit. Based on these findings, it was diagnosed as gastrointestinal stromal tumor(GIST). We treated the patient with neoadjuvant therapy using imatinib mesylate(IM)to reduce the tumor size and to avoid the extensive surgery. The patient started to take IM at a daily dose of 400 mg. After 3 months, CT and MRI revealed that the tumor size decreased(40% reduction). We performed the robot assisted intersphincteric resection(ISR). Although it has been 28 months since the surgery, there are no obvious signs of recurrence. A patient diagnosed with giant GIST could avoid an extensive surgery due to neoadjuvant therapy with IM.

Efficacy and safety of regorafenib dose-escalation therapy for Japanese patients with refractory metastatic colorectal cancer (RECC study)

BACKGROUND

Regorafenib significantly improves overall survival in previously treated metastatic colorectal cancer patients. However, various toxicities, such as hand-foot skin reaction (HFSR), fatigue, and liver dysfunction have limited the use of regorafenib. These toxicities appear soon after treatment initiation. The ReDOS study demonstrated the effectiveness of a weekly dose-escalation therapy of regorafenib starting with a lower daily dose; however, its usefulness in Asian subjects is unknown. We conducted a phase II study to evaluate the safety and survival benefit of regorafenib dose-escalation therapy for Japanese patients.

METHODS

Patients with sufficient organ function, who had previously received more than two lines of chemotherapy were included. Regorafenib was started at 80 mg/day and escalated to 120 mg/day in Week 2 and 160 mg/day in Week 3, if no severe drug-related toxicities were observed. The primary endpoint was cancer progression-free survival (PFS). Tumor response and progression were assessed radiologically every 8 weeks. This study was registered in the University Hospital Medical Information Network (UMIN#UMIN000028933).

RESULTS

57 patients were enrolled and all started regorafenib at 80 mg/day. 32 patients (56.1%) were subsequently escalated to 120 mg/day and 19 (33.3%) to 160 mg/day. Only 8 patients (14.0%) discontinued treatment because of adverse events. Median PFS was 1.9 months. Median overall survival was 8.9 months, the response rate was 0%, and the disease control rate was 31.6%. The most frequent adverse event greater than grade 3 was hypertension (19.3%), followed by HFSR (14.0%).

CONCLUSIONS

Regorafenib dose-escalation therapy is well tolerated with PFS-like regorafenib standard therapy.

[A Case Report for Peritoneal Recurrences by Laparoscopic Surgery after Colorectal Cancer Resection]

We report a cases report of colorectal cancer who underwent repeated resection for peritoneal recurrences by laparoscopic surgery. In 2013, a 70-year-old woman diagnosed with an ascending colon cancer underwent laparoscopic right hemicolectomy. The pathological diagnosis was tub2, pT4aN1M0, Stage Ⅲb. Postoperative adjuvant chemotherapy(uracil and tegafur/Leucovorin)was administered. PET-CT performed at 25 months after the surgery because of CEA elevation. It revealed a peritoneal recurrence in the pouch of Douglas. The following peritoneal recurrences were removed by laparoscopic Hartmann's procedure. Chemotherapy(5-fluorouracil/levofolinate/oxaliplatin/bevacizumab)was administered 11 courses and after that chemotherapy(5-fluorouracil/levofolinate/bevacizumab)was administered 6 courses. PET-CT performed 37 months after the second surgery revealed a peritoneal recurrence near the right ovary in the pouch of Douglas. The following peritoneal recurrences was removed. Chemotherapy(tegafur/gimeracil/oteracil/bevacizumab)was administered 11 courses. The long-term survival has been continued for 7 years and 7 months after first operation. It was considered that laparoscopic surgery for peritoneal recurrence in colorectal cancer is contributed to one of the surgical procedures in selected patients.

CHFR-Promoter-Methylation Status Is Predictive of Response to Irinotecan-based Systemic Chemotherapy in Advanced Colorectal Cancer

BACKGROUND/AIM

We investigated whether promoter methylation of the checkpoint-with-forkhead-and-ring-finger-domains (CHFR) gene is a predictor of the efficacy of irinotecan-based systemic chemotherapy for advanced colorectal cancer (CRC) patients.

MATERIALS AND METHODS

CHFR-promoter methylation was measured by quantitative methylation-specific PCR (qMSP). The histoculture drug response assay (HDRA) was used in vitro to analyze the correlation between CHFR-promoter methylation and the efficacy of the irinotecan-active-metabolite SN38 in colorectal-cancer tissues from 44 CRC patients. CHFR promoter-methylation was also analyzed for its correlation with clinical response to irinotecan-based systemic chemotherapy of 49 CRC patients.

RESULTS

CHFR-promoter methylation significantly-positively correlated with inhibition of colon cancer by SN38 in the HDRA (p=0.002). CHFR-promoter methylation also significantly-positively correlated with clinical response to irinotecan-based systemic chemotherapy (p=0.04 for disease control). CHFR-promoter methylation also significantly-positively correlated (p=0.01) with increased progression-free survival for patients treated with irinotecan-containing FLOFIRI in combination with bevacizumab, the most-frequent regimen in the cohort.

CONCLUSION

Sensitivity of advanced CRC patients to irinotecan-based systemic chemotherapy can be predicted by the extent of CHFR-promoter methylation.

[Management of a perforated duodenal diverticulum using an endoscopic nasobiliary drainage tube:a case report]

A man in his 70s visited our hospital for abdominal pain. Upon admission, abdominal computed tomography findings suggested a duodenal diverticular perforation. Upper gastrointestinal endoscopy revealed an incarcerated enterolith in the periampullary diverticulum. We achieved conservative management by inserting an endoscopic nasobiliary drainage tube into the duodenal diverticulum to aid drainage. The patient was discharged without serious complications 35 days after admission. We report a case of duodenal diverticular perforation with an incarcerated enterolith managed conservatively using endoscopic therapy.

Laparoscopic Surgery Is Acceptable for Elderly Patients With Colorectal Cancer: A Propensity Score-matched Study

BACKGROUND/AIM

The study was performed to examine the suitability of laparoscopic surgery for elderly patients with colorectal cancer.

PATIENTS AND METHODS

The subjects were 242 patients aged ≥80 years who underwent primary tumor resection of colorectal cancer using laparoscopic assisted colectomy (LAC, n=145) or open colectomy (OC, n=97). Propensity score matching used to balance the characteristics of the groups resulted in 76 patients being assigned to each group.

RESULTS

Before matching, Glasgow Prognostic Score (GPS), American Society of Anesthesiologists physical status (ASA-PS), and previous abdominal surgery differed significantly between the groups (p<0.05), but after matching, all covariates were balanced (p≥0.05). Short-term outcomes were better after LAC (p<0.05), including fewer postoperative complications and less delirium. Regarding long-term outcomes, 5-year overall survival did not differ significantly between the groups (p=0.91).

CONCLUSION

In elderly patients with colorectal cancer, short-term results are better after LAC than OC and long-term results are similar. These findings indicate that LAC is acceptable in this patient population.

Rectal metastasis from bladder urothelial carcinoma: a case report

Background

Urothelial carcinoma arises from transitional cells in the urothelial tract. In advanced cases, it can metastasize locally to surrounding organs or distally to organs such as the lungs, bones, or liver. Here we describe a case of rectal metastasis from urothelial carcinoma treated with multiple sessions of transurethral resection of bladder tumor (TURBT).

Case presentation

A 72-year-old woman presented to our department with abdominal bloating andobstructed defecation. She had undergone two sessions of TURBT for early urothelial carcinoma in another hospital at 64 and 65 months ago, respectively. Cystoscopy at 3 months after the second TURBT session had indicated disease recurrence, and thus, she had been referred to our hospital for further examination, followed by TURBT for the third time at 59 months ago and for the fourth time at 48 months ago; thereafter, she had been followed up with cystoscopy every 6 months without any recurrence. However, she returned to our hospital, complaining of difficult defecation. Subsequent colonoscopy demonstrated an obstructive tumor in the rectum, which was pathologically diagnosed as metastatic urothelial carcinoma of the bladder. Laparoscopic examination revealed two small areas of peritoneal dissemination in the pelvis. A sigmoid colostomy was performed without rectal tumor resection. She has been receiving chemotherapy and is still alive 10 months after surgery.

Conclusions

Rectal metastasis is a rare site of metastasis for urothelial carcinomas. It is important to consider the possibility of annular rectal constriction caused by infiltrating or metastasizing urothelial carcinoma when managing patients with urothelial carcinoma and with difficult defecation.

A case of simultaneous abdominal wall metastasis of hepatocellular carcinoma with long-term relapse-free survival after laparoscopic resection

We report our experience of an extremely rare case of a simultaneous extrahepatic metastasis of hepatocellular carcinoma (HCC) with long-term relapse-free survival, treated by laparoscopic resection of an abdominal wall tumor and subsequent radiofrequency ablation (RFA) of an intrahepatic lesion. A 76-year-old man visited a local clinic for right lower abdominal pain. He was treated with antibiotics and the symptom resolved. However, a mass was detected in the same region and he was referred to our hospital for further evaluation. Computed tomography (CT) of the abdomen showed a mass 5 cm in diameter, raising suspicions of an intra-abdominal tumor. Laparoscopic surgery was performed, and the tumor was found in the abdominal wall and completely resected. Histopathological examination yielded a diagnosis of extrahepatic HCC. Post-operative positron emission tomography (PET)-CT showed increased uptake of fluorodeoxyglucose in segment 3 (S3) of the liver. On performing a liver biopsy, HCC was diagnosed. Subsequently, the S3 lesion was treated with radiofrequency ablation. The patient has remained relapse-free for 6 years without further treatments.

Significance of postoperative adjuvant chemotherapy with an oxaliplatin-based regimen after simultaneous curative resection for colorectal cancer and synchronous colorectal liver metastasis: a propensity score matching analysis

Background

Expansion of the indication for liver resection and new regimens for systemic chemotherapy have improved postoperative outcomes for synchronous colorectal liver metastases (CRLM). However, such cases can still have a high recurrence rate, even after curative resection. Therefore, there is a need for postoperative adjuvant chemotherapy (POAC) after liver resection in patients with CRLM. There are few studies of the efficacy of POAC with an oxaliplatin-based regimen after simultaneous resection for colorectal cancer and CRLM with curative intent. The goal of the study was to compare POAC with oxaliplatin-based and fluoropyrimidine regimens using propensity score (PS) matching analysis.

Methods

The subjects were 94 patients who received POAC after simultaneous resection for colorectal cancer and synchronous CRLM, and were enrolled retrospectively. The patients were placed in a L-OHP (+) group (POAC with an oxaliplatin-based regimen, n = 47) and a L-OHP (−) group (POAC with a fluoropyrimidine regimen, n = 47). Recurrence-free (RFS), cancer-specific (CSS), unresectable recurrence-free (URRFS), remnant liver recurrence-free (RLRFS), and extrahepatic recurrence-free (EHRFS) survival were analyzed.

Results

Before PS matching, the L-OHP (+) and (−) groups had no significant differences in RFS, CSS, URRFS, RLRFS, and EHRFS. Univariate analysis indicated significant differences in age, preoperative serum CEA (≤ 30.0 ng/mL/ > 30.0 ng/mL), differentiation of primary tumor (differentiated/undifferentiated), T classification (T1–3/T4), number of hepatic lesions and maximum diameter of the hepatic lesion between the L-OHP (+) and (−) groups. After PS matching using these confounders, RFS was significantly better among patients in the L-OHP (+) group compared with the L-OHP (−) group (HR 0.40, 95% CI 0.17–0.96, p = 0.04). In addition, there was a trend towards better RLRFS among patients in the L-OHP (+) group compared with the L-OHP (−) group (HR 0.42, 95% CI 0.17–1.02, p = 0.055). However, there were no significant differences in CSS, URRFS and EHRFS between the L-OHP (+) and (−) groups.

Conclusions

PS matching analysis demonstrated the efficacy of POAC with an oxaliplatin-based regimen in RFS and RLRFS.

Seroprevalence of anti-SARS-CoV-2 antibodies in Japanese COVID-19 patients

OBJECTIVES

To determine the seroprevalence of anti-SARS-CoV-2 IgG and IgM antibodies in symptomatic Japanese COVID-19 patients.

METHODS

Serum samples (n = 114) from 34 COVID-19 patients with mild to critical clinical manifestations were examined. The presence and titers of IgG antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were determined by a chemiluminescent microparticle immunoassay (CMIA) using Alinity i SARS-CoV-2 IgG and by an immunochromatographic (IC) IgM/IgG antibody assay using the Anti-SARS-CoV-2 Rapid Test.

RESULTS

IgG was detected by the CMIA in 40%, 88%, and 100% of samples collected within 1 week, 1-2 weeks, and 2 weeks after symptom onset in severe and critical cases, and 0%, 38%, and 100% in mild/moderate cases, respectively. In severe and critical cases, the positive IgG detection rate with the IC assay was 60% within one week and 63% between one and two weeks. In mild/moderate cases, the positive IgG rate was 17% within one week and 63% between one and two weeks; IgM was positive in 80% and 75% of severe and critical cases, and 42% and 88% of mild/moderate cases, respectively. On the CMIA, no anti-SARS-CoV-2 IgG antibodies were detected in COVID-19 outpatients with mild symptoms within 10 days from onset, whereas 50% of samples from severe inpatients were IgG-positive in the same period. The IC assay detected higher IgM positivity earlier from symptom onset in severe and critical cases than in mild/moderate cases.

CONCLUSIONS

A serologic anti-SARS-CoV-2 antibody analysis can complement PCR for diagnosing COVID-19 14 days after symptom onset.

A pilot study investigating the effect of pimobendan on the cardiac rhythm and selected echocardiographic parameters of healthy cats

INTRODUCTION

The effects of pimobendan on the heart rhythm in cats are unknown. The purpose of this pilot study was to evaluate the effect of pimobendan on the cardiac rhythm and selected echocardiographic parameters of cats.

ANIMALS, MATERIALS, AND METHODS

Six clinically healthy cats received each of four medication protocols for 15 days, with a washout period of at least one month between each protocol. The protocols were, pimobendan 0.5 mg/kg twice daily (high dosage group), pimobendan 0.25 mg/kg twice daily (standard dosage group), pimobendan 0.125 mg/kg twice daily (low dosage group), and Biofermin R, one tablet twice daily (placebo group). Twenty-four-hour ambulatory electrocardiogram recordings, blood pressure measurements, and echocardiographic examinations were performed after two weeks of each medication protocol. Electrocardiographic, echocardiographic, and blood pressure parameters were compared between the four groups.

RESULTS

The total number of escape/idioventricular/idiojunctional complexes in the high dosage group was significantly higher compared with the placebo, low dosage, and standard dosage groups (p < 0.001). The blood pressure; total number of heart beats per day; and mean, minimum, and maximum heart rates were not significantly different between the groups. The longitudinal strain rate and calculated cardiac output were significantly increased in the high and standard dosage groups.

CONCLUSIONS

The administration of pimobendan, especially at high doses, was associated with increased numbers of escape/idioventricular/idiojunctional complexes in some cats and echocardiographic parameters. Further studies are warranted to investigate both the mechanism underlying the observed changes and what, if any, clinical implications these changes might have in cats with heart disease.

Analysis of ileostomy stool samples reveals dysbiosis in patients with high-output stomas

Construction of a diverting stoma can significantly reduce the onset of severe anastomotic leakage in patients with rectal cancer. High-output stoma is one of the most important potential surgical complications after anal function-preserving surgery with ileostomy. Culture-independent techniques have revealed the interaction of the complex intestinal bacterial ecology with various diseases. Our objective was to evaluate the differences in patient characteristics and gut microbiota distribution features in patients with high-output stomas. The cases of 24 consecutive patients who underwent curative resection for rectal cancer at our hospital between November 2016 and June 2018 were reviewed, and the patients were categorized into high-output and low-output groups. Their microbiota were analyzed using next-generation sequencing of ileostomy stool samples collected on postoperative day 7. There was a significant difference in the percentage of Bacteroidetes between the high-output and low-output groups (14.8% vs 0.5%; p=0.01). The percentage of Clostridium butyricum was increased in the low-output group (p=0.01). After the exclusion of those treated with the probiotic Miya-BM, whose principal component is C. butyricum, analyses revealed no significant differences between the high-output and low-output groups. This pilot study provides the first evidence correlating gut microbiota with the pathogenesis of high- output stoma compared with low-output stoma.

Relationship between effects of riociguat and levels of methemoglobin in patients with chronic thromboembolic pulmonary hypertension

Background

Soluble guanyl cyclase (sGC) is a receptor for nitric oxide (NO) and plays an important role in vascular tonus. sGC stimulant is a therapeutic agent for pulmonary hypertension and an advantage of sGC stimulant over phosphodiesterase (PDE)-5 inhibitors is that sGC stimulant exerts its effect even when NO production is reduced. NO derived from vascular endothelial cells is immediately absorbed by hemoglobin (Hb), which leads to the production of methemoglobin (Met-Hb) when oxidized. Previous report has shown that the therapeutic effect of PDE-5 inhibitors was associated with levels of Met-Hb.

Purpose

In this study, we examined the relationship between the effect of riociguat and levels of Met-Hb in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Methods

The study population comprised 18 patients with CTEPH. Mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) were assessed before and after administration of riociguat, and changes in mPAP and PVR were defined as ΔmPAP and ΔPVR, respectively. Since the level of Met-Hb was obtained as the percentage of Hb (FMet-Hb), the amount of Met-Hb was calculated by following formula:

Met-Hb (mg/dL) = Hb (g/dL) × FMet-Hb (%) × 10.

Results

The amount of Met-Hb value before administration of riociguat was significantly correlated with the degree of improvement in mPAP and PVR after administration of riocigat (R=−0.502, P&lt;0.05 mPAP; R=−0.481, P&lt;0.05 PVR, respectively) as shown in figures.

Conclusion

Our findings suggest that the level of Met-Hb before treatment may predict the therapeutic effect of sGC stimulants in patients with CTEPH.

Funding Acknowledgement

Type of funding source: None

Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer

DNA methylation is an important epigenetic change that is biologically meaningful and a frequent focus of cancer research. Genome-wide DNA methylation is a useful measure to provide an accurate analysis of the methylation status of gastrointestinal (GI) malignancies. Given the multiple potential translational uses of DNA methylation analysis, practicing clinicians and others new to DNA methylation studies need to be able to understand step by step how these genome-wide analyses are performed. The goal of this protocol is to provide a detailed description of how this method is used for the biomarker identification in GI malignancies. Importantly, we describe three critical steps that are needed to obtain accurate results during genome-wide analysis. Clearly and concisely written, these three methods are often lacking and not noticeable to those new to epigenetic studies. We used 48 samples of a GI malignancy (gastric cancer) to highlight practically how genome-wide DNA methylation analysis can be performed for GI malignancies.

Abstract 1973: A novel method for highly sensitive, facile and inexpensive quantitative assessment of aberrant DNA methylation in liquid biopsies

Introduction:

There remains a considerable need for the development of new, simple methods for assessing methylation of cell-free DNA obtained from liquid biopsies. In particular, methods that can achieve highly-sensitive quantitative analysis are needed to enable estimation of tumor burden, invasiveness and recurrence. While standard methylation-sensitive high resolution melt (MS-HRM) analysis methods allow for semi-quantitative assessment of DNA methylation, achieving sufficient sensitivity and accuracy to enable reliable detection of rare circulating tumor DNA (ctDNA) in a large background of predominantly healthy cfDNA remains challenging. We developed a novel method that drastically improves the analytical sensitivity of HRM analysis in order to quantify epiallelic fractions as low as 0.001%. This method was named HiQASP (Highly Quantitative Allele Specific PCR). We demonstrate use of HiQASP for ultra-high-sensitive and quantitative methylation assessment of the promoter region of SEPT9, which is currently used in colorectal cancer screening kits. Here, we utilize this method to assess SEPT9 methylation in cfDNA derived from with liquid biopsies of colorectal cancer patients.

Methods:

All human blood samples were obtained with patient's consent and relevant IRB approval. The plasma specimens were separated with twice centrifugation and cfDNA purified with Qiagen's QIAamp Circulating Nucleic Acid Kit. Bisulfite conversion was performed using Zymo EZ DNA Methylation-Lightning kit according to the manufacturer's instructions. Plasma DNA concentrations were calculated using DX-11Fx (DeNovix) with QuantiFluor (Promega). Analytic specificities and sample epiallelic quantification were determined using synthetic oligonucleotide standards for the bisulfite-converted sequence of methylated and unmethylated SEPT9 were obtained from IDT and GenScript, respectively. Validation of the SEPT9 HiQASP assay was performed using serial dilutions of synthetic oligonucleotides. EpiTaq HS (TaKaRa) and EvaGreen (BioTium) were used to amplify and detect the PCR products, respectively. The equipment QuantStudio 3 (ThermoFisher) was used to amplify and execute HRM analysis.

Results:

Custom HiQASP primers were designed to maximize assay analytical sensitivity and specificity for methylation analysis at the SEPT9 locus. Overall, the SEPT9 HiQASP assay achieved an analytical sensitivity of 0.0005% for both bisulfite-converted unmethylated and methylated synthetic oligonucleotide targets. The entire assay could be performed in only 45 minutes. The potential clinical utility of the assay was also demonstrated using cfDNA derived from of a plasma sample obtained from a colorectal cancer patient. HiQASP analysis indicated the percentage of methylated SEPT9 in this specimen to be 3.8% yielding a total copy concentration of 35 copies of methylated SEPT9 per ml of plasma.

Conclusion:

HiQASP is a highly-sensitive locus-specific assay for facile, rapid and low-cost quantitative assessment of methylated DNA in challenging specimens such as liquid biopsies.

Citation Format: Sachio Nomura, Toshiyuki Kobayashi, Kiichi Sugimoto, Masami Arai, Thomas R. Pisanic, Hirotaka Momose, Kazuhiro Sakamoto, Okio Hino. A novel method for highly sensitive, facile and inexpensive quantitative assessment of aberrant DNA methylation in liquid biopsies [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 1973.

Creatine kinase elevation after robotic surgery for rectal cancer due to a prolonged lithotomy position

Background

Robotic surgery for rectal cancer, which is now performed worldwide, can be associated with elevated creatine kinase levels postoperatively. In this study, we compared postoperative complications between patients undergoing robotic surgery and laparoscopic surgery.

Methods

We identified 66 consecutive patients who underwent curative resection for rectal cancer at Juntendo University Hospital between January 2016 and February 2019. Patients were divided into a conventional laparoscopic surgery (CLS) group (n = 38) and a robotic-assisted laparoscopic surgery (RALS) group (n = 28) before comparing various clinicodemographic factors between the groups.

Results

Patient age and gender, surgical approach (CLS/RALS), pathological T factor, pathological stage, duration of postoperative hospital stay, and postoperative complications were not significantly different between the RALS and CLS groups. However, the operation time was significantly longer in the RALS group (407 min) than in the CLS group (295 min; p < 0.001). Notably, the serum level of creatine kinase on postoperative day 1 was significantly higher in the CLS group (154 IU/L) than in the RALS group (525 IU/L; p < 0.001), despite there being no significant differences in the incidence of rhabdomyolysis. The multivariate analysis showed that RALS/CLS (HR 6.0 95% CI 1.3–27.5, p = 0.02) and operation time (HR 15.9 95% CI 3.79–67.4, p = 0.001) remained independent factors of CK elevation on postoperative day 1.

Conclusions

Clinically relevant positioning injuries and rhabdomyolysis may occur in patients who are subjected to a prolonged and extreme Trendelenburg position or who have extra force applied to the abdominal wall because of remote center displacement. The creatine kinase value should therefore be measured after RALS to monitor for the sequelae of these potential positioning injuries.

Whole-Genome Sequencing of the NARO World Rice Core Collection (WRC) as the Basis for Diversity and Association Studies

Genebanks provide access to diverse materials for crop improvement. To utilize and evaluate them effectively, core collections, such as the World Rice Core Collection (WRC) in the Genebank at the National Agriculture and Food Research Organization, have been developed. Because the WRC consists of 69 accessions with a high degree of genetic diversity, it has been used for >300 projects. To allow deeper investigation of existing WRC data and to further promote research using Genebank rice accessions, we performed whole-genome resequencing of these 69 accessions, examining their sequence variation by mapping against the Oryza sativa ssp. japonica Nipponbare genome. We obtained a total of 2,805,329 single nucleotide polymorphisms (SNPs) and 357,639 insertion-deletions. Based on the principal component analysis and population structure analysis of these data, the WRC can be classified into three major groups. We applied TASUKE, a multiple genome browser to visualize the different WRC genome sequences, and classified haplotype groups of genes affecting seed characteristics and heading date. TASUKE thus provides access to WRC genotypes as a tool for reverse genetics. We examined the suitability of the compact WRC population for genome-wide association studies (GWASs). Heading date, affected by a large number of quantitative trait loci (QTLs), was not associated with known genes, but several seed-related phenotypes were associated with known genes. Thus, for QTLs of strong effect, the compact WRC performed well in GWAS. This information enables us to understand genetic diversity in 37,000 rice accessions maintained in the Genebank and to find genes associated with different phenotypes. The sequence data have been deposited in DNA Data Bank of Japan Sequence Read Archive (DRA) (Supplementary Table S1).

P1512 Combination of mitral annular peak systolic and early diastolic velocities with early transmitral peak flow velocity: a new prognostic echo index in patients with acute coronary syndrome

Background

One of the novel echocardiographic indices reflecting left ventricular (LV) diastolic filling is the combination of mitral annular peak systolic (s’) and early diastolic velocities (e’) with early transmitral peak flow velocity (E); E/(e’ x s’). This index is reported to be useful to predict a prognosis of heart failure patients regardless of their LV ejection fraction (LVEF).Purpose: The aim of this study was to examine whether or not E/(e’ x s’) could predict cardiac events in patients with acute coronary syndrome (ACS).Methods: We studies consecutive ACS patients hospitalized in our institution between December 2009 and February 2012. They underwent echo examination within 7 days after admission. By use of Doppler tissue imaging, e’ and s’ were respectively calculated by averaging the peak velocities measured at both septal and lateral mitral annulus in 4-chamber view. The exclusion criteria were as follows: atrial fibrillation, significant valvular diseases and inadequate echo images. Cardiac events were defined as re-hospitalization due to recurrent ACS and/or heart failure, and cardiac mortality.Results: In total, 168 patients were eligible for this study (mean age 67 ± 11 years, mean LVEF 51.7 ± 10.3 %). Median follow-up period was 22.5 months. During the follow-up, cardiac events occurred in 27 patients (16.1%). Between the patients with cardiac events and those without, there were significant differences in LV end-systolic volume (44.2 ± 29.1 vs 33.2 ± 13.6 ml, p &lt; 0.05), LV mass index (122.4 ± 38.9 vs 107.5 ± 26.4 g/m², p &lt; 0.05), left atrial volume index (31.7 ± 9.2 vs 27.6 ± 9.4 ml/m², p &lt; 0.05), LVEF (45.7 ± 13.5 vs 52.9 ± 9.2 %, p &lt; 0.05), s’ (5.1 ± 1.6 vs 7.1 ± 1.7 cm/sec, p &lt; 0.001), e’ (4.8 ± 1.3 vs 6.0 ± 1.9 cm/sec, p &lt; 0.05), E/e’ (16.4 ± 6.6 vs 12.5 ± 4.9, p &lt; 0.05), E/(e’ x s’) (3.78 ± 2.52 vs 1.94 ± 1.08, p &lt; 0.001), and serum B-type natriuretic peptide (334.7 ± 420.1 vs 113.8 ± 177.2 pg/ml, p &lt; 0.05). While Cox proportional hazard multivariate analysis detected that E/(e’ x s’) and E/e’ were independent predictors of cardiac events, E/(e’ x s’) was more powerful than E/e’ (p = 0.0002 vs p = 0.0072). ROC analysis revealed that 2.35 of E/(e’ x s’) was the optimal cutoff values to predict cardiac events in ACS patients (AUC 0.79). Patients with E/(e’ x s’) &lt;2.35 had significantly better prognosis than the rest (p &lt; 0.0001, Log-rank; Figure)Conclusion: E/(e’ x s’) could be a useful echo marker to predict cardiac events in ACS patients.

Abstract P1512 Figure.

P1508 Left ventricular diastolic function plays a different role on mortality depending on the severity of systolic dysfunction in acute heart failure patients with reduced ejection fraction

Background

It remains to be clarified whether clinical significance of left ventricular (LV) diastolic function differs depending on the severity of LV systolic dysfunction in patients with acute heart failure (AHF). The aim of this study was to examine the prognostic role of LV diastolic function in AHF patients with various systolic dysfunction.Methods: We studied consecutive hospitalized AHF patients with LV ejection fraction (LVEF) &lt;50%. The exclusion criteria were as follows: atrial fibrillation, severe mitral regurgitation, and inadequate echo image quality. They underwent echocardiography on admission. The eligible patients (n = 289, 165 males, 76 ± 10 years) were divided into 4 groups based on LVEF and left atrial pressure (LAP) grade estimated as in the ESC guidelines: Group I (LVEF 40-49% (mildly reduced LVEF)/normal LAP, n = 28), II (mildly reduced EF/increased LAP, n = 38), III (LVEF &lt;40% (severely reduced LVEF)/normal LAP, n = 110), and IV (severely reduced LVEF/increased LAP, n = 113). Cardiac death was examined up to 60 months.Results: In total, 58 patients (20%) died because of cardiac events during the follow-up (mean 20 ± 19 months). In patients with mildly reduced LVEF, Group I showed significantly less cardiac death ratio than II (n = 1 vs 10, Group I vs II, p = 0.03). On the other hand, in patients with severely reduced LVEF, there was no significant difference in cardiac death ratio between Group III and IV (n = 23 vs 24, Group III vs IV, p = 0.80). That is, LAP grade was a prognostic marker when the patients had mild LV systolic dysfunction, whereas it did not contribute to the prediction of cardiac mortality when patients showed severely reduced LV systolic function. Group I showed significantly better prognosis than those with severe LV systolic dysfunction regardless of LAP grade (Group III, IV) (Group I vs III, p = 0.04; Group I vs IV, p = 0.04).Conclusions: LV diastolic function may have a different clinical significance depending on the severity of LV systolic dysfunction in AHF patients.

DNA methylation genome-wide analysis in remnant and primary gastric cancers

BACKGROUND

Although primary (PGC) and remnant gastric cancers (RGC) both originate from the same gastrointestinal organ, they have very distinct clinicopathological behaviors. We hypothesized that there would be distinct differences in DNA methylation patterns that would occur during carcinogenesis of RGC and PGC, and that the differences in methylation patterns may help identify the primary factor contributing to chronic inflammation in patients with RGC.

METHODS

We investigated the genome-wide DNA methylation patterns of PGC and RGC tissues from 48 patients using the Infinium HumanMethylation450 Beadchip assay. The results were validated by quantitative methylation-specific PCR (qMSP) in separate, independent cohorts.

RESULTS

We found that in our training cohort of 48 patients, the most variable genes from the gastric cancer tissues identified by the Infinium HumanMethylation450 Beadchip clustered the resultant heatmap into high and low methylation groups. On multivariate analysis, PGCs contributed significantly to the high methylation group (p = 0.004, OR 12.33), which suggested that the promoter methylation status in PGC is higher than that in RGC. Supporting this conclusion was the finding that in a separate qMSP analysis in a test cohort, the EPB41L3 gene, chosen because of its high β value on microarray analysis in the gastric cancer tissues, had significantly higher DNA promoter methylation in cancer tissues in the validation PGC tissues than in RGC.

CONCLUSIONS

This study demonstrated that promoter methylation status in PGC is higher than in RGC. This result may reflect the effects of the absence of Helicobacter pylori on the reduced DNA methylation in the remnant stomach.

pymzML v2.0: introducing a highly compressed and seekable gzip format

Motivation

In the new release of pymzML (v2.0), we have optimized the speed of this established tool for mass spectrometry data analysis to adapt to increasing amounts of data in mass spectrometry. Thus, we integrated faster libraries for numerical calculations, improved data retrieving algorithms and have optimized the source code. Importantly, to adapt to rapidly growing file sizes, we developed a generalizable compression scheme for very fast random access and applied this concept to mzML files to retrieve spectral data.

Results

pymzML performs at par with established C programs when it comes to processing times. However, it offers the versatility of a scripting language, while adding unprecedented fast random access to compressed files. Additionally, we designed our compression scheme in such a general way that it can be applied to any field where fast random access to large data blocks in compressed files is desired.

Availability and implementation

pymzML is freely available on https://github.com/pymzML/pymzML under GPL license. pymzML requires Python3.4+ and optionally numpy. Documentation available on http://pymzml.readthedocs.io.

Serum oxidative stress is an independent prognostic marker in colorectal cancer

Background

Few previous studies have investigated the relationship between serum oxidative stress and the status of patients with colorectal cancer. Our aim in the current study was to investigate the significance of serum oxidative stress as a prognostic marker in these patients.

Methods

The subjects were 53 patients who underwent curative resection of high-risk stage II or stage III colorectal cancer. The correlation of serum oxidative stress (Reactive Oxygen Metabolites Test: d-ROMs Test) with recurrence-free survival was examined.

Results

There were no significant differences in d-ROMs between the recurrence and non-recurrence groups at four time points (0M: before the start of postoperative adjuvant chemotherapy; and 1M: 1 month; 3M: 3 months; and 6M: 6 months after the start of postoperative adjuvant chemotherapy). Only the 3M/0M d-ROMs (the value at 3M relative to the value at 0M) was increased compared with the other time points in the recurrence group, as well as with all time points in the non-recurrence group. In univariate analysis, there were significant differences in recurrence-free survival with respect to N classification (P=0.004) and 3M/0M d-ROMs (P=0.002). In multivariate analysis, both N classification and serum oxidative stress were found to be significant independent prognostic factors (P=0.02, HR=4.49; P=0.02, HR=5.61, respectively).

Conclusions

The results of this study demonstrate the prognostic value of serum oxidative stress in colorectal cancer.

Effectiveness of Endoscopic Sclerotherapy with Aluminum Potassium Sulfate and Tannic Acid as a Non-Surgical Treatment for Internal Hemorrhoids

BACKGROUND/AIMS

Sclerotherapy with aluminum potassium sulfate and tannic acid (ALTA) has a potent effect on internal hemorrhoids. In this retrospective study, we compared the effects of endoscopic ALTA therapy and standard ALTA therapy.

METHODS

We investigated patients who underwent treatment for internal hemorrhoids at our institution between 2014 and 2016. They were divided into a standard ALTA group (n=33, treated using proctoscopy) and an endoscopic ALTA group (n=48). We compared the clinical findings between the 2 groups.

RESULTS

There were no intergroup differences in background factors. The mean ALTA dose was 21.9±7.2 mL and 17.8±3.4 mL in the standard and endoscopic ALTA groups, respectively (p<0.01). Adverse events occurred in 4 patients (12.1%) from the standard ALTA group and 6 patients (12.5%) from the endoscopic ALTA group. In both groups, the patients reported good satisfaction with the therapeutic effect at 1 month after the procedure. Hemorrhoids recurred in 2 patients (6.3%) from the standard ALTA group and 4 patients (8.3%) from the endoscopic ALTA group.

CONCLUSION

Endoscopic ALTA sclerotherapy is equivalent to standard ALTA therapy in terms of efficacy, adverse events, and recurrence. Therefore, it is a useful non-surgical option for patients with internal hemorrhoids who prefer a less invasive treatment.

Abstract 819: DNA methylation genome-wide analysis in remnant gastric cancer

Purpose: Although primary gastric cancers (PGC) and remnant gastric cancers (RGC) both originate from the same gastrointestinal organ, they have very distinct clinicopathological behaviors. Due to the importance of chronic inflammation in the carcinogenesis of gastric malignancies, we hypothesized that DNA promoter hypermethylation would play a critical role in the carcinogenesis of RGC as well as PGC.

Methods: We investigated the genome-wide DNA methylation patterns of PGC and RGC tissues from 48 patients from an academic medical center in Japan using the Infinium HumanMethylation450 BeadChip assay. The results were validated by quantitative methylation-specific PCR (qMSP) in separate, independent cohorts.

Results: We found that in our training cohort of 48 patients, genes from the gastric cancer tissues identified by the Infinium HumanMethylation 450 Beadchip clustered into high and low methylation groups on multivariate analysis (p=0.004, OR=12.33). PGCs contributed significantly to the high methylation group suggesting that the DNA promoter methylation status in PGC is higher than that in RGC. Supporting this conclusion was the finding that in a separate qMSP analysis in a test cohort, the gene A had significantly higher DNA promoter methylation in cancer tissues in the validation PGC tissues than in RGC.

Conclusion: This study demonstrated that DNA promoter methylation status in PGC is higher than in RGC. This result may reflect the effects of Helicobacter pylori on the induction of DNA methylation in the remnant stomach.

Citation Format: Tomoaki Ito, Kiichi Sugimoto, Hajime Orita, Masahiro Maeda, Hiroshi Moro, Toshikazu Ushijima, Hitoshi Katai, Ryo Wada, Kazuhiro Sakamoto, Koichi Sato, Malcolm V. Brock. DNA methylation genome-wide analysis in remnant gastric 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 819.

Current status of venous thromboembolism development during the perioperative period for colorectal cancer, its prevention with enoxaparin, and monitoring methods

Background: There is a high incidence of venous thromboembolism (VTE) during the perioperative period for cancer. Therefore, there is an urgent need to elucidate the perioperative onset and appropriate prophylaxis for VTE. Purpose: VTE during the perioperative period for colorectal cancer was evaluated by lower limb venous ultrasonic examinations (lower limb echo) under enoxaparin prophylaxis. We also examined the relationship between hemorrhagic adverse events and anti-Xa factor activity. Patients and methods: Eighty-three subjects who underwent lower limb echo during the perioperative period for colorectal cancer were prospectively included. Enoxaparin was administered for 5 days, from day 1 to day 5 after surgery. Lower limb echo was performed before surgery and on day 5 after surgery. The activated partial thromboplastin time, D-dimer levels, and anti-Xa factor activity were measured before surgery and on days 1, 3, 5, 7, and 9 after surgery. Results: VTEs before surgery were observed on lower limb echo for 16 patients (19.2%). Three patients (3.6%) had a new thrombus during the perioperative period. The preoperative D-dimer level was an independent prognostic factor for newly formed postoperative VTEs (p=0.0036; odds ratio, 19.37). Three patients (3.6%) had hemorrhagic events; however, there was no significant trend for anti-Xa factor activity. Conclusion: VTE prevention using enoxaparin was relatively safe, and D-dimer measurements before surgery were useful for predicting perioperative VTE.

Laparoscopic right colectomy for a patient with situs inversus totalis

Situs inversus totalis (SIT) is rare congenital anomaly characterized by an inversion of the thoracic and abdominal viscera that crates a mirror image. Recently, several laparoscopic operations have been reported in patients with SIT. We herein report the case of a 76-year-old woman with ascending colon cancer who received a laparoscopic right colectomy. She was discharged on the 12th day after the operation, without any complications. Laparoscopic surgery in the patients with SIT remains a technical challenge for the surgeon. However, careful understanding of mirror image anatomy and planning of laparoscopic procedure permitted safe operation using technique in ordinary cases. Thus, laparoscopic surgery for colon cancer in the patients with SIT is safe and feasible.