The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis

PURPOSE

Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure.

METHODS

Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure.

RESULTS

Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure.

CONCLUSIONS

Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

Pks-positive Escherichia coli in tumor tissue and surrounding normal mucosal tissue of colorectal cancer patients

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer

PURPOSE

Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking.

METHODS

We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20 days.

RESULTS

In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72).

CONCLUSIONS

A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

Successful management of malignant colovesical fistula using covered colonic self-expanding metallic stent: a case report

BACKGROUND

A colovesical fistula (CVF) is commonly treated by resection of the intestine containing the fistula or creation of a defunctioning stoma. We herein report a case of successful fistula closure and avoidance of colostomy after placement of a covered colonic self-expanding metallic stent (SEMS) as a palliative treatment for a malignant CVF.

CASE PRESENTATION

A 75-year-old man undergoing infusional 5-fluorouracil and irinotecan chemotherapy plus bevacizumab for recurrent peritoneal dissemination of rectal cancer was admitted to our hospital because of fecaluria with a high-grade fever. Blood tests showed a moderate inflammatory reaction (white blood cell count, 9200/mm3; C-reactive protein, 11.03 mg/dL; procalcitonin, 1.33 ng/mL). Urinary sediment examination showed severe bacteriuria. Abdominal contrast-enhanced computed tomography showed intravesical gas, thickening of the posterior wall of the bladder, and irregular thickening of the sigmoid colon wall contiguous with the posterior bladder wall. Magnetic resonance imaging (MRI) clearly showed a fistula between the bladder and sigmoid colon. Colonoscopy revealed a circumferential malignant stricture 15 cm from the anal verge, and a fistula to the bladder was identified by water-soluble contrast medium. We diagnosed a complicated urinary tract infection (UTI) associated with a CVF due to peritoneal dissemination and started empirical treatment with sulbactam/ampicillin. Given the absence of active inflammatory findings around the fistula on MRI and the patient's physical frailty, we decided to place a covered SEMS to close the fistula. Under fluoroscopic and endoscopic guidance, a covered colonic SEMS of 80-mm length and 20-mm diameter was successfully deployed, and the fistula was sealed immediately after placement. Urine culture on day 3 after stenting was negative for bacteria, and a contrast study on day 5 showed no fistula. The patient was discharged home on day 6 with no complications. The UTI did not recur for 4 months after discharge.

CONCLUSIONS

A covered colonic SEMS was useful for sealing a malignant CVF in a patient unfit for surgery, and MRI was valuable to determine the status of the fistula. A covered colonic SEMS could be an alternative to surgical treatment for CVFs in patients who require palliative care.

Long-term outcomes between self-expandable metallic stent and transanal decompression tube for malignant large bowel obstruction: A multicenter retrospective study and meta-analysis

Aim

To compare the oncological outcomes between self-expandable metallic stent (SEMS) as a bridge to surgery and transanal decompression tube (TDT) placement for malignant large bowel obstruction (MLBO).

Methods

A total of 287 MLBO patients who underwent SEMS (n = 137) or TDT placement (n = 150) were enrolled in this multicenter retrospective study. Overall survival (OS) and disease-free survival (DFS) between the two groups were compared. A meta-analysis was performed using random-effects models to calculate odd ratios (OR) with 95% confidence intervals (CIs).

Results

Postoperative complications of Clavien-Dindo grade ≥II and ≥III occurred frequently in the TDT group compared with the SEMS group (P = 0.002 and 0.005, respectively). The 3-y OS in the overall cohort and 3-y DFS in the pathological stage II/III cohort in the SEMS and TDT groups were 68.6% and 71.4%, and 71.0% and 72.6%, respectively. The survival differences were not significantly different in the OS and DFS analyses (P = 0.819 and P = 0.892, respectively). A meta-analysis of nine studies (including our cohort data) demonstrated no significant difference between the SEMS and TDT groups for 3-y OS and DFS (OR = 0.96, 95% CI = 0.57-1.62, P = 0.89 and OR = 0.69, 95% CI = 0.46-1.04, P = 0.07, respectively).

Conclusion

Our study demonstrated that SEMS placement had no inferiority regarding long-term outcomes, including OS and DFS, compared with TDT placement. Considering the short-term benefits of SEMS placement, this could be a preferable preoperative decompression method for MLBO.

Postoperative infectious complications have a negative oncological impact in patients after stent placement with malignant large bowel obstruction

PURPOSE

In this study, we aimed to investigate the oncological impact of postoperative infection in patients with malignant large bowel obstruction managed by self-expandable metallic stent placement as a bridge to surgery.

METHODS

The cohort of this multicenter retrospective study comprised 129 patients with pathological stage II/III malignant large bowel obstruction who had undergone bridge to surgery. Patients were allocated to no-postoperative infection (n = 116) and postoperative infection groups (n = 13).

RESULTS

The postoperative infection group had a significantly greater proportion of men, fewer harvested lymph nodes, and longer postoperative hospital stays than did the no-postoperative infection group. Self-expandable metallic stent-related variables, including clinical failure, were not associated with postoperative infection. Male sex and low body mass index were identified as risk factors for postoperative infection by multivariate logistic regression. Three-year relapse-free survival rates were 75.5% and 30.8% in the no-postoperative infection and postoperative infection groups, respectively; this difference is statistically significant. Male sex, postoperative infection, and T4 were identified as independent prognostic factors by multivariate Cox proportional hazard analysis. The postoperative infection group had a significantly higher total recurrence rate and shorter interval to recurrence than did the no-postoperative infection group.

CONCLUSION

To the best of our knowledge, this is the first study to show that postoperative infection in bridge to surgery patients has a negative oncological impact. This finding indicates that further improvement in perioperative management of bridge to surgery patients is required to minimize postoperative infection and that patient-risk stratification and additional therapy would contribute to improving oncological outcomes.

Clostridium perfringens sepsis after pancreatoduodenectomy: a case report

Background

Clostridium perfringens sepsis associated with massive intravascular hemolysis has an extremely poor prognosis. We here report a case of C. perfringens sepsis associated with massive intravascular hemolysis that developed secondary to a post-pancreaticoduodenectomy (PD) hepatic abscess.

Case presentation

A 70-year-old man with Type 2 diabetes underwent PD for an ampulla of Vater carcinoma. His postoperative course was uneventful. He was discharged on the 16th post-operative day (POD 16) after confirming no major abnormalities on abdominal contrast computed tomography (CT) on POD 14 or laboratory results on POD 16. Two days after discharge, he was readmitted because of fever and chills. Laboratory tests showed only a mild inflammatory reaction (white blood cell count, 11,980/mm³; C-reactive protein, 2.07 mg/dL). Abdominal CT showed an irregular, approximately 20-mm diameter, low-density area in the liver S6 region that had not been seen on a recent previous scan. We initially suspected postoperative cholangitis associated with biliary reconstruction and started empirical treatment with sulbactam/ampicillin after drawing blood for culture. Eight hours after admission, he developed septic shock with body temperature 40.0 ℃ and blood pressure 70/40 mm Hg. Laboratory findings showed a severe inflammatory reaction, severe anemia, and massive hemolysis (white blood cell count, 37,400/mm³; hemoglobin, 7.7 g/dL; total bilirubin, 8.05 mg/dL; direct bilirubin, 2.66 mg/dL; and lactate dehydrogenase, 1686 U/L). Hemoglobinuria was noted in the urinary catheter output. Repeat CT 9 h after admission showed the low-density area in S6 had become a gas-forming abscess. C. perfringens sepsis was strongly suspected on the basis of these findings and the abscess was drained percutaneously immediately after its diagnosis. His vital signs improved dramatically and he recovered within 24 h. Blood and abscess cultures grew C. perfringens 4 days after admission, leading to a definitive diagnosis of C. perfringens sepsis associated with massive intravascular hemolysis. He was discharged 18 days after admission. His sepsis has not recurred.

Conclusions

Clostridium perfringens infection should be considered in patients who have undergone PD and present with gas-forming hepatic abscesses and/or sepsis associated with intravascular hemolysis. Prompt aggressive treatment is crucial, because C. perfringens infections can cause death within hours.

TGF-β1 increases cellular invasion of colorectal neuroendocrine carcinoma cell line through partial epithelial-mesenchymal transition

Epithelial–mesenchymal transition (EMT) plays a pivotal role in cancer progression and metastasis in many types of malignancies, including colorectal cancer. Although the importance of EMT is also considered in colorectal neuroendocrine carcinoma (NEC), its regulatory mechanisms have not been elucidated. We recently established a human colorectal NEC cell line, SS-2. In this study, we aimed to clarify whether these cells were sensitive to transforming growth factor beta 1 (TGF-β1) and whether EMT could be induced through TGF-β1/Smad signaling, with the corresponding NEC cell-specific changes in invasiveness. In SS-2 cells, activation of TGF-β1 signaling, as indicated by phosphorylation of Smad2/3, was dose-dependent, demonstrating that SS-2 cells were responsive to TGF-β1. Analysis of EMT markers showed that mRNA levels changed with TGF-β1 treatment and that E-cadherin, an EMT marker, was expressed in cell-cell junctions even after TGF-β1 treatment. Invasion assays showed that TGF-β1-treated SS-2 cells invaded more rapidly than non-treated cells, and these cells demonstrated increased metalloproteinase activity and cell adhesion. Among integrins involved in cell-to-matrix adhesion, α2-integrin was exclusively upregulated in TGF-β1-treated SS-2 cells, but not in other colon cancer cell lines, and adhesion and invasion were inhibited by an anti-α2-integrin blocking antibody. Our findings suggest that α2-integrin may represent a novel therapeutic target for the metastasis of colorectal NEC cells.

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NEC cell line SS-2 is responsive to TGF-β1.

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TGF-β1 stimulation induces partial EMT, maintaining E-cadherin in SS-2 cells.

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TGF-β1-treated SS-2 cells exhibit increase in metalloproteinase activity and cell adhesion.

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α2-integrin is exclusively upregulated in TGF-β1-treated SS-2 cells.

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Use of anti-α2-integrin blocking antibody inhibits enhanced adhesion and invasion.

Colonic stent as a bridge to surgery versus emergency resection for right-sided malignant large bowel obstruction: a meta-analysis

BACKGROUND

Preoperative colonic stenting for malignant large bowel obstruction (MLBO), also called bridge to surgery (BTS), is considered a great substitute treatment for emergency resection (ER) in the left-sided colon. However, its efficacy in the right-sided colon remains controversial. This systematic review and meta-analysis aimed to compare the postoperative short-term outcomes between BTS and ER for right-sided MLBO.

METHODS

A comprehensive electronic literature search throughout December 2020 was performed to identify studies comparing short-term outcomes between BTS and ER for right-side MLBO. The main outcome measures were postoperative complications and mortality rates. A meta-analysis was performed using a fixed-effect or a random-effect method to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs).

RESULTS

Seven studies were included in this meta-analysis, comprising 5136 patients, of whom 1662 (32.4%) underwent BTS and 3474 (67.6%) underwent ER. This meta-analysis demonstrated that BTS resulted in reductions in postoperative complications (OR = 0.78; 95% CI: 0.66-0.92) and mortality (OR = 0.51; 95% CI: 0.28-0.92) than ER.

CONCLUSION

The results of this meta-analysis indicate that BTS for right-sided MLBO confers preferable short-term outcomes as well as for left-sided. This suggests that BTS results in a reduction of postoperative complications and mortality for right-sided MLBO than ER.

A rapidly growing small intestinal metastasis from lung cancer

Small intestinal metastasis from lung cancer is a relatively rare occurrence, and often causes intestinal obstruction, gastrointestinal perforation, and/or gastrointestinal bleeding making it is an oncological emergency. Many patients have been reported to undergo emergency surgery owing to the rapid progression of the intestinal metastatic lesion; however, information regarding the changes that occur in such metastases over time remains lacking. Therefore, we analyzed 4 patients who had small intestinal metastases arising from lung cancer, who were treated during a 10-year period (January 2011 to December 2020), and whose tumor diameter changes were recorded. The average tumor volume growth rate was 1.48 (1.31-1.78) -fold, and the median observation period was 22 (4-39) days, showing a rapid increase. Histopathologically, in patients with a high degree of primary tumor atypia, rapid tumor growth caused by intratumoral hemorrhage may occur. This was considered to be one of the factors responsible for the rapid increase in tumor volume.

Detection of KRAS mutations in circulating tumour DNA from plasma and urine of patients with colorectal cancer

BACKGROUND

Circulating tumour DNA (ctDNA) is very useful for purposes of cancer genetics; however, it has some limitations. Recently, ctDNA in body fluids, such as urine, sputum, and pleural effusion, has been investigated. The aim of this study was to evaluate the quantity of ctDNA derived from urine (trans-renal ctDNA) and the accuracy of KRAS mutation detection in relation to disease stage in colorectal cancer.

METHODS

Urine, plasma, and tissue samples were collected from consecutively resected colorectal cancer patients. DNA was extracted from each sample and the quantity was determined. From each DNA sample, KRAS mutations were detected using droplet digital PCR.

RESULTS

200 patients participated and KRAS mutations were detected in 84 patients (42.0%) from tumour tissue. The concentration of trans-renal ctDNA (trtDNA) was significantly lower than that of plasma; however, there was no significant difference between the sensitivity using ctDNA and that using trtDNA (29.8% VS 33.3%, p = 0.62). Concordance between these two tests was only 17.5%. Combination analysis (ctDNA + trtDNA) improved the sensitivity to 53.6%, and sensitivity was significantly higher than that of corresponding single assays (p = 0.003). In early cancer stages, trtDNA had greater sensitivity for detecting KRAS mutations than ctDNA (37.7% vs. 21.3%, p = 0.047). Conversely, it was less useful for advanced cancer stages (21.7% vs. 52.2%, p = 0.07). Notably, KRAS mutations were detected using ctDNA or trtDNA in 12 of 116 (10.3%) patients who had no KRAS mutations in their tissue samples.

CONCLUSIONS

trtDNA and ctDNA have equal potential and combination analysis significantly improved the sensitivity.

Elevated serum carcinoembryonic antigen level after curative surgery is a prognostic biomarker of stage II-III colorectal cancer

BACKGROUND

High preoperative carcinoembryonic antigen (CEA) is a well-known risk factor for stage II-III colorectal cancer (CRC); however, in most cases, cancer does not recur. Conversely, postoperative CEA (post-CEA) is occasionally measured, and high post-CEA patients often develop recurrence; however, the clinical significance of post-CEA testing is unknown. The purpose of this study was to determine whether post-CEA elevation might indicate a poor prognosis for stage II-III CRC patients who underwent curative surgery.

PATIENTS AND METHODS

482 patients with pathological stage II-III CRC were included. Univariate and multivariate analyses were performed to evaluate post-CEA levels.

RESULTS

Multivariate analysis showed that elevated post-CEA (hazard ratio (HR): 3.14, P < 0.001), pathological lymph node metastasis (pN+), and pathological T4 (pT4) are associated with poor recurrence-free survival (RFS), and that elevated post-CEA (HR: 3.12; P = 0.002), pN+, pT4, age >70, and smoking are independently associated with poor overall survival. Subgroup analysis among stage III patients, in combination with the risk classification of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) study, showed that elevated post-CEA is a significant indicator of poor prognosis for RFS in both low-risk (73.8% vs. 21.2%, P < 0.001) and high-risk (49.9% vs. 25.0%, P = 0.04) groups.

CONCLUSIONS

Post-surgical CEA elevation is independently associated with poor prognosis in stage II-III CRC. Adding post-CEA levels to the IDEA risk classification may provide a more reliable indicator of the need for individualized surveillance and adjuvant chemotherapeutic strategies.

PIK3CA mutation detected by liquid biopsy in patients with metastatic breast cancer

BACKGROUND

PIK3CA is associated with tumor progression, and the prevalence of its mutation is high in breast cancer. Liquid biopsy offers convenient, non-invasive, and real-time insight into genetic alternation. In this study, we attempted to detect PIK3CA mutations in breast cancer patients through liquid biopsy.

METHODS

We recruited patients with histologically confirmed breast cancer with distant metastases between April 2020 and September 2020. Circulating DNA was extracted from plasma (ctDNA) and exosomes (exoDNA). PIK3CA mutations (exons 9 and 20) were analyzed by droplet digital PCR.

RESULTS

Of a total of 52 patients recruited, 16 had PIK3CA mutations in their tumor tissue or blood, which comprised 9 with exon 9 mutations (E542K and E545K) and 8 with exon 20 mutations (H1047L and H1047R). In 8 (15%) of the 52 patients, PIK3CA mutations were detected by liquid biopsies using ctDNA in 5 (9%), exoDNA in 6 (11%), and both ctDNA and exoDNA in 3 (6%). Of the 8 patients with PIK3CA mutations detected by liquid biopsies, 3 had no PIK3CA mutations in the primary tumors.

CONCLUSIONS

PIK3CA mutations can be detected using liquid biopsy even in patients with no PIK3CA mutations in their primary tumors; thus, combination analysis using tissue and liquid biopsies can provide clinically useful information for patients with breast cancer.

Systemic Chemotherapy is a Promising Treatment Option for Patients with Colonic Stents: A Review

Approximately 10% of patients with colorectal cancer (CRC) develop malignant large bowel obstruction (MLBO) at diagnosis. Furthermore, for 35% of patients with MLBO, curative primary tumor resection is unfeasible because of locally advanced disease and comorbidities. The practice of placing a self-expandable metallic stent (SEMS) has dramatically increased as an effective palliative treatment. Recent advances in systemic chemotherapy for metastatic CRC have significantly contributed to prolonging patients' prognosis and expanding the indications. However, the safety and efficacy of systemic chemotherapy in patients with SEMS have not been established. This review outlines the current status of this relatively new therapeutic strategy and future perspectives. Some reports on this topic have demonstrated that 1) systemic chemotherapy and the addition of molecular targeted agents contribute to prolonged survival in patients with SEMS; 2) delayed SEMS-related complications are a major concern, and this requires strict patient monitoring; however, primary tumor control by chemotherapy might result in decreased complications, especially regarding re-obstruction; and 3) using bevacizumab could be a risk factor for SEMS-related perforation, which may be lethal. Although this relatively new approach for unresectable stage IV obstructive CRC requires a well-planned clinical trial, this therapy could be promising for patients who are unideal candidates for emergency surgery and require immediate systemic chemotherapy.

[A Case of Peritoneal Dissemination of Colorectal Cancer in Which Conversion Surgery Could Be Performed after Reduction with CAPOX/Bevacizumab]

A woman in her 60s underwent lower endoscopy due to a positive fecal occult blood test. A type 2 tumor was found in the cecum, and a biopsy resulted in the diagnosis of adenocarcinoma(tub2). Contrast-enhanced CT showed an enlarged paracolonic lymph node but no distant metastasis, so the patient underwent a laparoscopic-assisted ileocolic resection and D3 lymph node dissection for cecum cancer. The pathology was pT3, pN2b, pM0, pStage Ⅲc, and 12 courses of FOLFOX were administered as adjuvant chemotherapy. Twenty-four months after the completion of adjuvant chemotherapy, an elevated CEA was observed, and a PET-CT was performed, which showed multiple peritoneal disseminated nodules with FDG accumulation. Based on this finding, CAPOX/bevacizumab therapy was introduced, and on completion of 4 courses, the PET-CT showed a decrease in the size of the nodules and the disappearance of FDG accumulation. Based on this, the patient underwent resection. A peritoneal dissemination resection and bilateral ovariectomy were laparoscopically performed, and the patient is currently under observation. In patients with metastatic recurrence of peritoneal dissemination who underwent complete resection, treatment with CAPOX/bevacizumab may allow for disease control and provide a long-term prognosis.

Does the diameter of colonic stent influence the outcomes in bridge-to-surgery patients with malignant large bowel obstruction?

PURPOSE

This study investigated the short- and long-term outcomes of 18- and 22-mm-diameter self-expandable metallic stent (SEMS) as a bridge to surgery (BTS) in patients with malignant large bowel obstruction (MLBO).

METHODS

Sixty-nine pathological stage II and III colorectal cancer patients who underwent BTS were included in this multi-institutional retrospective study. Patients were divided into two groups regarding the diameter of SEMS: an 18-mm group (n = 30) and a 22-mm group (n = 39).

RESULTS

There was no significant difference in the clinical success rate, but both of the two re-obstructions observed occurred in the 18-mm group. The 18-mm group showed a trend toward a higher incidence of overall postoperative complications (Clavien-Dindo grading ≥ II) than the 22-mm group (33.3% vs. 10.3%, P = 0.061). The 3-year disease-free and overall survival showed no significant differences between the 18- and 22-mm groups (78.2% vs. 68.8%, P = 0.753 and 92.8% vs. 82.1%, P = 0.471, respectively).

CONCLUSION

SEMS of 18 and 22 mm diameter confer statistically equivalent short- and long-term outcomes as a BTS.

Surgical Management of Colonic Perforation in a Patient with Vascular Ehlers-Danlos Syndrome with no Family History: A Case Report

Vascular Ehlers-Danlos syndrome (vEDS) is a rare autosomal dominant connective tissue disease. Patients with vEDS are at a high risk of developing severe complications (such as arterial aneurysm, arterial rupture, intestinal rupture) at an early age. We report a case of colonic perforation in a vEDS patient with no family history of that disease. A 28-year-old man with abdominal pain arrived at our hospital in an ambulance. The preoperative diagnosis was panperitonitis due to gastrointestinal perforation. Although his parents had not suffered from vEDS, he had been diagnosed with the disease at 25 years of age because of his history of arterial dissection. We performed an emergency operation using Hartmann's procedure to construct a descending colostomy. There remains a lack of consensus on surgical management in vEDS patients with gastrointestinal perforation because of the limited number of reported cases.

Even a partial pathological response is associated with lower relapse rates in patients with operable rectal cancer undergoing neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy to treat locally advanced rectal cancer is an effective therapeutic strategy for the prevention of local recurrence and distant organ metastasis after surgery.

OBJECTIVES

To assess the prognostic significance of histopathological tumor response in rectal cancer patients undergoing neoadjuvant chemotherapy.

METHODS

This study included patients with operable rectal cancer who received neoadjuvant chemotherapy using the FOLFOX regimen (5-fluorouracil, l-leucovorin, and oxaliplatin) in a hospital between February 2012 and November 2017. The main outcome measure was disease-free survival with respect to histopathological response to neoadjuvant chemotherapy in resected specimens.

RESULTS

The median follow-up was 32 months. Of 48 patients treated with neoadjuvant FOLFOX, 24 (50%) were classified as responders, which included two patients with pathological complete response and 22 patients with partial response. The remaining 24 patients (50%) were classified as nonresponders. Responders had a significantly better 3-year disease-free survival than nonresponders (86% vs. 62%, p = .02).

CONCLUSIONS

Patients whose surgical specimens show a pathological complete response or partial response have good oncologic outcomes.

Abstract 710: Exosomal DNA has the potential to detect circulating tumor DNA in patients with colorectal cancer

[Introduction] Exosomes are small vesicles of endosomal origin, which are released by all cell types, and are involved in physiological and pathological processes including cancer progression and metastasis. Exosomes comprise proteins, lipids, and nucleic acids such as RNA and DNA (exoDNA). Circulating exoDNAs harboring mutations are detected in patients with pancreatic or colorectal cancer. [Objective] To evaluate the clinical utility of detecting RAS mutations in exoDNAs of patients with colorectal cancers.

[Methods] We prospectively recruited 25 patients with RAS mutations in cells of their colorectal tissues. Circulating exoDNA was extracted from exosomes in 1 ml of preoperative plasma. Circulating cell-free DNA (ccfDNA) was concurrently extracted from 1 ml of plasma. We identified RAS mutations in exoDNAs and ccfDNAs using droplet digital PCR (ddPCR, Biorad).

[Results] We analyzed the exoDNAs of patients with right-sided (n = 13) and left-sided (n = 12) colon cancers (Stage II, [n = 9]; Stage III, [n = 9], Stage IV, [n = 7]). The median concentrations of exoDNA and ccfDNA were 52.3 ng/ml (32.1-223 ng/ml) and 132 ng/ml (41.3-4333 ng/ml). RAS mutations were detected in exoDNAs of 13 patients (52.0%) and in the ccfDNAs of 5 patients (20%) (P=0.03). The sensitivities of exoDNAs and ccfDNAs were equivalent (57.1%). However, for Stages II and III, the sensitivities of exoDNAs were higher compared with those of ccfDNAs. Notably, the sensitivity of exoDNA of Stage III was 77.8%. RAS mutations were undetectable in ccfDNAs of patients without detectable mutations in exoDNAs. The median mutation allele frequencies of exoDNA and ccfDNAs were 12.1% and 18.0%, respectively.

[Conclusion] Previously reported mutation-detection rates using Stages VI and III ccfDNAs are 90% and 15%, respectively. Here, the sensitivities using ccfDNAs for Stage II or III were low as well. Conversely, the sensitivities using exoDNAs were equivalently high in Stages III and Stage IV. These findings indicate that exoDNA has superior potential for detecting circulating tumor DNA compared with that of ccfDNA

Citation Format: Sho Kuriyama, Takeshi Yamada, Michihiro Koizumi, Seiichi Shinji, Akihisa Matsuda, Ryo Ohta, Goro Takahashi, Masahiro Hotta, Keisuke Hara, Kohki Takeda, Koji Ueda, Hiroshi Yoshida. Exosomal DNA has the potential to detect circulating tumor DNA in patients with 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 710.

Abstract 6015: A newly established neuroendocrine carcinoma cell line from a human ascending colon tumor shows high proliferation and CD133 expression in spherical cancer stem cell-like formation

BACKGROUND: The current incidence of neuroendocrine tumor (NET) is 0.6 cases per 100,000 people, although it has increased 50-fold over the last 35 years and is becoming increasingly clinically important. Neuroendocrine carcinoma (NEC) is a type of malignant NET associated with poor prognoses. However, the molecular basis and clinical characteristics of NEC have not yet been fully investigated due to a lack of patient biopsies to derive cell lines and established cell lines. Here, we report a newly established and characterized NEC cell line (SS-2) derived from a human ascending colon tumor. Furthermore, we investigated the ability of SS-2 cells to form spherical cancer stem cells (CSCs) and express CSC markers.

MATERIALS AND METHODS: The SS-2 cell line was derived from a tumor resection of the ascending colon from 59-year old Japanese woman with stage four NEC. The Ki-67 labeling index of the resected tumor was &gt;20% and, thus, the tumor was diagnosed as NEC. The characteristics of SS-2 cells transplanted subcutaneously into nude mice was determined. siRNA suppression of the neuroendocrine marker, INSM-1 was detected in SS-2 cells by western blotting. Additionally, SS-2 cells were seeded onto ultra-low attachment plates to detect sphere-formation and the expression of CSC markers, with confirmation by FACS analysis. Additionally, we compared the effect of commonly-used anti-colorectal chemotherapeutics on SS-2 cells and conventional colorectal cancer cells (Caco-2) using cell viability assay. Statistical analysis was done using Student's t test with P-values &lt; 0.05 considered statistically significant.

RESULTS: Characteristics of the resected tumor were retained in the SS-2 cells and in the xenograft in nude mice. INSM-1 was detected in SS-2 cell lysates and in nuclei of established SS-2 cells. siRNA targeting INSM-1 decreased INSM-1 mRNA levels but did not affect levels of chromogranin A and synaptophysin mRNA. SS-2 cells formed spheres when seeded onto ultra-low attachment plates that expressed higher levels of CD133 compared to SS-2 cells cultured under adherent conditions, which was also confirmed upon FACS analysis. After the addition of oxaliplatin and 5-FU, cell viabilities were higher in SS-2 cells than Caco-2 cells.

CONCLUSION: We established a novel NEC cell line, derived from a human ascending colon tumor, which we transplanted into nude mice. We determined that the CSC marker, CD133 is highly expressed in SS-2 cells, and hence posit that combination therapy of chemotherapeutics together with anti-CSC therapy may have increased efficacy against NEC.

Citation Format: Seiichi Shinji, Norihiko Sasaki, Takeshi Yamada, Michihiro Koizumi, Ryo Ohta, Akihisa Matsuda, Goro Takahashi, Masahiro Hotta, Takuma Iwai, Keisuke Hara, Kohki Takeda, Koji Ueda, Sho Kuriyama, Toshiyuki Ishiwata, Hiroshi Yoshida. A newly established neuroendocrine carcinoma cell line from a human ascending colon tumor shows high proliferation and CD133 expression in spherical cancer stem cell-like formation [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 6015.

Abstract 6470: Possibility of digital cytology of intraoperative ascites and lavage fluid in patients with colorectal cancer

Introduction: In patients with colorectal cancer, the results of intraoperative peritoneal cytology do not affect the prognosis. One of the reasons is the low sensitivity of peritoneal cytology. Thus, improving the sensitivity of peritoneal cytology may improve the accuracy of prognostic prediction. Digital cytology (dCytology), which detects genetic mutations in ascites or abdominal lavage fluid using digital polymerase chain reaction (PCR), is a new method by which to evaluate peritoneal cytology. In this study, we evaluated the sensitivity and clinical significance of dCytology.

Methods: We included patients with clinical T3-T4 colorectal cancer who underwent surgery from November 2018 to November 2019 in our department. In patients with ascites, ascitic fluid was collected at the start of surgery. In patients without ascites, lavage fluid was collected using 50 mL of physiological saline. Half of the liquid was used for conventional cytology, and the other half was used for dCytology. DNA was extracted from the supernatant and intraperitoneal free cells and from the cancer tissue. Circulating tumor DNA was extracted from the preoperative plasma. Digital PCR was performed on cancer tissue, supernatant DNA, intraperitoneal free cell DNA, and circulating free DNA (cfDNA) using a KRAS multi-probe.

Results: This study included 150 patients, 75 of whom had KRAS mutation in their tissues. Among them, dCytology was positive in 45 patients (60%, pStage I/II/III/IV/recurrence/unresectable: 6/22/23/16/4/4). Thirty patients had right-sided colon cancer, 20 had left-sided colon or upper rectal cancer, 7 had lower rectal cancer, and 4 had recurrent disease. Conventional cytology was positive in 11 of the 45 patients (24%), and dCytology was positive in 7 of the 11 patients. cfDNA was positive in 19 patients, and dCytology was positive in 10 of the 19. Four patients, including two patients with positive dCytology but negative conventional cytology, developed recurrence disease. Two of the four patients developed liver metastasis but no peritoneal dissemination.

Discussion: The sensitivity of dCytology was higher than that of conventional cytology. Our results suggest that tumor cells can exist in the abdominal cavity of patients with colorectal cancer. Interestingly, dCytology was positive even for patients in whom the tumor was not exposed on the outside of the colon wall (T3) and in whom the tumor was not located in the abdominal cavity (Rb).

Citation Format: Koji Ueda, Takeshi Yamada, Michihiro Koizumi, Seiichi Shinji, Akihisa Matsuda, Ryo Ohta, Goro Takahashi, Masahiro Hotta, Kohki Takeda, Keisuke Hara, Sho Kuriyama. Possibility of digital cytology of intraoperative ascites and lavage fluid in patients with 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 6470.

Clinical practice guidelines for the diagnosis and management of acute otitis media in children-2018 update

OBJECTIVE

"Clinical Practice Guidelines for the Diagnosis and Management of Acute Otitis Media in Children-2018 update (2018 Guidelines)" aim to provide appropriate recommendations about the diagnosis and management of children with acute otitis media (AOM), including recurrent acute otitis media (recurrent AOM), in children under 15 years of age. These evidence-based recommendations were created with the consensus of the subcommittee members, taking into consideration unique characteristics of bacteriology and antimicrobial susceptibilities of AOM pathogens in Japan, as well as global advances in vaccines.

METHODS

The subcommittee re-evaluated key clinical issues based on SCOPE (a master plan of the guidelines) and created clinical questions (CQ) about the diagnosis and management of AOM patients. A literature search of the publications from 2013 to 2016 were added to the Guidelines 2013, not only to assess the evidence on the effectiveness of vaccines, but also to provide up to date information of the bacteriology and antimicrobial susceptibilities of AOM causative pathogens in Japan.

RESULTS

We have proposed guidelines for disease severity-based management of AOM patients, after classifying AOM severity into mild, moderate, and severe, based on age, clinical manifestations, and otoscopic findings.

CONCLUSIONS

Precise otoscopic findings are essential for judging AOM severity, which can lead to appropriate management of AOM patients.

Abstract B43: Genetic analysis of circulating tumor cells of colorectal cancer patients captured by multiantibodies technique

Background: Accurate genetic analysis is essential for molecular therapy. Conventionally, DNA derived from tumor tissue has been the source of the gold standard of DNA information in solid tumors including colorectal cancer (CRC). However, it is well known that molecular therapy induces emerging mutations that are not found in primary tumor; thus, real-time monitoring of gene information is ideal. Circulating tumor cells (CTCs) are circulating malignant cells of solid tumor origin that are found in the bloodstream and can be a powerful candidate to play an important role. Capturing a large amount of CTCs improves the accuracy of genetic analysis of DNA derived from CTC (ctcDNA). We used 3 (EpCAM, Her2, Trop2) or 4 (EpCAM, Her2, Trop2, EGFR) antibodies to capture CTCs, and analyzed ctcDNA using next-generation sequencing (NGS).

Methods: Cohort 1: Untreated CRC patients were enrolled. Ten mL of whole blood was collected from each patient. The blood was processed using 3 antibodies (EpCAM, Her2, Trop2) and CTCs were collected. Tumor tissue was also collected from each patient. Tumor tissue DNA and ctcDNA were extracted and analyzed using NGS. Cohort 2: CRC patients, both treated and untreated, were enrolled. Twenty mL of whole blood was collected from each patient. Ten mL of the blood was processed using 3 antibodies (EpCAM, Her2, Trop2), and the remaining 10 mL was processed using 4 antibodies (EpCAM, Her2, Trop2, EGFR). The numbers of collected CTCs were counted and compared.

Results: Cohort 1: We enrolled 34 patients (stage II: n=4, stage III: n=7, stage IV: n=23). Median number of extracted CTC was 34 cells. From tumor tissue DNA, 53 mutations were detected. The most frequent mutation was within TP53 (n=18), followed by mutations in APC (n=13) and KRAS (n=12). From ctcDNA, 16 mutations, including 5 mutations which were not found in tissue DNA, were detected. The most frequent mutation was within TP53 (n=5), followed by mutations in KRAS and APC (n=4 each). Cohort 2: We enrolled 10 patients (stage II: n=1, stage III: n=1, stage IV: n=8). Using 3 antibodies, the median number of collected CTCs was 27 cells (range, 2–112). Using 4 antibodies, the median number of collected CTCs was 33 cells (range, 7–260). There were no statistically significant differences between the 2 groups (p=0.40).

Conclusions: Mutations not detected in primary tumors can be identified in ctcDNA, indicating the potential of CTCs in complementing gene analysis. The technique to capture CTCs using 3 antibodies appears to increase the detection rate and yield of CTCs. However, the present study did not show advantages of the 4-antibodies method, and future studies should investigate the best combination of antibodies to extract more CTCs with higher specificity.

Citation Format: Kohki Takeda, Takeshi Yamada, Michihiro Koizumi, Seiichi Shinji, Akihisa Matsuda, Ryo Ohta, Yasuyuki Yokoyama, Goro Takahashi, Masahiro Hotta, Takuma Iwai, Keisuke Hara, Koji Ueda, Sho Kuriyama, Hiroshi Yoshida. Genetic analysis of circulating tumor cells of colorectal cancer patients captured by multiantibodies technique [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B43.

[Consideration for Prognostic Indicators of Ovarian Metastasis of Colorectal Cancer]

Ovarian metastasis of colorectal cancer is associated with poor prognosis. Recent advances in chemotherapy may improve this prognosis. In this retrospective study, we evaluated indicators of poor prognosis for ovarian metastasis of colorectal cancer. Twenty patients, who were diagnosed with ovarian metastasis of colorectal cancer from April 2000 to December 2017, were enrolled. Oophorectomy was performed in 18 of the 20 patients. Postoperative chemotherapy was provided to 13 patients, and molecular targeting agents were administered in 5 patients. Metastases to other organs besides the ovaries, premenopausal condition, undifferentiated histologic type of the primary tumor, and no resection of ovarian metastases were identified as indicators of poor prognosis. The 3-year survival rate was 15%, and the 5-year survival rate was 0%. In conclusion, oophorectomy can improve the prognosis of patients with ovarian metastasis of colorectal cancer. However, prognostic improvement due to molecular target agents was not shown.

[Effectiveness of Chemoradiotherapy for the Treatment of Local Recurrence in Rectal Cancer-A Case Report]

Chemoradiotherapy(CRT)for locally recurrent rectal cancer can shrink the tumor and permit R0 resection; however, its effectiveness and safety have not been established. Herein, we report a case of a 60s man with locally recurrent rectal cancer invading the surrounding organs who was administered CRT followed by R0 laparoscopic-assisted abdominoperineal resection( APR). Local recurrence was detected 11 months after laparoscopic-assisted low anterior resection(pT3N0M0, pStage Ⅱ). After tumor shrinkage by CRT(capecitabine 3,000mg/day plus 45 Gy/25 Fr), laparoscopic-assisted APR was performed. The pathological findings showed a pathological complete response(pCR). The patient had not experienced recurrent disease at 6 months after the second surgery. CRT may improve the prognosis of patients with locally recurrent rectal cancer, especially those with possibly unresectable tumors.

Establishment and characterization of a novel neuroendocrine carcinoma cell line derived from a human ascending colon tumor

The incidence of rare neuroendocrine tumors (NET) is rapidly increasing. Neuroendocrine carcinoma (NEC) is a NET with poorly differentiated histological features, high proliferative properties and associated poor prognoses. As these carcinomas are so rare and, thus, affect only a small number of patients allowing for few cell lines to be derived from patient biopsies, the histological, immunohistochemical, and clinical characteristics associated with colorectal NEC and NEC in other organs have yet to be clearly defined. Herein, we describe the establishment of a novel NEC cell line (SS‐2) derived from a tumor resection of the ascending colon from a 59‐year‐old Japanese woman. The histological, electron microscopic and immunohistochemical features of chromogranin A (CgA) as well as confirmation of synaptophysin positivity in this tumor were typical of those commonly observed in surgically resected colorectal NEC. Further, the Ki‐67 labeling index of the resected tumor was >20% and, thus, the tumor was diagnosed as an NEC of the ascending colon. The SS‐2 cell line maintained characteristic features to those of the resected tumor, which were further retained following implantation into subcutaneous tissues of nude mice. Additionally, when SS‐2 cells were seeded into ultra‐low attachment plates, they formed spheres that expressed higher levels of the cancer stem cell (CSC) marker CD133 compared to SS‐2 cells cultured under adherent conditions. SS‐2 cells may, therefore, contribute to the current knowledge on midgut NEC biological function while providing a novel platform for examining the effects of colorectal NEC drugs, including CSC.

Analysis of colorectal cancer-related mutations by liquid biopsy: Utility of circulating cell-free DNA and circulating tumor cells

We recruited 56 colorectal cancer patients and compared the mutational spectrum of tumor tissue DNA, circulating cell‐free DNA (ccfDNA) and circulating tumor cell (CTC) DNA (ctcDNA) to evaluate the potential of liquid biopsy to detect heterogeneity of cancer. Tumor tissue DNA, ccfDNA, and ctcDNA were extracted from each patient and analyzed using next‐generation sequencing (NGS) and digital PCR. To maximize yields of CTC, three antibodies were used in the capture process. From 34 untreated patients, 53 mutations were detected in tumor tissue DNA using NGS. Forty‐seven mutations were detected in ccfDNA, including 20 not detected in tissues. Sixteen mutations were detected in ctcDNA, including five not detected in tissues. In 12 patients (35.3%), mutations not found in tumor tissues were detected by liquid biopsy: nine (26.5%) in ccfDNA only and three (8.8%) in ctcDNA only. Combination analysis of the two liquid biopsy samples increased the sensitivity to detect heterogeneity. From 22 stage IV patients with RAS mutations in their primary tumors, RAS mutations were detected in 14 (63.6%) ccfDNA and in eight (36.4%) ctcDNA using digital PCR. Mutations not detected in primary tumors can be identified in ccfDNA and in ctcDNA, indicating the potential of liquid biopsy in complementing gene analysis. Combination analysis improves sensitivity. Sensitivity to detect cancer‐specific mutations is higher in ccfDNA compared with ctcDNA.

Association between the severity of acquired von Willebrand syndrome and gastrointestinal bleeding after continuous-flow left ventricular assist device implantation

OBJECTIVES

Acquired von Willebrand syndrome, characterized by the reduction in von Willebrand factor (vWF) large multimers, has recently been considered as one of the causes of gastrointestinal bleeding (GIB). It remains unclear whether its haematological severity is linked with susceptibility to bleeding because the definition of the haematological severity of acquired von Willebrand syndrome has not been precisely determined. This study sought to establish a quantitative methodology to assess the haematological severity of acquired von Willebrand syndrome and to define the threshold for occurrence of GIB in patients implanted with left ventricular assist devices (LVADs).

METHODS

In total, 41 patients treated with continuous-flow LVAD implanted between 2011 and 2017 at Tohoku University Hospital were investigated. vWF large multimers were quantitatively evaluated using the 'vWF large multimer index' defined as the ratio of a large multimer proportion in total vWF derived from a patient to that from a normal control. Using this index, the amount of vWF large multimers was expressed as a percentage of its normal control value obtained with a simultaneous analysis of each time measurement.

RESULTS

Twelve (29%) patients developed GIB events during follow-up periods (median 591 days) after an LVAD implantation. The vWF large multimer index in patients with GIB was significantly lower than that in those without GIB (25.0 ± 10.3% vs 37.5 ± 17.8%, P = 0.008). Most importantly, all patients experiencing GIB exhibited a vWF large multimer index below 40%.

CONCLUSIONS

Patients with GIB exhibited a more severe loss of vWF large multimers. The vWF large multimer index may dictate the risk of GIB after an LVAD implantation.

Clinical trial registration number

UMIN000018135.

Risk Factors and Prognostic Factors of Hearing Impairment in Neonatal Intensive Care Unit-Treated Infants

BACKGROUND

Infants admitted to the neonatal intensive care unit (NICU) have a higher incidence of congenital hearing loss compared with the healthy newborn population.

OBJECTIVES

To clarify the relationship between risk factors for hearing impairment in NICU-treated infants and deterioration of the auditory brainstem response (ABR) threshold during childhood.

METHOD

We screened 1,071 high-risk infants admitted to the NICU for hearing impairment. One-hundred forty-eight infants exhibited an abnormal ABR threshold of ≥40 dB nHL. We analyzed the correlation of change in ABR threshold with risk factors for future hearing impairment.

RESULTS

Among infants treated in the NICU, 148 (13.8%) exhibited an ABR threshold of ≥40 dB nHL; 107 of these 148 (72.3%) showed hearing change in the process (102 showed improvement to normal hearing level, whereas 5 showed further deterioration). Our analysis showed that the factors contributing to the elevation of ABR threshold were oxygen administration and chromosomal aberrations.

CONCLUSIONS

Factors related to the elevation of ABR threshold were oxygen administration and the presence of chromosomal aberrations. Awareness of risk factors that are more likely to cause hearing loss in infants may aid in follow-up treatment of these children.

Liquid Biopsy for the Management of Patients with Colorectal Cancer

Liquid biopsy is a collective term that refers to the analysis of tumor-derived biomarkers isolated from biological fluids of cancer patients. Recently, many authors reported the usefulness of liquid biopsy for the management of malignancy. Summary and Key Messages: The peripheral blood of cancer patients is a pool of cells and/or cell products derived from the primary or metastatic tumor, including circulating tumor cells (CTCs), circulating free (cf) DNA or RNA, and exosomes containing proteins, nucleic acids, and lipids. CTCs are tumor cells that can be isolated from peripheral blood. Free circulating DNA with a tumor-specific mutation is called circulating tumor DNA (ctDNA). Some patients who undergo curative surgery experience recurrent disease, which can be due to the presence of minimal residual disease (MRD). Thus, MRD indicates a high risk of relapse. Detection of ctDNA or CTC after surgery is a direct proof of MRD. Molecular volume (e.g., the number of CTCs and level of ctDNA) might reflect tumor burden, thus high molecular volume may indicate poor prognosis. The most notable application of liquid biopsy in cancer is to understand spatial and temporal heterogeneities. Heterogeneity is one of the causes of refractoriness and hampers prediction of chemotherapeutic effect. Emerging mutations that are not present in primary tumors but are found in their metastases can be detected in ctDNA. Some colorectal cancer patients with wild-type RAS do not respond to epidermal growth factor receptor blockade. In a subset of these patients, RAS mutation is detected in ctDNA, indicating heterogeneity.

[Splenic Injury during Replacement of the Thoracoabdominal Aorta]

Extraperitoneal approach is commonly employed for thoracoabdominal aortic repair via Stoney incision. It is supposedly rare to encounter abdominal visceral bleeding during that procedure. However, the spleen may spontaneously adhere to the adjacent peritoneum, which could induce incidental injury to the spleen by its anterior mobilization during extraperitoneal approach. Unless we bare its potential risk in mind, bleeding from the spleen may be overlooked, which results in hemodynamic deterioration. We have experienced 3 cases of splenic injury that necessitated hemostatic maneuvers for bleeding during and just after the thoracoabdominal aortic repair.

Primary small intestinal volvulus after laparoscopic rectopexy for rectal prolapse

Primary small intestinal volvulus is defined as torsion in the absence of congenital malrotation, band, or postoperative adhesions. Its occurrence as an early postoperative complication is rare. A 40-year-old woman presented with rectal prolapse, and laparoscopic rectopexy was uneventfully performed. She could not have food on the day after surgery. She started oral intake on postoperative day 3 but developed abdominal pain after the meal. Contrast-enhanced CT revealed torsion of the small intestinal mesentery. An emergent laparotomy showed small intestinal volvulus, without congenital malformation or intestinal adhesions. We diagnosed it as primary small intestinal volvulus. The strangulated intestine was resected, and reconstruction was performed. The patient recovered uneventfully after the second surgery. To the best of our knowledge, this is the first report of primary small intestinal volvulus occurring after rectopexy for rectal prolapse. Primary small intestinal volvulus could be a postoperative complication after laparoscopy.

Hyperbaric Oxygen Therapy as Concurrent Treatment with Systemic Steroids for Idiopathic Sudden Sensorineural Hearing Loss: A Comparison of Three Different Steroid Treatments

We analyzed 356 patients with idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy and systemic steroids (n = 161), systemic steroids alone (n = 160), or intratympanic and systemic steroids (n = 35). The main outcome measure was the hearing recovery rate. The effect of other variables, including the initial averaged 5-frequency hearing level, patient age, interval between the onset of symptoms and treatment, presence of vertigo as a complication, presence of diabetes mellitus, smoking history, and presence of hypertension, on the hearing recovery rate was also evaluated. The overall hearing recovery rate was significantly higher for the patients treated with hyperbaric oxygen therapy and systemic steroids than for those treated with systemic steroids alone (p < 0.001) or systemic and intratympanic steroids (p < 0.001). The presence of vertigo negatively affected hearing recovery. Our findings suggest that hyperbaric oxygen therapy confers a significant additional therapeutic benefit when used in combination with steroid therapy for idiopathic sudden sensorineural hearing loss.

Feasibility of Neoadjuvant FOLFOX Therapy Without Radiotherapy for Baseline Resectable Rectal Cancer

BACKGROUND/AIM

The combination of oxaliplatin, leucovorin and fluorouracil (FOLFOX) has been established as postoperative adjuvant chemotherapy for stage III colon cancer. However, the safety and efficacy of neoadjuvant FOLFOX in patients with rectal cancer are still controversial. This prospective pilot study aimed to evaluate the feasibility of neoadjuvant FOLFOX therapy without radiation for baseline resectable rectal cancer (RC).

PATIENTS AND METHODS

The study included 30 patients with clinical stage II/III RC between February 2012 and December 2015. The patients were treated with six cycles of FOLFOX followed by elective surgery. The primary endpoint was the R0 resection rate. The secondary endpoints were the scheduled treatment completion rate, adverse events, pathological response and the disease-free survival (DFS) rate.

RESULTS

All the patients underwent elective R0 resection after neoadjuvant FOLFOX therapy. The completion rate of the 6-cycle regimen was 93.3% (28/30 patients). Grade 3-4 adverse events occurred in seven patients (23.3%). Pathological complete response was noted in two patients (6.7%). The 3-year DFS rate was 77.5% (95% confidence interval, 61.4%-93.7%).

CONCLUSION

Neoadjuvant FOLFOX therapy without radiation is a feasible therapeutic strategy for baseline resectable RC.

Differential selective hypothermic intercostal artery perfusion: a new method to probe spinal cord perfusion during thoracoabdominal aortic aneurysm repair

OBJECTIVE

To prevent paraplegia in patients undergoing thoracoabdominal aortic aneurysm repair, the importance of preoperative identification of the Adamkiewicz artery and reconstruction of critical intercostal artery have been advocated. Conversely, significance of collateral network for spinal cord perfusion has been recognized. We invented a new system consisting of a direct monitoring of cerebrospinal fluid temperature (CSFT) and differential selective hypothermic intercostal artery perfusion (D-HIAP).

METHODS

After exposing a critical intercostal artery, a 10-mm prosthetic graft was anastomosed in an end to side fashion. A balloon-tipped catheter was inserted into the graft to perfuse with 15 °C blood. Neighboring intercostal arteries were also perfused in the same fashion. Serial monitoring of CSFT was performed. Between January 2011 and January 2015, D-HIAP was employed in 50 patients with Adamkiewicz artery that located within a reconstructed area.

RESULTS

Significant CSFT drop was recorded after initiation of D-HIAP in 42 (84%) patients. Of those, 34 (68%) patients showed significantly lowered CSFT with D-HIAP into a single critical intercostal artery. Perfusion into plural intercostal arteries was necessary for CSFT drop in 2 cases (4%), and plural intercostal artery perfusion further enhanced CSFT drop that had been modestly achieved by single intercostal artery perfusion in 6 cases (12%). Eight (16%) patients did not exhibit a significant drop in CSFT even when D-HIAP was employed for the critical and neighboring intercostal arteries.

CONCLUSIONS

The detection of a disparity in temperature between the intrathecal space and blood generated by D-HIAP revealed individual variability in CSFT changes, which may imply a complexity in spinal cord perfusion. Intraoperative D-HIAP may help to identify a major blood supply for spinal cord perfusion and underlying collateral network.

Male sex and history of ischemic heart disease are major risk factors for anastomotic leakage after laparoscopic anterior resection in patients with rectal cancer

Background

Anastomotic leakage (AL) is the most serious and common complication of surgery for rectal cancer, and associated risk factors remain unknown despite developments in laparoscopic surgery. The present study aimed to determine risk factors for AL after laparoscopic anterior resection (AR) of rectal cancer.

Methods

This retrospective cohort study extracted information from a prospective database of all consecutive colorectal resections that proceeded at Nippon Medical School Hospital between January 2011 and December 2015 (n = 865). We identified 154 patients with rectal cancer treated by elective laparoscopic AR with anastomosis using primary double-stapling. Clinical variables and comorbidity, habits, and surgery-related variables were assessed by univariate and multivariate analyses to determine preoperative risk factors for clinical AL.

Results

The overall rate of clinical AL was 11.7% (18 of 154 patients), and 5 (27.8%) of 18 patients required revised laparotomy. Data from males were analyzed because AL occurred only in males. Univariate analysis of male patients (n = 100) significantly associated preoperative creatinine values (p = 0.03) and a history of ischemic heart disease (IHD) (p = 0.012) with AL. The frequency of AL tended to increase (p = 0.06) when patients had low AR (p = 0.06) and transanal drainage. Having AL significantly prolonged hospital stays compared with patients without leakage (36.2 vs. 11.1 days; p <  0.01). Multivariate analysis identified a history of IHD (odds ratio [OR], 4.73; 95% confidence interval [CI], 1.27–17.5; p = 0.025] as an independent risk factor for AL.

Conclusions

Male sex and a history of IHD are possible risk factors for AL after elective laparoscopic rectal cancer surgery.

Abstract 4594: Detection of colorectal cancer related gene mutations from CTC and ctDNA

[Background] It is well known that emerging mutations which is not found in the primary tumor exist in metastatic tumor and molecular therapy induce emerging mutation. Liquid biopsy, which includes circulating tumor cell (CTC) and circulating tumor DNA (ctDNA), may help detecting this spatial and temporal heterogeneity. We have reported that emerging KRAS mutation can be detected by using ctDNA (Yamada et al, Cancer Science 2016). However, mutation detection by using CTC has been difficult because enough amount of DNA cannot be extracted from CTC. Currently we have been able to collect more CTC than before, by using a new device which uses 3 antibodies (EpCAM, Her2, Trop2). In this study, we evaluated the potential to detect colorectal cancer (CRC) related gene mutations from CTC, and compared it with ctDNA.

[Methods] Cohort 1: This cohort included untreated CRC patients. Tumor tissue was collected from each patient, either by primary surgery or by colonoscopic biopsy. DNA was extracted from tumor tissue and was analyzed using Next Generation Sequencing (NGS). Ten mL of whole blood was also collected from the same patient. CTC, serum and white blood cell (WBC) was collected by using the CTC recovery machine (Ion Torrent Liquid Biopsy Instrument®). Cytokeratin positive, DAPI positive, CD45 negative cells were defined as CTC. DNA was extracted from each sample (CTC-DNA, ctDNA, WBC-DNA) and was analyzed using NGS. Cohort 2: This cohort included unresectable CRC patients with KRAS mutation in their primary tumor. All patients in this cohort were under treatment or after completion of chemotherapy. CTC and ctDNA was collected in the same method as cohort 1. KRAS mutations of CTC and ctDNA were detected by using digital PCR (dPCR).

[Results] Cohort 1: We enrolled 16 CRC patients (stage II: n=2, stage III: n=2, stage IV: n=12). A total of 30 somatic, hotspot mutations were detected from tumor tissue DNA. The median number of the detected mutation for each patient was 2 (0-4). The most frequent gene mutation was APC, followed by KRAS and TP53. In all patients, CTC was successfully collected. The median number of the CTC was 34 cells (5-94). However, only 6 somatic, mutations were detected from CTC-DNA. Conversely, 16 somatic mutations were detected from ctDNA. Cohort 2: We enrolled 14 stage IV CRC patients with KRAS mutation in their primary tumor. CTC was collected from 9 patients but not from 5 patients. In the 9 patients CTC was collected, the median number of the collected CTC was 26 cells (5-121). By dPCR, KRAS mutation was detected in 2 patients (2/14) from CTC-DNA, and 4 patients (4/14) from ctDNA.

[Conclusions] The new CTC capturing technology using 3 antibodies can improve detection rate and yield of CTC. However, in patients undergoing chemotherapy, the amount of CTC and ctDNA drastically reduces. At present, ctDNA is superior to CTC in potential to detect mutations, and dPCR is more sensitive than NGS to detect mutations.

Citation Format: Kohki Takeda, Takeshi Yamada, Michihiro Koizumi, Seiichi Shinji, Yasuyuki Yokoyama, Goro Takahashi, Masahiro Hotta, Takuma Iwai, Keisuke Hara, Hiroyasu Furuki, Eiji Uchida. Detection of colorectal cancer related gene mutations from CTC and ctDNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4594.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure

OBJECTIVES

Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution.

METHODS

The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties.

RESULTS

The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05).

CONCLUSIONS

Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.