Comparison of outcomes between symptomatic and asymptomatic patients with colorectal cancer: a propensity score-matched analysis of surgical invasiveness, medical costs and oncological outcomes

Background and aims

Whether asymptomatic patients with colorectal cancer (CRC) who are treated in hospitals show better outcomes than symptomatic patients with CRC still remains unknown. The aim of this study was to evaluate differences in clinical benefits following treatment in asymptomatic and symptomatic patients with CRC.

Methods

This study was a retrospective cohort analysis with data obtained from records. A cohort of 145 asymptomatic and 123 symptomatic patients who underwent CRC surgery between January 2009 and December 2011 was enrolled. To reduce bias in comparing outcomes, propensity score (PS) analysis was used for matching of patients in the symptomatic and asymptomatic groups based on clinicopathological factors. Surgical invasiveness, medical costs and oncological outcomes were examined by unadjusted and PS-matched analysis.

Results

Tumours in the symptomatic group were more often diagnosed in advanced stages compared with tumours in the asymptomatic group. Therefore, fewer symptomatic group patients underwent minimally invasive surgery. Short-term outcomes, including amount of blood loss, duration of postoperative hospital stay and perioperative medical costs, were significantly better in the asymptomatic group. Although overall survival was significantly better in the asymptomatic group, there was no significant difference between the groups when the patients were adjusted on the basis of PS.

Conclusions

Though this study was limited by the retrospective nature and small sample size, favourable outcomes in asymptomatic patients were due to the higher proportion of patients in this group who were diagnosed with CRC in earlier stages, due to participation in CRC screening programmes.

Abstract 5711: Gene expression profiles in BRAF V600E mutant colorectal cancer and association with SFRP2 methylation status

Background: Classification of colorectal cancer (CRC) according to gene expression profiling remains controversial with regards to their ability to stratify patients for precision therapy. Several studies have suggested that ‘stem cell like’ or ‘epithelial-mesenchymal transition (EMT)’ signature associates with poor prognosis. Meanwhile CRCs with BRAF V600E mutation have shown poor outcomes in several clinical trials, but the biological roles of BRAF mutation have not been fully elucidated.

Materials and Methods: To evaluate biological roles of BRAF mutations in CRC, we performed mRNA microarray analysis in the following three subsets; eight BRAF-mutant CRC tissues without MSI, six BRAF-mutant CRCs with MSI and five BRAF-wild type CRCs with MSI. Pathway analyses were performed by Gene Set Enrichment Analysis (GSEA). Following identification of candidate biomarkers that influence poor outcomes and associate with BRAF V600E mutation, we examined these candidate biomarkers in a cohort of 1068 CRC patients who underwent surgical resection of their primary tumor and/or metastatic lesions from 1994 to 2015 at the Okayama University Hospital.

Results: By the GSEA, prominent signatures enriched in CRCs with BRAF V600E mutation vs. wild-type were EMT-related processes (EMT and myogenesis). Additionally, CRC with BRAF V600E mutation strongly associated with inactivation of Wnt signaling and intestinal differentiation-related genes. Among the differentially expressed genes between CRCs with BRAF V600E mutation versus wild-type, Wnt-antagonist, Secreted frizzled-related proteins (SFRPs) were significantly upregulated in CRCs with BRAF V600E mutation. As SFRPs are well known to be inactivated in CRCs by promoter hypermethylation, and up to 80% of CRCs are methylated in the promoter region of the SFRP2 gene, we focused and analyzed SFRP2 promoter methylation status in 782 stage II-IV CRCs of our cohort by a modified highly sensitive assay for bisulfite DNA followed by fluorescence-based PCR, as we previously reported (JNCI 2009). SFRP2 methylation was observed in 498 (64.2%) stage II-IV CRCs. Interestingly, SFRP2 unmethylated CRCs with genetic mutation in the KRAS/BRAF genes demonstrated significantly poorer outcome in RFS compared with SFRP2 methylated CRCs with genetic mutations in the KRAS/BRAF genes (5-years RFS rate were 46.8% vs 72.1%; P = 0.015, Hazard ratio 2.06 [95% CI, 1.12 to 3.69]; P = 0.021).

Conclusion: Our results suggest that SFRP2 methylation status could be a potential prognostic biomarker for stage II-IV CRCs, especially with genetic mutations in the KRAS/BRAF genes.

Citation Format: Kazuya Yasui, Takeshi Nagasaka, Toshiaki Toshima, Takashi Kawai, Kunitoshi Shigeyasu, Yoshiko Mori, Junko Haraga, Keiichiro Nakamura, Yuzo Umeda, Hiroshi Tazawa, Ajay Goel, Toshiyoshi Fujiwara. Gene expression profiles in BRAF V600E mutant colorectal cancer and association with SFRP2 methylation status [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5711. doi:10.1158/1538-7445.AM2017-5711

Primary pancreatic-type acinar cell carcinoma of the jejunum with tumor thrombus extending into the mesenteric venous system: a case report and literature review

BACKGROUND

Although ectopic pancreatic tissue is common in the upper gastrointestinal tract, the incidence of ectopic pancreatic tissue in the jejunum is low, and malignant transformation in ectopic pancreatic tissue is rare. Furthermore, pancreatic-type acinar cell carcinoma (ACC) developing in the jejunum and ACC accompanied by tumor thrombus are extremely rare.

CASE PRESENTATION

A 78-year-old-woman presented with melena. Abdominal computed tomography images and endoscopic examination revealed a submucosal jejunal mass with tumor thrombus extending into a jejunal vein. The patient underwent a curative resection combined with a partial jejunectomy and partial pancreatectomy. Histopathological examination of the resected tissue showed tumor cells with a homogeneous acinar architecture identical to pancreatic-type ACC and tumor thrombus. Postoperatively, she was followed for 10 months and had no recurrence.

CONCLUSION

We present an extremely rare case of pancreatic-type ACC in the jejunum with extensive tumor thrombus invading into the mesenteric venous system. This type of cancer has not been reported previously but should be considered in the differential diagnosis of a jejunal mass.

Radiographic sarcopenia predicts postoperative infectious complications in patients undergoing pancreaticoduodenectomy

BACKGROUND

Recently, skeletal muscle depletion (sarcopenia) has been reported to influence postoperative outcomes after certain procedures. This study investigated the impact of sarcopenia on postoperative outcomes following pancreaticoduodenectomy (PD).

METHODS

We performed a retrospective study of consecutive patients (n = 219) who underwent PD at our institution between January 2007 and May 2013. Sarcopenia was evaluated using preoperative computed tomography. We evaluated postoperative outcomes and the influence of sarcopenia on short-term outcomes, especially infectious complications. Subsequently, multivariate analysis was used to assess the impact of prognostic factors (including sarcopenia) on postoperative infections.

RESULTS

The mortality, major complication, and infectious complication rates for all patients were 1.4%, 16.4%, and 47.0%, respectively. Fifty-five patients met the criteria for sarcopenia. Sarcopenia was significantly associated with a higher incidence of in-hospital mortality (P = 0.004) and infectious complications (P < 0.001). In multivariate analyses, sarcopenia (odds ratio = 3.43; P < 0.001), preoperative biliary drainage (odds ratio = 2.20; P = 0.014), blood loss (odds ratio = 1.92; P = 0.048), and soft pancreatic texture (odds ratio = 3.71; P < 0.001) were independent predictors of postoperative infections.

CONCLUSIONS

Sarcopenia is an independent preoperative predictor of infectious complications after PD. Clinical assessment combined with sarcopenia may be helpful for understanding the risk of postoperative outcomes and determining perioperative management strategies.

Early Chimerism After Liver Transplantation Reflects the Clinical Course of Recurrent Hepatitis C

BACKGROUND Human leukocyte antigen (HLA) mismatch is a characteristic feature of post-orthotopic liver transplantation (OLT) hepatitis C. To investigate the importance of donor HLA-restricted immune cells in post-OLT hepatitis C recurrence, we analyzed the frequency of donor chimerism and the clinical course of post-OLT hepatitis C. MATERIAL AND METHODS We analyzed peripheral blood chimerism in 11 HCV-reinfected patients with post-HLA mismatched OLT. Patients were divided into 2 groups: the OLT chronic hepatitis C (CHC) group (n=8), exhibiting active hepatitis C recurrence; and the OLT-persistently normal ALT (PNALT) group (n=3), without active hepatitis. Chimerism was analyzed by flow cytometry using donor-specific anti-HLA antibodies in peripheral blood mononuclear cells from 1-100 days after OLT. Kidney (n=7) and lung (n=7) transplant recipients were also analyzed for comparison. As immune cells from the donor liver might contribute to post-OLT chimerism, the characteristics of perfusates from donor livers (n=10) were analyzed and defined. RESULTS Donor-derived cells were frequently observed in liver and lung transplant recipients. The frequency of donor-derived cells from the B cell subset was significantly higher in peripheral blood from OLT-CHC group than in that of the OLT-PNALT group. B cells, however, were not the predominant subset in the perfusates, indicating that inflow of donor-derived cells alone did not cause the chimerism. CONCLUSIONS Chimerism of B cells is frequent in liver transplant patients with early recurrence of hepatitis C. We propose that monitoring of early chimerism could facilitate early detection of chronic hepatitis C recurrence, although we need more cases to investigate.

Syndrome of Inappropriate Antidiuretic Hormone Secretion Following Liver Transplantation

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is an extremely rare cause of hyponatremia post-liver transplantation. A 15-year-old Japanese girl with recurrent cholangitis after Kasai surgery for biliary atresia underwent successful living donor liver transplantation. Peritonitis due to gastrointestinal perforation occurred. Hyponatremia gradually developed but improved after hypertonic sodium treatment. One month later, severe hyponatremia rapidly recurred. We considered the hyponatremia's cause as SIADH. We suspected that tacrolimus was the disease's cause, so we used cyclosporine instead, plus hypertonic sodium plus water intake restriction, which improved the hyponatremia. Symptomatic hyponatremia manifested by SIADH is a rare, serious complication post-liver transplantation.

Predictive biomarkers for the efficacy of peptide vaccine treatment: based on the results of a phase II study on advanced pancreatic cancer

Background

The purpose of the present study was to explore novel biomarkers that can predict the clinical outcome of patients before treatment or during vaccination. These would be useful for the selection of appropriate patients who would be expected to exhibit better treatment outcomes from vaccination, and for facilitating the development of cancer vaccine treatments.

Methods

From a single-arm, non-randomized, human leukocyte antigen (HLA)-A-status-blind phase II trial of a vaccine treatment using three HLA-A*2402-restricted peptides for advanced pancreatic cancer (PC), we obtained peripheral blood samples from 36 patients of an HLA-A*2402-matched group and 27 patients of an HLA-A*2402-unmatched group.

Results

Multivariate analysis (HR = 2.546; 95% CI = 1.138 to 5.765; p = 0.0231) and log-rank test (p = 0.0036) showed that a high expression level of programmed death-1 (PD-1) on CD4+ T cells was a negative predictive biomarker of overall survival in the HLA-A*2402-matched group . Moreover, a high expression level of PD-1 on CD4+ T cells was a negative predictor for the induction of cytotoxic T lymphocytes (p = 0.0007). After treatment, we found that the upregulation of PD-1 and T cell immunoglobulin mucin-3 (Tim-3) expression on CD4+ and CD8+ T cells was significantly associated with a poor clinical outcome in the HLA-A*2402-matched group (p = 0.0330, 0.0282, 0.0046, and 0.0068, respectively). In contrast, there was no significant difference for these factors in the HLA-A*2402-unmatched group.

Conclusions

Our results indicate that the upregulation of PD-1 and Tim-3 expression on CD4+ and CD8+ T cells may restrict T cell responses in advanced PC patients; therefore, combination immunotherapy with blockade of PD-1 and Tim-3 to restore T cell responses may be a potential therapeutic approach for advanced PC patients.

Trial registration

Clinical-Trail-Registration: UMIN000008082.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0509-1) contains supplementary material, which is available to authorized users.

Sarcopenia and American Society of Anesthesiologists Physical Status in the Assessment of Outcomes of Hepatocellular Carcinoma Patients Undergoing Hepatectomy

Sarcopenia following liver surgery has been reported as a predictor of poor prognosis. Here we investigated predictors of outcomes in patients with hepatocellular carcinoma (HCC) and attempted to establish a new comprehensive preoperative assessment protocol. We retrospectively analyzed the cases of 254 patients who underwent curative hepatectomy for HCC with Child-Pugh classification A at our hospital between January 2007 and December 2013. Sarcopenia was evaluated by computed tomography measurement. The influence of sarcopenia on outcomes was evaluated. We used multivariate analyses to assess the impact of prognostic factors associated with outcomes, including sarcopenia. Of the 254 patients, 118 (46.5% ) met the criteria for sarcopenia, and 32 had an American Society of Anesthesiologists (ASA) physical status 3. The sarcopenic group had a significantly lower 5-year overall survival rate than the non-sarcopenic group (58.2% vs. 82.4% , p＝0.0002). In multivariate analyses of prognostic factors, sarcopenia was an independent predictor of poor survival (hazard ratio [HR]＝2.28, p＝0.002) and poor ASA status (HR＝3.17, p＝0.001). Sarcopenia and poor ASA status are independent preoperative predictors for poor outcomes after hepatectomy. The preoperative identification of sarcopenia and ASA status might enable the development of comprehensive approaches to assess surgical eligibility.

Surgical Outcome of Patients Undergoing Pancreaticoduodenectomy: Analysis of a 17‒Year Experience at a Single Center

The operative mortality and morbidity of pancreaticoduodenectomy (PD) remain high. We analyzed PD patients' clinical characteristics and surgical outcomes and discuss how PD clinical outcomes could be improved. We retrospectively reviewed the cases of 400 patients who underwent a PD between January 1998 and April 2014 at Okayama University Hospital, a very-high-volume center. We identified and compared the clinical outcomes between two time periods (period 1: 1998-2006 vs. period 2: 2007-2014). The total postoperative mortality and major complication rates were 0.75% and 15.8% , respectively, and the median postoperative length of stay (LOS) was 32 days. Subsequently, patients who underwent a PD during period 2 had a significantly shorter LOS than those who underwent a PD during period 1 (29 days vs. 38.5 days, p＜0.001). The incidence of mortality and major complications did not differ between the two periods. In our multivariate analysis, period 1 was an independent factor associated with a long LOS (p＜0.001). The improvement of the surgical procedure and perioperative care might be related to the shorter LOS in period 2 and ot the consistently maintained low mortality rate after PD. The development of multimodal strategies to accelerate postoperative recovery may further improve PD's clinical outcomes.

Phase II clinical trial of peptide cocktail therapy for patients with advanced pancreatic cancer: VENUS-PC study

We previously conducted a phase I clinical trial combining the HLA-A*2402-restricted KIF20A-derived peptide vaccine with gemcitabine for advanced pancreatic cancer (PC) and confirmed its safety and immunogenicity in cancer patients. In this study, we conducted a multicenter, single-armed, phase II trial using two antiangiogenic cancer vaccines targeting VEGFR1 and VEGFR2 in addition to the KIF20A peptide. We attempted to evaluate the clinical benefit of the cancer vaccination in combination with gemcitabine. Chemotherapy naïve PC patients were enrolled to evaluate primarily the 1-year survival rate, and secondarily overall survival (OS), progression free survival (PFS), response rate (RR), disease control rate (DCR) and the peptide-specific immune responses. All enrolled patients received therapy without the HLA-A information, and the HLA genotypes were used for classification of the patients. Between June 2012 and May 2013, a total of 68 patients were enrolled. No severe systemic adverse effects of Grade 3 or higher related to these three peptides were observed. The 1-year survival rates between the HLA-A*2402-matched and -unmatched groups were not significantly different. In the HLA-A*2402 matched group, patients showing peptide-specific CTL induction for KIF20A or VEGFR1 showed a better prognosis compared to those without such induction (P = 0.023, P = 0.009, respectively). In the HLA-A*2402-matched group, the patients who showed a strong injection site reaction had a better survival rate (P = 0.017) compared to those with a weak or no injection site reaction. This phase II study demonstrated that this therapeutic peptide cocktail might be effective in patients who demonstrate peptide-specific immune reactions although predictive biomarkers are needed for patient selection in its further clinical application.

A successful case of deceased donor liver transplantation for a patient with intrahepatic arterioportal fistula

Intrahepatic arterioportal fistula (IAPF) is a rare cause of portal hypertension that is often difficult to treat with interventional radiology or surgery. Liver transplantation for IAPF is extremely rare. We report a case of bilateral diffuse IAPF with severe portal hypertension requiring deceased donor liver transplantation (DDLT). A 51-year-old woman with no past medical history was admitted to another hospital complaining of abdominal distension and marasmus. A computed tomography scan and digital subtraction angiography indicated a massive pleural effusion, ascites, and a very large IAPF. Several attempts of interventional embolization of the feeding artery failed to ameliorate arterioportal shunt flow. As ruptures of the esophageal varices became more frequent, hepatic encephalopathy worsened. After repeated, uncontrollable attacks of hepatic coma, the patient was referred to our facility for further treatment. Surgical approaches to IAPF other than liver transplantation were challenging because of diffuse collateralization; therefore, we placed the patient on the national waiting list for DDLT. Although her Model for End-Stage Liver Disease score was relatively low, she received a DDLT 2 months after the waiting period. The postoperative course was uneventful, and the patient was discharged 44 days after her transplant. Liver transplantation may be a valid treatment option for uncontrollable IAPF with severe portal hypertension.

Tumor-specific delivery of biologics by a novel T-cell line HOZOT

“Cell-in-cell” denotes an invasive phenotype in which one cell actively internalizes in another. The novel human T-cell line HOZOT, established from human umbilical cord blood, was shown to penetrate a variety of human cancer cells but not normal cells. Oncolytic viruses are emerging as biological therapies for human cancers; however, efficient viral delivery is limited by a lack of tumor-specific homing and presence of pre-existing or therapy-induced neutralizing antibodies. Here, we report a new, intriguing approach using HOZOT cells to transmit biologics such as oncolytic viruses into human cancer cells by cell-in-cell invasion. HOZOT cells were successfully loaded via human CD46 antigen with an attenuated adenovirus containing the fiber protein of adenovirus serotype 35 (OBP-401/F35), in which the telomerase promoter regulates viral replication. OBP-401/F35–loaded HOZOT cells were efficiently internalized into human cancer cells and exhibited tumor-specific killing by release of viruses, even in the presence of anti-viral neutralizing antibodies. Moreover, intraperitoneal administration of HOZOT cells loaded with OBP-401/F35 significantly suppressed peritoneally disseminated tumor growth in mice. This unique cell-in-cell property provides a platform for selective delivery of biologics into human cancer cells, which has important implications for the treatment of human cancers.

Suspected Metallic Embolism following Endovascular Treatment of Intracranial Aneurysms

We describe a case series of suspected metallic embolism after coil embolization for intracranial aneurysms. Between January 2012 and December 2014, 110 intracranial aneurysms had been treated by coil embolization in our institution. In 6 cases, the postprocedural MR imaging revealed abnormal spotty lesions not detected on the preprocedural MR imaging. The lesions were also undetectable on the postprocedural CT scan. They were demonstrated as low-intensity spots on T1WI, T2WI, DWI, and T2*-weighted imaging. On DWI, they were accompanied by bright "halo," and on T2*-weighted imaging, they showed a "blooming" effect. In 3 of the 6 cases, follow-up MR imaging was available and all the lesions remained and demonstrated no signal changes. Although histologic examination had not been performed, these neuroradiologic findings strongly supported the lesions being from metallic fragments. No specific responsible device was detected after reviewing all the devices used for the neuroendovascular treatment in the 6 cases.

Relationship between visual field progression and baseline refraction in primary open-angle glaucoma

PURPOSE

To analyze the relationship between visual field (VF) progression and baseline refraction in Japanese patients with primary open-angle glaucoma (POAG) including normal-tension glaucoma.

PATIENTS AND METHODS

In this retrospective study, the subjects were patients with POAG who had undergone VF tests at least ten times with a Humphrey Field Analyzer (Swedish interactive thresholding algorithm standard, Central 30-2 program). VF progression was defined as a significantly negative value of mean deviation (MD) slope at the final VF test. Multivariate logistic regression models were applied to detect an association between MD slope deterioration and baseline refraction.

RESULTS

A total of 156 eyes of 156 patients were included in this analysis. Significant deterioration of MD slope was observed in 70 eyes of 70 patients (44.9%), whereas no significant deterioration was evident in 86 eyes of 86 patients (55.1%). The eyes with VF progression had significantly higher baseline refraction compared to those without apparent VF progression (-1.9±3.8 diopter [D] vs -3.5±3.4 D, P=0.0048) (mean ± standard deviation). When subject eyes were classified into four groups by the level of baseline refraction applying spherical equivalent (SE): no myopia (SE > -1D), mild myopia (-1D ≥ SE > -3D), moderate myopia (-3D ≥ SE > -6D), and severe myopia (-6D ≥ SE), the Cochran-Armitage trend analysis showed a decreasing trend in the proportion of MD slope deterioration with increasing severity of myopia (P=0.0002). The multivariate analysis revealed that baseline refraction (P=0.0108, odds ratio [OR]: 1.13, 95% confidence interval [CI]: 1.03-1.25) and intraocular pressure reduction rate (P=0.0150, OR: 0.97, 95% CI: 0.94-0.99) had a significant association with MD slope deterioration.

CONCLUSION

In the current analysis of Japanese patients with POAG, baseline refraction was a factor significantly associated with MD slope deterioration as well as intraocular pressure reduction rate. When baseline refraction was classified into four groups, MD slope in myopia groups was less deteriorated as compared to those in the emmetropic/hyperopic group.

Abstract 3172: Comprehensive analysis of intrahepatic cholangiocarcinoma based on viral infections and mutational status in the IDH1/2 and KRAS genes

Background: Intrahepatic cholangiocarcinoma (ICC) is a primary liver cancer with poor prognosis and limited therapeutic options. Recently comprehensive genetic profiles have elucidated novel fusion genes and somatic mutations. Although somatic mutations in the isocitrate dehydrogenase (IDH) and KRAS gene were frequently found in ICC, the clinical features of this malignancy with mutations in these genes remain unclear.

Materials and Methods: A cohort of 49 patients with ICC who underwent curative resection from 2000 to 2013 at Okayama University Hospital were enrolled and analyzed. KRAS (exon2), IDH1 (codon132), and IDH2 (codon172 and codon140) mutations were confirmed by Sanger sequencing. Associations between the mutational profiles of these genes and clinic-pathological features were investigated. Kaplan-Meier curves were plotted, and survival rates were compared using the log-rank analysis.

Results: KRAS mutations were observed in twelve ICC patients (24.5%, KRAS-mutant). IDH mutations were found in eight patients (16.3%); five patients harbored IDH1 mutations and three patients harbored IDH2 mutations (IDH1/2-mutant). Among three patients with IDH2 mutations, a rare IDH2 R140L was identified. One patient harbored both KRAS G12A and IDH2 R172K mutations (classified as KRAS-mutant). The rest of 30 ICCs harbored no mutation in either KRAS or IDH1/2 gene, thus categorized as Wild-type. Infection of Hepatitis B (HBV) or C (HCV) was observed in 10 ICCs (6 ICCs were HBV-positive and 4 ICCs were HCV-positive). Of 10 ICCs with viral infection, only two ICCs harbored KRAS mutations (categorized as virus-infected) and eight ICCs with viral infection harbored no mutation in KRAS and IDH1/2 genes. Finally, ICCs were divided into four subsets; viral-infected, KRAS-mutant, IDH1/2-mutant, and ‘others’). With regard to clinic-pathological features, lymph node metastasis was more frequently observed in KRAS-mutant (p = 0.039) compared with the others. IDH1/2 -mutant were more frequently observed in mass-forming type (p = 0.047). By survival analysis, 3-years survival rate was 85.7% in IDH1/2-mutant, 58.3% in the others, 36.3% in viral-infected, and 22.2% in KRAS-mutant, respectively (p = 0.05). Thus, our cohort suggests that IDH1/2, as well as KRAS mutations, have the potential to serve as prognostic biomarkers in ICC.

Conclusion: We conclude that not only viral infections, but also IDH1/2 and KRAS mutations could be potential predictive markers for the identification of good and worse prognosis in ICCs. Hence the mutational profiles of these genes provide an attractive rationale for developing a molecular signature for the development of non-invasive screening for ICCs in future.

Citation Format: Kazuya Yasui, Takeshi Nagasaka, Yuzo Umeda, Tomokazu Fuji, Fumitaka Taniguchi, Toshiaki Toshima, Keisuke Kimura, Takashi Kawai, Yoshiko Mori, Hiroshi Tazawa, Takahito Yagi, Ajay Goel, Toshiyoshi Fujiwara. Comprehensive analysis of intrahepatic cholangiocarcinoma based on viral infections and mutational status in the IDH1/2 and KRAS genes. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3172.

Abstract 510: A novel circulating cell free DNA-based assay in colorectal cancer patients during treatment with systematic chemotherapy

Introduction: Although circulating cell-free DNA (cfDNA) in blood plasma is being touted as a frontier noninvasive approaches, its clinical utility still remains questionable. The purpose of this study was to compare the efficacy of cfDNA by comparing blood CEA levels and radiological evaluation in patients with unresectable metastatic colorectal cancer (mCRC) who received systemic chemotherapy.

Experimental Procedures: In this study, we measured aberrant cancer-specific methylation in cfDNA and the concentration of cfDNA in plasma obtained following each treatment cycle of systemic chemotherapy in three patients with mCRC. To analyze aberrant cancer-specific methylation, we used a modified highly sensitive assay for bisulfite DNA followed by fluorescence-based PCR, as reported previously (JNCI 2009). This methodology can detect methylation status in eight regions, therefore both recovery score (RS) and methylation score (MS), ranged from 0-8 at a given time. We measured RS and MS two-times in each plasma specimen obtained before administration of systemic chemotherapies.

Results: In this pilot study, we examined a series of blood plasma obtained from three patients who received oxaliplatin-based chemotherapy together with molecularly-targeted agents. Despite initial tumor shrinkage in the metastases, all patients ultimately developed progressive disease (PD). Patient1 had wild-type KRAS, but had developed a sigmoid colon cancer with synchronous multiple liver and lung metastases. In contrast, Patient2 had mutant KRAS with sigmoid colon cancer and synchronous multiple liver metastasis. Both patients 1 and 2, demonstrated decreasing levels of CEA after the first-line chemotherapy, along with low methylation scores and concentration of cfDNA. Interestingly, in both patients, MS and concentration level of cfDNA increased prior to radiographic documentation of PD. Patient3 harbored BRAF V600E mutation, and a cancer in the ascending colon with systemic lymph node metastasis. Although, in this case, the tumor development progressed rapidly, similar to patients 1 and 2, MS and the concentration levels of cfDNA also increased prior to radiographic documentation of rapid PD.

Conclusions: Our novel DNA methylation and concentration-based monitoring assay is a novel methodology for capturing DNA methylation in circulating cell-free DNA in plasma, and is useful for the early identification of colorectal cancer patients who are at risk of developing PD prior to radiographic documentation.

Citation Format: Toshiaki Toshima, Takeshi Nagasaka, Yoshiko Mori, Takashi Kawai, Tomokazu Fuji, Fumitaka Taniguchi, Keisuke Kimura, Kazuya Yasui, Hiroyuki Kishimoto, Yuzo Umeda, Hiroshi Tazawa, Ajay Goel, Toshiyoshi Fujiwara. A novel circulating cell free DNA-based assay in colorectal cancer patients during treatment with systematic chemotherapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 510.

Oxidative stress balance is dysregulated and represents an additional target for treating cholangiocarcinoma

BACKGROUND

Pancreatico-biliary malignancies exhibit similar characteristics, including obesity-related features and poor prognosis, and require new treatment strategies. Oxidative stress is known to induce DNA damage and carcinogenesis, and its reduction is viewed as being favorable. However, it also has anti-infection and anti-cancer functions that need to be maintained. To reveal the effect of oxidative stress on cancer progression, we evaluated oxidative stress and anti-oxidative balance in pancreatic cancer (PC) and cholangiocarcinoma (CC) patients, as well as the effect of add-on antioxidant treatment to chemotherapy in a mouse cholangiocarcinoma model.

METHODS

We recruited 84 CC and 80 PC patients who were admitted to our hospital. Serum levels of reactive oxygen metabolites (ROM) and the anti-oxidative OXY-adsorbent test were determined and the balance of these tests was defined as an oxidative index. A diabetic mouse-based cholangiocarcinoma model was utilized to evaluate the effects of add-on antioxidant therapy on cholangiocarcinoma chemotherapy.

RESULTS

Serum ROM was higher and anti-oxidant OXY was lower in CC patients with poor outcomes. These parameters were not significantly different in PC patients. In mice, vitamin E administration induced antioxidant hemeoxygenase (HO)-1 protein expression in cancer tissue, while the number of stem-like cells increased. l-carnitine administration improved intestinal microbiome and biliary acid balance, upregulated the hepatic mitochondrial membrane uptake related gene Cpt1 in non-cancerous tissue, and did not alter stem-like cell numbers.

CONCLUSION

Oxidative stress balance was dysregulated in cholangiocarcinoma with poor outcome. The mitochondrial function-supporting agent l-carnitine is a good candidate to control oxidative stress conditions.

Expansion of epigenetic alterations in EFEMP1 promoter predicts malignant formation in pancreatobiliary intraductal papillary mucinous neoplasms

Purpose

Although limited understanding exists for the presence of specific genetic mutations and aberrantly methylated genes in pancreatobiliary intraductal papillary mucinous neoplasms (IPMNs), the fundamental understanding of the dynamics of methylation expansion across CpG dinucleotides in specific gene promoters during carcinogenesis remains unexplored. Expansion of DNA methylation in some gene promoter regions, such as EFEMP1, one of the fibulin family, with tumor progression has been reported in several malignancies. We hypothesized that DNA hypermethylation in EFEMP1 promoter would expand with the tumor grade of IPMN.

Methods

A sample of 65 IPMNs and 30 normal pancreatic tissues was analyzed. IPMNs were divided into the following three subsets according to pathological findings: 31 with low-grade dysplasia (low grade), 11 with high-grade dysplasia (high grade), and 23 with associated invasive carcinoma (invasive Ca). Mutations in the KRAS or GNAS genes were analyzed by Sanger sequencing, and methylation status of two discrete regions within the EFEMP1 promoter, namely region 1 and region 2, was analyzed by bisulfite sequencing and fluorescent high-sensitive assay for bisulfite DNA (Hi-SA). Expression status of EFEMP1 was investigated by immunohistochemistry (IHC).

Results

KRAS mutations were detected in 39, 55, and 70 % of low-grade, high-grade, and invasive Ca, respectively. GNAS mutations were observed in 32, 55, and 22 % of low-grade, high-grade, and invasive Ca, respectively. The methylation of individual regions (region 1 or 2) in the EFEMP1 promoter was observed in 84, 91, and 87 % of low-grade, high-grade, and invasive Ca, respectively. However, simultaneous methylation of both regions (extensive methylation) was exclusively detected in 35 % of invasive Ca (p = 0.001) and five of eight IPMNs (63 %) with extensive methylation, whereas 20 of 57 (35.1 %) tumors of unmethylation or partial methylation of the EFEMP1 promoter region showed weak staining EFEMP1 in extracellular matrix (p = 0.422). In addition, extensive EFEMP1 methylation was particularly present in malignant tumors without GNAS mutations and associated with disease-free survival of patients with IPMNs (p < 0.0001).

Conclusions

Extensive methylation of the EFEMP1 gene promoter can discriminate invasive from benign IPMNs with superior accuracy owing to their stepwise accumulation of tumor progression.

Electronic supplementary material

The online version of this article (doi:10.1007/s00432-016-2164-x) contains supplementary material, which is available to authorized users.