Extracorporeal cardiopulmonary resuscitation-based approach to refractory out-of-hospital cardiac arrest: A focus on organ donation, a secondary analysis of a Prague OHCA randomized study

BACKGROUND

Refractory out-of-hospital cardiac arrest (OHCA) has a poor outcome. In patients, who cannot be rescued despite using advanced techniques like extracorporeal cardiopulmonary resuscitation (ECPR), organ donation may be considered. This study aims to evaluate, in refractory OHCA, how ECPR versus a standard-based approach allows organ donorship.

METHODS

The Prague OHCA trial randomized adults with a witnessed refractory OHCA of presumed cardiac origin to either an ECPR-based or standard approach. Patients who died of brain death or those who died of primary circulatory reasons and were not candidates for cardiac transplantation or durable ventricle assist device were evaluated as potential organ donors by a transplant center. In this post-hoc analysis, the effect on organ donation rates and one-year organ survival in recipients was examined.

RESULTS

Out of 256 enrolled patients, 75 (29%) died prehospitally or within 1 hour after admission and 107 (42%) during the hospital stay. From a total of 24 considered donors, 21 and 3 (p = 0.01) were recruited from the ECPR vs standard approach arm, respectively. Fifteen brain-dead and none cardiac-dead subjects were ultimately accepted, 13 from the ECPR and two from the standard strategy group. A total of 36 organs were harvested. The organs were successfully transplanted into 34 recipients. All transplanted organs were fully functional, and none of the recipients died due to graft failure within the one-year period post-transplant.

CONCLUSION

The ECPR-based approach in the refractory OHCA trial is associated with increased organ donorship and an excellent outcome of transplanted organs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01511666. Registered January 19, 2012.

Intraoperative Imaging in Hepatopancreatobiliary Surgery

Hepatopancreatobiliary surgery belongs to one of the most complex fields of general surgery. An intricate and vital anatomy is accompanied by difficult distinctions of tumors from fibrosis and inflammation; the identification of precise tumor margins; or small, even disappearing, lesions on currently available imaging. The routine implementation of ultrasound use shifted the possibilities in the operating room, yet more precision is necessary to achieve negative resection margins. Modalities utilizing fluorescent-compatible dyes have proven their role in hepatopancreatobiliary surgery, although this is not yet a routine practice, as there are many limitations. Modalities, such as photoacoustic imaging or 3D holograms, are emerging but are mostly limited to preclinical settings. There is a need to identify and develop an ideal contrast agent capable of differentiating between malignant and benign tissue and to report on the prognostic benefits of implemented intraoperative imaging in order to navigate clinical translation. This review focuses on existing and developing imaging modalities for intraoperative use, tailored to the needs of hepatopancreatobiliary cancers. We will also cover the application of these imaging techniques to theranostics to achieve combined diagnostic and therapeutic potential.

Multilocular infection caused by hypervirulent Klebsiella pneumoniae

Hypervirulent strains of Klebsiella pneumoniae (hvKP) can cause atypical multilocular infections in otherwise healthy patients. Diagnosis of infection caused by hvKP is based mainly on clinical findings and laboratory results, including detection of virulence genes. It typically manifests as hepatic abscess with metastatic spread. Treatment is based on surgical intervention in combination with targeted antimicrobial therapy. The occurrence of hvKP infection is relatively common in Asia, and while still rare in Europe, incidence is increasing. The article aims to provide a short overview of the issue and increase awareness of the possible occurrence of hvKP infections.

Coronary flow reserve can explain some of FFR and iFR discrepancies. Results from international, multicenter and prospective trial

Background

The trial collected prospective data from physiology measurements of borderline lesions in five Czech, one Japan and one Argentinian cathlabs. The main purposes were to analyze diagnostic agreement between FFR (fractional flow reserve) and iFR (instantaneous wave free ratio) examinations and to find possible explanations for discrepant results.

Methods

FFR and iFR examinations were analyzed using Philips-Volcano console and coronary flow reserve (CFR) was analyzed by using Combomap machine Philips-Volcano. Hyperemia for FFR and CFR measurements was induced by intracoronary administration of adenosine. We used CFR as a truth for comparison between FFR and iFR, because CFR has higher impact on patients prognosis than pressures indices.

Results

Data were collected from February 2016 to June 2019 and the database includes 1.789 examinations from 1.492 patients (282 of them, 15.8%, with ACS). CFR were measured in 343 lesions in 293 patients. (ACS 31.2%). Overall correlation between FFR and iFR is high (R=0.86 p<0.0001). The FFR/iFR discrepancy occurred in 84 measurements (24.5%), more frequently it was FFRp (positive) / iFRn (negative) type of discrepancy (65, 18.9%) compare to FFRn/iFRp (19, 5.5%) one. There was no difference in occurrence of FFR/iFR discrepancy in stable patients and ACS ones (25.1%vs. 22.4%, p=0.59). The CFR correlated better with iFR than with FFR (R=0.56, p<0.0001 vs. R= 0.36, p<0.0001) (see table). In lesions with FFRp/iFRn type of discrepancy we found substantially higher CFR value compared to FFR/iFR agreement group (2.4±0.7 vs. 1.5±0.5, p<0.0001). Unlike to FFRn/iFRp discrepancy, where CFR value was similar with agreement group (1.4±0.1 vs. 1.5±0.1, p=0.25)

Conclusion

The FFR/iFR discrepancy occurred in almost one quarter of examinations. Correlation between CFR and iFR is better than between CFR and FFR. High flow is probably one of the main reason for FFRp/iFRn type of discrepancy.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Czech Health Research Council

Abstract 724: Application of oncoMonitor™ ctDNA tracking technology for monitoring of therapy and early detection of recurrence in metastatic colorectal cancer

Introduction: Liquid biopsy based on detection of circulating tumor DNA (circulating-tumor DNA, ctDNA) is finding new applications in clinical management of solid cancers. From the initial use as an alternative to classical tissue biopsy for investigation of molecuar profiles in prediction or resistance detection of targeted therapies the approach is now applied to monitoring of minimal residual disease (MRD). Patients with metastatic colorectal cancer undergoing liver resection are subject to standard post-operative surveillance based mainly on periodic CT or PET/CT imaging (complemented eventually by MR imaging). Some reports have previously demonstrated benefit from performing a ctDNA detection complimentary to standard imaging to improve follow-up efficiency.

Methods: In this report we demonstrate use of our oncoMonitor™ ctDNA technology, based on detection of somatic mutations derived from tumor in patient plasma. Unlike various approaches targeting oncogenic hotspot mutants, this technology can trace virtually any somatic mutation found in any gene (e.g. a tumor supressor). The relatively simple approach is based on rapid scanning of 100 to 140bp target amplicons for presence of mutations revealed based on differential melting by high-resolution denaturing capillary electrophoresis (DCE). The detection sensitivity is 0.1% MAF.

Patients: In our concordance study during which a total of 41 patients with metatatic colorectal cancer were followed for 3 years from metastasectomy. oncoMonitor™ tast was applied to evaluate ctDNA along with standard CT or PET/CT imaging and tumor markers (CEA/CA19-9).

Results: A total of 23 recurrences were clinically confirmed during surveillance. All recurrences were detected by oncoMonitor™ (23/23, 100%), while at the same time only 17 instances were detected by CT or PET/CT imaging (17/23, 73.9%) and 16 by tumor markers CEA/CA19-9 (16/23, 69.6%). There were 2 patients after R0 resection with persistent ctDNA positivity who had recurrence within 6 months from surgery.

Conclusions: oncoMonitor™ technology is suitable for quick and sensitive detection of ctDNA in plasma of patients with metatatic colorectal cancer after liver resection. Evaluation of ctDNA presence improves efficiency of post-operative surveillance. Supported by Czech Ministry of Health project no. 17-31909A.

Citation Format: Marek Minarik, Barbora Belsanova, Renata Ptackova, Tereza Halkova, Filip Pazdirek, Jiri Pudil, Miroslav Levy, Jaromir Simsa, Jiri Hoch, Miroslav Ryska, Lubos Petruzelka, Lucie Benesova. Application of oncoMonitor™ ctDNA tracking technology for monitoring of therapy and early detection of recurrence in metastatic 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 724.

Circulating tumor DNA as a biomarker in metastatic colorectal carcinoma case report

INTRODUCTION

Colorectal cancer (CRC) is the third most common malignant disease worldwide. The stage of the disease at the time of diagnosis and the capture of an early recurrence have a direct impact on long-term survival. Existing control screening methods often do not reflect real-time metastatic disease. In patients with detectable circulating tumor DNA (ctDNA), liquid biopsy can be an effective monitoring tool.

CASE REPORT

In 2012, we performed sigmoid resection in a 57 years old patient for advanced CRC. The follow-up assessments included: blood samples for CA 19-9 and CEA, endoscopy and imaging methods. We also sampled peripheral blood to determine the level of ctDNA. Its value corresponded to the development of the disease throughout the period. Twice it outperformed imaging methods. CEA showed some degree of unreliability, especially after prolonged illness. CA 19-9 was in the normal range at all times.

CONCLUSION

Circulating tumor DNA is an effective tool in the diagnosis of recurrent metastatic CRC. In patients with detectable ctDNA, its level correlates with the tumoral mass in real time. It has a predictive value in monitoring the treatment response. Its implementation in the follow-up of patients with CRC may have an impact on the choice of treatment strategy and consequently on patient survival.

Portal vein ligation with alcohol injection - our first experiences

INTRODUCTION

Surgical resection of colorectal liver metastases is a gold standard treatment. The indication criteria still continue expanding. The future liver remnant volume (FLRV) remains the only limiting factor of the resection. Many methods have been discussed to increase the FLRV. Injection of absolute alcohol into the portal vein seems to be one of the most effective.

PATIENTS AND METHODS

In 2018 we perioperatively injected 25 ml of absolute alcohol into the ligated right portal branch in 3 patients with colorectal liver metastases at our department. All patients were indicated for second-stage right hemihepatectomy.

RESULTS

The mean FLRV increase was 206.6 cm3 46 weeks after absolute alcohol injection. A transient elevation of transaminases was observed with spontaneous regression within 10 days from alcohol injection. There was no complication clearly associated with alcohol application. No liver failure was observed. No patient died. All three patients underwent second-stage right hemihepatectomy.

CONCLUSION

Portal vein ligation with alcohol injection can be an uncomplicated and highly effective method to achieve FLRV hypertrophy.

Abstract 405: Using a ctDNA liquid biopsy assay for post-surgical serial monitoring and early detection of disease progression in advanced colorectal cancer patients

Introduction: ctDNA liquid biopsy has been recognized as a useful approach to monitor effect of ongoing cancer treatment. The ctDNA dynamics is reflecting the overall tumor burden. Here we present a utility of a simple ctDNA assay for longitudinal monitoring of patients with advanced stages of colorectal cancer in conjunction with surgical treatment.

Patients and Methods: In a prospective setting the disease course of a total of 121 patients in Stage III and IV of colorectal cancer was monitored by ctDNA. A panel of somatic mutations was initially screened in primary and/or metastatic tissue. The found mutations were then traced in ctDNA from plasma acquired before surgery and during the subsequent days and months. In a subgroup of rectal cancers ctDNA was also analyzed prior and during the neoadjuvant chemoradiotherapy. The ctDNA levels were then correlated to the clinical parameters such as surgical radicality, disease relapse or response to anticancer therapy.Results: A brief overview of the ctDNA data is shown in Table I.

TABLE I:ctDNA status in patients monitored in this studyTime of plasma samplingctDNA negativectDNA positivesample not availableprior to surgery309102 - 7 days after surgery30 (56%)24 (44%)373 months after surgery18 (54%)15 (46%)216 - 9 months after surgery8 (42%)11 (58%)1412 - 14 months after surgery4 (31%)9 (69%)418 - 24 months after surgery2 (28%)5 (72%)6

A high correlation between the surgical radicality and appearance or absence of ctDNA after surgery was confirmed with 22 of 24 patients with R0 resection as ctDNA negative and 22 of 30 patients with R1/R2 resection as ctDNA positive. Of the 30 ctDNA-negative patients following surgery, 4 patients had ctDNA-detectable progression during the first 9 months and 12 during the next 14 months. At 4 occasions the ctDNA has outperformed CT imaging in detecting the progression. The anti-angiogenic therapy resulted in disappearance or decrease of ctDNA levels in 6 patients during the first month of treatment. In a subgroup of rectal cancers, neoadjuvant chemoradiotherapy resulted in rapid decrease of ctDNA already in the first week of administration. Conclusion: The ctDNA dynamics closely follows clinical course of disease and may serve as a useful biomarker in post-operative follow-up. (supported by AZV 15-27939A)

Citation Format: Marek Minarik, Tereza Halkova, Anastasiya Semyakina, Barbora Belsanova, Jiri Pudil, Filip Pazdirek, Miroslav Levy, Jaromir Simsa, Miroslav Hoch, Miroslav Ryska, Lucie Benesova. Using a ctDNA liquid biopsy assay for post-surgical serial monitoring and early detection of disease progression in advanced colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 405.

Multidisciplinary team in colorectal cancer treatment - analysis of our patients in 2017

INTRODUCTION

Multidisciplinary teams (MDTs) have become a standard part of treating oncological patients. Based on the available data, they have lead to significantly higher survival rates in the treatment of colorectal cancer (CRC). Reported negatives include potentially longer times between diagnoses and the start of appropriate treatment, and the lack of quality controls over the MTDs actions. This report aims to assess the benefits of MDTs using our own data set for 2017.

METHODS

Year 2010 saw the institution of an MDT at the Central Military University Hospital in Prague, with the obligation to refer CRC patients to the MDT before the start of treatment. Having standardized the registration, we have implemented a simple procedure to track the quality of our MDTs involvement and its patient benefits: number of patients, number of referrals with proposed diagnostic and therapeutic procedure, frequency and reason of changes to original strategies, and the frequency of variations from the MDTs conclusions.

RESULTS

405 CRC patients were referred to the MDT in 2017; we have found 499 referrals in this group. The data set was formed predominantly by men (61%), with the mean age of 63 (21-91), and the median age of 64.5 years. Surgical treatment was the most commonly proposed procedure (59%), followed by systemic treatment or, as the case may be, radiotherapy. In 24% of the cases, the conclusion did not match the originally proposed procedure. The decision not to go through with the proposed surgical treatment was the most common change (66 %). We have found a difference in the quality of referral in patients examined specifically by the referring doctor, as opposed to patients whose medical records have just been sent in. We have found therapeutic variation in the MTDs conclusions in less than 5% of patients.

CONCLUSION

Having analyzed our data for CRC patients referred to the MDT in 2017, we have found out that in 24% of the patients, the MDT referral leads to a change in the originally proposed diagnostic and therapeutic procedure. Consensus among the MDTs members on the CRC patients treatment guarantees an optimum procedure. What is fundamental is that the referring doctor knows the patient. Constant tracking of the MDTs outputs forms a condition for sustaining the quality of its work and a base for assessing its benefits to the patients.

Abstract 3139: Liquid biopsy (ctDNA) testing in clinical management of solid cancers: 5-years of experience

Background: Detection and profiling of circulating tumor DNA (ctDNA) is an attractive tool for management of cancer patients, in particular for early detection of the relapse after surgery or monitoring of response to systemic therapy. The main advantage is minimal invasivity and applicability to a wide range of solid cancers. Methodologies are based on digital PCR with the limit of detection (LOD) below 0.01% mutated alleles, however, these often require significant amounts of input DNA (10s to 100s of ng). In the present work we demonstrate routine detection and clinical utility of ctDNA in a cohort of 423 patients covering a range of 5 different solid tumors.

Methods: ctDNA is detected by somatic mutations found in primary tumor tissue by applying a specific mutation panel targeted to the tumor tape. Detection was done by denaturing capillary electrophoresis (input DNA at concentrations of 5 pg, LOD 0.03 - 1%). The cohort included samples from 257 colorectal cancer patients (CRC), 97 patients with ductal adenocarcinoma of the pancreas (PDAC), 32 patients with non-small cell lung cancer (NSCLC), 12 patients with gastric adenocarcinoma (GA) and 6 patients with head and neck cancers (HNC). A longitudinal monitoring of ctDNA levels prior to surgery, a week after surgery and at three-month follow-up intervals, was performed in 16 CRC patients. Overall ctDNA detection rate, radicality of resection, disease recurrence, tumor dynamics and survival prognosis were evaluated.

Results: ctDNA rates were at 32% for NSCLC, 31% for CRC, 30% for GA, 25% for PDAC and 25% for HNC. When looking at a subgroup of patients in Stage IV of the disease the rates increased to 53% for NSCLC, 77% for CRC, 50% for GA, 46% for PDAC and 50% for HNC. 14 out 16 CRC patients with R0 resection remained ctDNA negative (88%), two patients dropped out of the study. Follow-up monitoring lead to detection of progression in 9 out of 13 patients (69%). In 3 patients (23%), ctDNA positivity preceded standard detection by CT scan. In 5 patients with follow-up exceeding 1 year (5 to 10 sample acquisitions over 15 to 28 month period) the ctDNA levels correlated with the clinical course of the disease (progression/stabilization/remission). There was a borderline statistically significance for prognostic role of ctDNA presence in PDAC patients with 140 days vs. 200 days (P = 0,0519, long-rank test) for ctDNA positive and negative, respectively.

Conclusion: We have introduced a ctDNA method to routine management of 5 different solid cancers. Our results indicate clinical utility for resection radicality confirmation as well as early detection of disease progression and tumor dynamics in CRC patients. The same is applicable to approx. 50% of patients with advanced GA, NSCLC and HNC. CtDNA positivity may also indicate a negative prognosis for PDAC patients. Supported by IGA MZ grant no. NT 13660.

Citation Format: Lucie Benesova, Barbora Belsanova, Tereza Halkova, Jiri Pudil, Bohus Bunganic, Milos Pesek, Bretislav Gal, Miroslav Zavoral, Miroslav Ryska, Marek Minarik. Liquid biopsy (ctDNA) testing in clinical management of solid cancers: 5-years of experience. [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 3139.

[Bile leakage after liver resection: A retrospective cohort study]

INTRODUCTION

Many previous reports have focused on bile leakage after liver resection. Despite the improvements in surgical techniques and perioperative care the incidence of this complication rather keeps increasing. A number of predictive factors have been analyzed. There is still no consensus regarding their influence on the formation of bile leakage. The objective of our analysis was to evaluate the incidence of bile leakage, its impact on mortality and duration of hospitalization at our department. At the same time, we conducted an analysis of known predictive factors.

METHOD

The authors present a retrospective review of the set of 146 patients who underwent liver resection at the Department of Surgery of the 2nd Faculty of Medicine of the Charles University and Central Military Hospital Prague, performed between 20102013. We used the current ISGLS (International Study Group of Liver Surgery) classification to evaluate the bile leakage. The severity of this complication was determined according to the Clavien-Dindo classification system. Statistical significance of the predictive factors was determined using Fishers exact test and Students t-test.

RESULTS

The incidence of bile leakage was 21%. According to ISGLS classification the A, B, and C rates were 6.5%, 61.2%, and 32.3%, respectively. The severity of bile leakage according to the Clavien-Dindo classification system - I-II, IIIa, IIIb, IV and V rates were 19.3%, 42%, 9.7%, 9.7%, and 19.3%, respectively. We determined the following predictive factors as statistically significant: surgery for malignancy (p<0.001), major hepatic resection (p=0.001), operative time (p<0.001), high intraoperative blood loss (p=0.02), construction of HJA (p=0.005), portal venous embolization/two-stage surgery (p=0.009) and ASA score (p=0.02). Bile leakage significantly prolonged hospitalization time (p<0.001). In the group of patients with bile leakage the perioperative mortality was 23 times higher (p<0.001) than in the group with no leakage.

CONCLUSION

Bile leakage is one of the most serious complications of liver surgery. Most of the risk factors are not easily controllable and there is no clear consensus on their influence. Intraoperative leak tests could probably reduce the incidence of bile leakage. In the future, further studies will be required to improve the perioperative management and techniques to prevent such serious complications. Multidisciplinary approach is essential in the treatment.

["Liver fist approach" in the management of synchronous liver metastases from colorectal cancer: Preliminary non-randomized study results]

INTRODUCTION

Liver metastases are diagnosed in 60% of patients with colorectal cancer, both at the time of diagnosis or later in the course of their management. Surgical treatment is the sole potentially curable method with 5-year overall survival of approximately 50%. However, only less than 20% of patients underwent liver resection. A joint effort of medical oncologists and surgeons is to increase the numbers of resected patients. The "liver first approach" (LFA) is one of approaches aimed at increasing resecability. The authors present their preliminary results using this method.

METHODS

102 patients were included in the multicentre study supported by the grant IGA NT 13660 Evaluation of quality of multimodal treatment for patients with colorectal cancer liver metastases - conducted at the Central Military Hospital between September 2012 and January 2015. We used LFA in 12 patients (12%). Patients were indicated for liver resection based on good response to neoadjuvant systemic therapy. Multiple bilobar liver involvement (>4 metastases) was present in 11 cases and one large solitary metastasis in the right liver lobe in one case. The primary tumor was located in the rectum in 9 patients, in the rectosigmoid in 3 patients; 3 patients had a colostomy. Others showed no signs of bowel obstruction.

RESULTS

We have performed R0 resections in 11 cases, and two-stage hepatectomy with portal vein embolisation was indicated 3 times (in one case we did not finish the second stage due to quick progression after PVE). We performed major resections 7 times, along with sever extraanatomic resections, incl. 11 RFA (6 times in combination with major resections). Perioperative mortality was 0%, morbidity 33% (Dindo-Clavien >2). Ten patients underwent adjuvant chemotherapy, in 7 cases including radiotherapy of the small pelvis due to a local advanced primary tumor. Resection of the primary tumor was done in 7 patients (58%). Two patients died recently because of disease progression (17%); progression was observed in 6 patients (50%).

CONCLUSION

We deem the LFA suitable especially for patients with metastatic rectal tumors where adjuvant systemic therapy can be combined with radiotherapy. The timing of the resection of the primary tumor still remains a question: it is necessary to rule out potential recurrence of liver metastases, which affected more than 50% of the patients. The benefit of LFA must be confimed by randomised studies.

[Da Vinci assisted surgery for rectal cancer - preliminary results of nonrandomized trial]

INTRODUCTION

The incidence of colorectal cancer (CRC) in the Czech Republic is reported to be one of the highest on the global scale. Radical tumor removal has been observed to be the most effective part in the context of current multimodal therapy. The authors present their preliminary results of robotic assisted treatment of rectal carcinoma (RC).

METHOD

The observed group includes 61 patients who underwent robotic assisted treatment for rectal cancer. The data were collected prospectively in the last 31 patients. Analyses were conducted on epidemiological data, perioperative outcomes, complications and oncological results.

RESULTS

Robotic assisted treatment of RC was performed in 61 patients: 34 men and 27 women, mean age of 62 years (33-80). Neoadjuvant oncological treatment was indicated in 46% of the patients. Average blood loss was 187 ml, transfusions were administered in three cases. Conversion to open procedure was performed 6 times, and 16 patients had postoperative complications. Anastomotic leak was observed in 10% of the patients, and 4 patients undewent surgical treatment. No patient died. Local recurrence of the cancer was diagnosed in 3 (5%) patients. The quality of mesorectal excision (ME) and the circumferential resection margin [(y)pCRM] have been determined in 27 patients since 2013. Positive (y)pCRM was recorded in two cases and incomplete ME was observed in 25.8% of the patients.

CONCLUSION

Surgical treatment for RC is pivotal in multimodal therapy. Our preliminary results are similar to the conclusions in other published studies. The da Vinci robotic system is a safe manipulator in the treatment of RC and provides indisputable benefits to the surgeon when operating in the narrow pelvic space. However, the benefits of robotic treatment in abdominal surgery are yet to be evaluated in patients (with respect to long-term results, sufficient number of patients or a high EBM level of evidence). The high purchase price of the robotic device, individual instruments with equipment and non-systemic compensation constitute a significant hindrance that prevents wider use of the robotic system in the treatment of RC and other abdominal malignancies in the Czech Republic.

Abstract 2406: Validation of a simple low-cost method to monitor ctDNA in patients with solid cancers

Background: Detection of circulation tumor DNA (ctDNA) in plasma has become a viable option for non-invasive monitoring of patients. Also termed “liquid biopsy” the approach is applicable for pre-diction of response and prediction of resistance to biological therapy (1, 2). Various techniques have been used for ctDNA detection, frequently employing clonal amplification on a digital PCR format (3) with limits of detection (LOD) below 0.01% of mutant alleles. However, these techniques suffer from high complexity, expensive instrumentation, and a considerable cost per sample. We hereby present a simple low-cost alternative that is implementable to routine ctDNA testing.

Methods: A panel of PCR amplicons (106 - 174bp) was resolved by denaturing capillary electrophoresis (DCE) revealing minute presence of mutation specific hetero-duplexes. The final panel consisted of clinically relevant oncogenic mutations KRAS, NRAS, BRAF, PIK3CA and EGFR as well as cancer-related mutations in tumor suppressors TP53, APC and CTNNB1. A total of 299 patients was subsequently examined for presence of ctDNA in plasma including 194 with colorectal cancer (CRC), 26 with NSCLC and 79 with pancreatic cancer (PanC). CtDNA status was correlated to TNM stage and tumor markers (CEA and Ca19-9). In a subset of CRC patients (n = 20) the ctDNA was monitored in 2 - 6 month intervals and correlated to the therapy response.

Results: The experimental LOD value was in the range between 0.03 - 1% for all tested mutations within the panel. A minimum input amount of DNA was 5 pg (0,005 ng).. The overall rate of ctDNA detection was 32% for CRC (stages I - IV), 31% for NSCLC (stages III - IV) and 27% for PanC (stages II - IV). The highest detection rate, 69%, was observed in Stage IV CRC patients. Comparison with tumor markers (TM) revealed 62% of cases positive for both TM and ctDNA and 13% TM-negative cases with ctDNA positivity. Post-operative absence or persistence of ctDNA was related to the radicality of the surgical treatment and the ctDNA levels were concordant with the response to adjuvant chemotherapy. In several patients a disease progression was signalized based on ctDNA even prior to actual clinical detection by CT imaging.

Conclusion: DCE is a simple technique applicable for detection of ctDNA in cancer patients without a need for costly hardware/software equipment. The detection rates are 10 - 15% lower compared to the dedicated dPCR techniques, however, the method requires ca 100x less input DNA, the cost per patient is about 10-fold lower and the turnaround time per test is under 5 hours.

Supported by the Czech Ministry of Health Grant 14383.

Literature

1. Bettegowda C et al. Sci Transl Med. 2014,6(224):224ra24

2. Douillard JY et al. J Thorac Oncol. 2014, 9(9):1345-1353.

3. Benesova L et al. Anal Biochem 2013,433(2):227-234.

Citation Format: Lucie Benesova, Barbora Belsanova, Petra Minarikova, Tereza Halkova, Jiri Pudil, Filip Pazdirek, Milos Pesek, Ondrej Fiala, Jiri Hoch, Miroslav Zavoral, Bohus Bunganic, Miroslav Levy, Ludmila Lipska, Lubos Petruzelka, Miroslav Ryska, Marek Minarik. Validation of a simple low-cost method to monitor ctDNA in patients with solid cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2406. doi:10.1158/1538-7445.AM2015-2406

Pylephlebitis in patient with covered perforated rectosigmoid cancer

Acute portal vein thrombosis and septic thrombophlebitis of the portal vein represent serious, although rare cases in the non-cirrhotic population. The authors present a case report, in which nonspecific clinical and CT scan findings led to the difficult diagnosis of pylephlebitis due to perforated rectosigmoid cancer.

[The benefit of the da Vinci robotic system in abdominal oncosurgery - our preliminary results]

INTRODUCTION

The robotization of minimally invasive treatment in surgery has been evident since the beginning of the third Millennium. The authors present their current evaluation of the benefits of the da Vinci robotic system in the treatment of abdominal malignancy.

MATERIAL AND METHODS

The authors summarize published studies in the Medline and Pubmed databases that compare robotic, laparoscopic and open approaches in the treatment of abdominal malignancy. Epidemiological data, intraoperative blood loss, complications and oncological outcomes are monitored in a group of 30 patients with carcinoma of rectum.

RESULTS

The results measured in the evaluated parameters (open conversion, perioperative and non - surgery complications, intraoperative blood loss, histological findings, lethality) are similar in the published studies, i.e. without significant differences in both groups subject to the robotic and laparoscopic treatment. The operative time in the group of robotic surgery has been is slightly longer (a non-significant difference) in most of published studies. 30 patients underwent the robotic assisted treatment of the carcinoma of the rectum (14 men and 16 women, average age of 60 years (33-80). Neoadjuvant treatment was indicated in 50% of the patients. Average blood loss was 260 ml, transfusion was administered in one case. Conversion to laparotomic treatment was performed twice, four patients had post-operative complications, no patient has died. We have not found any relapse of oncological disease in the observed set to this date.

CONCLUSION

The Da Vinci robotic system is a safe manipulator in the treatment of abdominal malignancy (including HPB surgery). Randomized clinical trials (RCT) have confirmed (short-term clinical and oncological) results comparable to the laparoscopic or open approach treatment. The benefits of robotic surgery for patients in abdominal surgery (long-term results, sufficient number of patients and high-grade EBM) are yet to be evaluated, however. It is necessary to implement more randomized clinical trials going forward. Our preliminary results are similar to the results reached in other, published studies.

[Biliary complications after major liver resection]

INTRODUCTION

Major liver resection involves operations where three or more liver segments are resected. The decrease of perioperative and early lethality enlarged indicator conditions, especially in patients with colorectal cancer liver metastasis. Bile leakage belongs to major postoperative complications.

AIM

Authors present literary experience and retrospective analysis of patients with emphasis on biliary complications and their treatment.

RESULTS

96 patients underwent major hepatic resections between April 2004 and December 2009 at the Surgery Department of the Central Military Hospital in Prague. The average age of patients was 61 (25-84). Patients with an oncology disease dominated the set, representing 78% of all the patients. One half of the patients were formed by patients with colorectal cancer liver metastasis. Fourteen patients (14.6%) suffered from postoperative biliary complications. Non-surgical treatment was successful in nine cases. Surgical treatment was necessary in five cases. Combinations of these methods were essential in half of the patients. Two patients died (2.1%).

CONCLUSION

Bile leakage after major liver resection is a quite common and serious postoperative complication. Conservative treatment (ERCP, CT - navigated drainage) is the method of choice. Surgical treatment is necessary where conservative management fails or where the size of the bile leakage is large. Multidisciplinary approach to treatment of these patients is essential.

[Multidisciplinary cooperation in the management of serious bleedings complicating necrotizing pancreatitis--a case review]

Acute necrotising pancreatitis is connected with a high complication rate. The most serious ones are hemorrhagic complications with bleeding from vascular structures erosions. Authors report a case of endovascular treatment of surgically untreatable lesion of portal vein. In this case stentgraft was successfully implanted to cover the erosion and stop the bleeding. Percutaneous transhepatic route was used.

[Treatment of hepatocellular carcinoma and current situation in the Czech Republic]

Hepatocelullar carcinoma (HCC) is the commonest primary liver malignacy. Its incidence is increasing worldwide. In the Czech Republic, about 250 new cases are reported per year. The patient's prognosis depends on early diagnosis and initiation of a correct therapeutical procedure. During the decision making process, tumor staging, as well as the chronic liver disease stage, must be considered. Surgery, i.e. liver resection or transplantation, is the only potentially curable method. Other treatment options include chemoembolization, radiofrequency ablation, alcoholization and, currently poorly effective systemic chemotherapy. Current monitoring of the radical procedures in the Czech Republic is unsatisfactory. Although surgical treatment has been performed by many clinics, based on the available data, none of the following could be assessed: the number of surgically managed HCC patients in the Czech Republic per year, disease staging in these patients and their short-term and long-term treatment outcomes. In the Czech Republic, 45 liver transplantations have been performed, data on resection procedures are not available. The aim of the authors is to support the Central HCC Patient Registry, presented at the following website: www.koc.cz.

[Manual and robotic laparoscopic liver resection. Two case-reviews]

INTRODUCTION

Laparoscopic resection of the liver, compared to other laparoscopic procedures of the abdominal cavity, have become used in a clinical practice only in recent years. No literature data on robotic liver resections are available.

METHODS

The authors completed 2 laparoscopic resections of the liver. The first case included a 61-year old male indicated for the procedure with a low differenciated hepatocellular carcinoma lesion in SII and SIII segments, measuring 6 cm in a diameter, in a Child A cirrhotic remodellation terrain. In-line RFA-assisted and HandPort-assisted manual laparoscopic left-sided lobectomy was completed. Histological findings confirmed the diagnosis and the R0 resection. Robotic laparoscopic resection of the focal nodular hyperplasia (FNH) lesion, growing from SII and SIII segments and measuring 7x7x5 cm was completed in the other case of a 29-year old female patient.

RESULTS AND CONCLUSION

Both patients healed without complications, the hospitalization lasted 8 and 7 days, respectively. HandPort-assisted manual laparoscopic resections of the left liver lobe appears a safe method. The patient may benefit from a smaller entrance into the abdominal cavity, compared with open abdominal procedures. Experience in liver and laparoscopic surgery is a prerequisite, which is also supported by literature data. A pilot study must be conducted in order to assess benefits of robotic laparoscopic liver resections.

[Robotic laparoscopic cholecystectomy]

INTRODUCTION

Laparoscopic approach profusely utilized in many surgical fields was enhanced by da Vinci robotic surgical system in range of surgery wards, imprimis in the United States today. There was multispecialized robotic centre program initiated in the Central Military Hospital in Prague in December 2005. Within the scope of implementing the da Vinci robotic system to clinical practice we executed robotic-assisted laparoscopic cholecystectomy.

METHODS

We have accomplished elective laparoscopic cholecystectomy using the da Vinci robotic surgical system. Operating working group (two doctors, two scrub nurses) had completed certificated foreign training. Both of the surgeons have many years experience of laparoscopic cholecystectomy. Operator controlled instruments from the surgeon's console, assistant placed clips on ends of cystic duct and cystic artery from auxiliary port after capnoperitoneum installation. We evacuated gallbladder in plastic bag from abdominal cavity in place of original paraumbilical port. We were exploiting three working arms in all our cases, holding surgical camera, electrocautery hook and Cadiere forceps. We had been observing procedure time, technical complications connected with robotic system, length of hospital stay and complication incidence rate.

RESULTS

We managed to finish all operations in laparoscopic way. Group of our patients formed 11 male patients (35.5%) and 20 women (64.5%), mean aged 52.5 years in range of 27 77 years. The average operation procedure lasted 100 minutes, in the group of last 11 patients only 69 minutes. We recorded paraumbilical wound infections in 3 (9.7 %) patients. We had not experienced any technical problems with robotic surgical system. Length of hospital stay was 3 days.

CONCLUSIONS

Considering our initial experience with robotic lasparoscopic cholecystectomy we evaluate da Vinci robotic surgical system to be safe and sophisticated operating manipulator which however does not substitute the surgeon key-role of controlling position and decision competences. Presented results of our group are comparable to conclusions of abroad published works.

[Atypically localised hepatic haemangioma as a cause of dyspeptic syndrome]

INTRODUCTION

Haemangioma is a benign mesenchymal tumor growing from the endothehum of blood vessels. Most hepatic haemangiomas are asymptomatic while symptomatic haemangioma are usually manifested by non-specific pain dyspeptic syndrome, quite rarely also by hemorrhage, or icterus Symptomatic haemangiomas or large haemangiomas with fast growth, are indicated for surgical treatment.

CASE REPORT

The authors present a 50-year-old patient with chronic dyspeptic condition and pressure pain in the epigastria. USG, CT, MR, CT angiography and EUS have all shown two lesiones (haemangioma of the left hepatic lobe, a tumor in the left subphrenic area of uncertain origin). We proposed an operational solution, and, surprisingly, the finding was a single haemangioma (2 parts-- intra- and extraparenchymatous--connected by a vascular bridge). We then performed left lobectomy.

DISCUSSION

In the diagnosis of haemangioma, MR is a method of choice with high specificity and sensitivity. Why did not it yield the correct diagnosis? The structure, the signal and the type of postcontrast enhancement of the second lesion corresponded to a haemangioma, but the extraparenchymatous location and also the considerable remoteness from the liver invalidated this possibility before operation. Regarding to the differential diagnostics of the lesiones in the subphrenic area, which according to the imaging techniques are not related to the hepatic parenchyma, it is advisable to consider the possibility of the incidence of pedunculated hepatic haemangioma.

1-Hydroxymethylpyrene and its sulfuric acid ester: toxicological effects in vitro and in vivo, and metabolic aspects

1-Hydroxymethylpyrene (HMP) is activated to a potent mutagen, detectable in Salmonella typhimurium, in the presence of hepatic cytosol, cofactor for sulfotransferases, and chloride anions. The number of induced mutations is linear to the amount of cytosol used over a wide range, allowing for the quantification of this activity. The activity is expressed with high selectivity in certain tissues and cell types. In adult rats, the highest level is found in the liver, the activity in females exceeding that in males about threefold. About half of the activity in the liver of females is provided by hydroxysteroid sulfotransferase a (STa), whereas other enzymes may be more important in males on account of their very low level of STa. The expression of STa is decreased in ATPase-negative, presumably preneoplastic, hepatic foci in female rats. In contrast to its high mutagenicity in bacteria, SMP shows only weak mutagenic activity in mammalian cells (Chinese hamster V79 cells), independently of whether it is externally added, or generated from HMP within the cells by heterologously expressed STa. Sulfation, however, strongly enhances the cytotoxicity of HMP in mammalian cells. The high cytotoxicity and low mutagenicity in mammalian cells in culture have possible correlates in vivo: while HMP is only a weak initiator of ATPase-negative hepatic foci in newborn rats, it shows substantial promoting activity with regard to such foci in female, but not in male rats. We postulate that this promotion results from selective toxification by STa in the normal hepatic parenchyma of female rats, and resistance of ATPase/STa-negative foci.

Some substrates and inhibitors of cytosolic epoxide hydrolase induce sister-chromatid exchanges in mammalian cells, but do not induce gene mutations in Salmonella typhimurium and V79 cells

Trans-stilbene oxide, trans-beta-methylstyrene 7,8-oxide, trans-beta-ethylstyrene 7,8-oxide, trans-beta-propylstyrene 7,8-oxide and 4-fluorochalcone oxide were investigated for genotoxic activity in bacterial and mammalian cells, in the absence of external xenobiotic-metabolising systems. All compounds strongly enhanced the frequency of sister-chromatid exchanges (SCE) in cultured human lymphocytes. None of them was mutagenic in Salmonella typhimurium (reversion of the his- strains TA98, TA100 and TA104). The limit of detection was 1/20,000 to 1/10(6) of the activity of the positive control, benzo[a]pyrene 4,5-oxide, depending on the compound and the bacterial strain. Trans-beta-methylstyrene 7,8-oxide and 4-fluorochalcone oxide were additionally tested for induction of SCE and gene mutations in the same target cells, namely Chinese hamster V79 cells. Their influence on the level of SCE was similar to that observed in human lymphocytes, whilst gene mutations (at the hprt locus) were not induced. The four investigated styrene oxide derivatives are known to be excellent substrates for a mammalian enzyme, cytosolic epoxide hydrolase (cEH). 4-Fluorochalcone oxide is a potent selective inhibitor of this enzyme and is structurally similar to the investigated styrene oxide derivatives. These properties of the test compounds however cannot explain the observed discrepancies in the results, since the genetic end point (SCE versus gene mutations) was decisive, and SCE were induced in cEH-proficient human lymphocytes as well as in cEH-deficient V79 cells.