Evaluation of circulating cell-free KRAS mutational status as a molecular monitoring tool in patients with pancreatic cancer

BACKGROUND

Pancreatic carcinoma carries a devastating prognosis and is the 4th leading cause for cancer related death in the US and most European countries. Apart from imaging and CA 19-9, pancreatic carcinoma is still lacking reliable markers to assess tumor dynamics and to monitor treatment response over time. The aim of this study was to evaluate the feasibility of cell free tumor-DNA (cft-DNA), respectively KRAS mutation in peripheral blood, detection as a prognostic and predictive value for chemotherapy monitoring.

METHODS

Serial plasma samples from 42 patients with KRAS mutated pancreatic cancer were prospectively collected and the ctKRAS Mutation Assay (Idylla™, Biocartis, Mechelen, Belgium) of cft-DNA was performed on 29 patients that did not receive curative surgery and went on to palliative chemotherapy. To monitor cft-DNA KRAS mutation levels during treatment quantitative assessment of cft-DNA was performed at baseline and during follow up at predetermined times.

RESULTS

All 29 patients included in our analyses had a detected KRAS mutation in the tumor biopsy. In almost half (48.2%) of patients a KRAS mutation could also be detected in peripheral plasma. Patients with detectable KRAS mutations before treatment start in plasma had a significantly worse survival (16.8 months vs not reached, p < 0.031 and HR 3.303). Looking for a dynamic assessment of tumor response, we found a statistically significant association between the KRAS mutant ratio from first staging CT scan to basal levels with tumor response or progress (p = 0.014).

CONCLUSION

Performing KRAS testing from peripheral blood for patients, who have no elevated tumor markers, might be a novel option for treatment monitoring complementing routine imaging techniques.

Epidemiology and Treatment of Patients with Haemophilia in Austria-Update from the Austrian Haemophilia Registry

The Austrian Haemophilia Registry collects epidemiological data on patients with haemophilia, on treatment modalities and potential side effects. The Registry covers more than 85% of the assumed total number of haemophilia patients in Austria. This report summarizes data on 753 patients: 84.3% (635) have haemophilia A and 15.7% (118) have haemophilia B. Patients' median age is 34 years (range: 1-93 years). Of the total cohort, 39.0% (294) patients have severe haemophilia, 11.3% (85) moderate haemophilia, and 49.4% (372) mild haemophilia. Of the patients with severe haemophilia, 38.4% (113) have been infected with hepatitis C virus (HCV) and 12.6% (37) are human immunodeficiency virus (HIV) positive. Overall, 10.6% (67) of patients with haemophilia A and 1.7% (2) of those with haemophilia B have had an inhibitor in their history. Among patients with severe haemophilia, 68.4% (201) receive prophylaxis and 28.6% (84) receive on-demand therapy. There are 65.0% (191) patients with severe haemophilia who are treated with recombinant products. In conclusion, most patients with severe haemophilia receive prophylactic treatment. HCV and HIV infections are still important issues in the Austrian haemophilia population.

Cytomegalovirus reactivation and its clinical impact in patients with solid tumors

Cytomegalovirus reactivation can be life threatening. However, little evidence on its incidence in solid cancers is available. Therefore our single center Cytomegalovirus polymerase chain reaction database with altogether 890 CMV positive blood serum samples of mainly hematological and oncological patients was retrospectively analyzed to examine the occurrence of Cytomegalovirus reactivation in patients with solid tumors, resulting in 107 patients tested positive for Cytomegalovirus reactivation. Seventeen patients with solid cancer and a positive CMV-PCR test were identified, of which eight patients had clinically relevant CMV disease and received prompt antiviral treatment. Five patients fully recovered, but despite prompt antiviral treatment three patients died. Among these three patients two had significant co-infections (in one case EBV and in the other case Aspergillus) indicating that that CMV reactivation was at least one factor contributing to sepsis. The patient with the EBV co-infection was treated in an adjuvant therapy setting for breast cancer and died due to Cytomegalovirus and Epstein-Barr virus associated pneumonia despite intensive therapy. The other two patients had progressive disease of an underlying pancreatic cancer at the time of CMV diagnosis. One patient died due to attendant uncontrollable Aspergillus pneumonia, the other patient most likely died independent from CMV disease because of massively progressive underlying disease.

Cytomegalovirus reactivation and disease might be underestimated in routine clinical practice. In our retrospective analysis we show that approximately 50 % of our patients suffering from solid cancers with a positive Cytomegalovirus polymerase chain reaction also had clinically relevant Cytomegalovirus disease requiring antiviral therapy.

Abstract P3-11-03: Survival and Patterns of Recurrence Following Conservative Treatment in Triple Negative and Triple Positive Breast Cancers

Breast cancer is a heterogenous disease. The inferior prognosis of the triple-negative phenotype was primarily shown in studies, examining outcome by intrinsic subtype, determined via gene expression profiling. Several population based studies, determining the subtype via immunohistochemistry illustrated an analogous result. However in many of these studies a comparison of the triple-negative cohort with the non-triple negative cohort, including all subtypes of invasive breast cancer, was done. Data comparing the triple negative with the triple positive subgroup are limited. Purpose:

To determine patients characteristics and prognostic significance of triple negative breast cancers in comparison to triple positive breast cancers as defined by immunohistochemistry. Patients and Methods:

A database of 3346 primarily not metastasized, invasive breast cancer patients, diagnosed between 1998 and 2008, in whom all 3 markers (estrogen receptor, progesterone receptor and Her2/neu) were available, was reviewed. 197 patients (5,9 %) had triple negative phenotype, 91 (2,7 %) triple positive phenotype. Patients were treated by surgery (either mastectomy or breast conserving), followed by radiation therapy; a small subset of patients received IORT. Systemic therapy was given according to standard protocols used during the mentioned 10 year interval. Determination of ER and PR status was done by immunohistochemistry. Her2/neu status was obtained using the Hercep Test (DAKO). Hercep Test Scores of 2+ were additionally tested by fluorescent in situ hybridisation (FISH). Results:

Median follow-up time was 47,9 months in the triple negative and 51,4 months in the triple positive cohort. Triple negative breast cancer patients experienced a significantly reduced 3-year total relapse-free survival (82,7 % vs. 93,4 %, p=0,019), 10-year local breast relapse-free survival (92,9 % vs. 97,8 %, p=0,036) and breast-cancer related overall survival (89,7 % vs. 100 %, p=0,002 at 3 years; 85,7% vs. 92,3%, p=0,041 at 10 years). Median survival time to progression and consequently to death was significantly reduced in this cohort (13,9 months vs. 32,1 months, p=0,023 and 8,7 months vs. 39,5 months respectively, p=0,006). In a model adjusted for known prognostic variables triple negative breast cancers were at significantly higher risk for total relapse (HR 4,081, 95 % CI 1,538-10,828, P&lt;0,0001), local relapse (HR 3,139; 95 % CI 0,374-26,325, p=0,031) and death (2,173, 95 % CI 0,612-7,715, p=0,001). The prognostic effect of triple negative breast cancer on 10 year overall survival and 10 year total relaps-free survival was independent of nodal status, grade and the application of systemic therapy.

Conclusions: In comparison with triple positive breast cancer patients those classified as triple negative have a poorer prognosis even under omission of adjuvant trastuzumab treatment (70,3 % of the triple positive patients failed to receive adjuvant trastuzumab in our study)

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-11-03.

Glucose induces anion conductance and cytosol-to-membrane transposition of ICln in INS-1E rat insulinoma cells

The metabolic coupling of insulin secretion by pancreatic beta cells is mediated by membrane depolarization due to increased glucose-driven ATP production and closure of K(ATP) channels. Alternative pathways may involve the activation of anion channels by cell swelling upon glucose uptake. In INS-1E insulinoma cells superfusion with an isotonic solution containing 20 mM glucose or a 30% hypotonic solution leads to the activation of a chloride conductance with biophysical and pharmacological properties of anion currents activated in many other cell types during regulatory volume decrease (RVD), i.e. outward rectification, inactivation at positive membrane potentials and block by anion channel inhibitors like NPPB, DIDS, 4-hydroxytamoxifen and extracellular ATP. The current is not inhibited by tolbutamide and remains activated for at least 10 min when reducing the extracellular glucose concentration from 20 mM to 5 mM, but inactivates back to control levels when cells are exposed to a 20% hypertonic extracellular solution containing 20 mM glucose. This chloride current can likewise be induced by 20 mM 3-Omethylglucose, which is taken up but not metabolized by the cells, suggesting that cellular sugar uptake is involved in current activation. Fluorescence resonance energy transfer (FRET) experiments show that chloride current activation by 20 mM glucose and glucose-induced cell swelling are accompanied by a significant, transient redistribution of the membrane associated fraction of ICln, a multifunctional 'connector hub' protein involved in cell volume regulation and generation of RVD currents.

Hypotonicity and ethanol modulate BK channel activity and chloride currents in GH4/C1 pituitary tumour cells

AIM

Description of the effects of hypotonic cell swelling and ethanol on maxi Ca2+-activated K+ channel (BK channel) activity and Cl- channel activity in GH4/C1 pituitary tumour cells.

METHODS

Whole cell-, cell attached- and outside-out patch clamp measurements, fluorescence (fluo-3) measurements of intracellular Ca2+ concentration, cell size video monitoring.

RESULTS

GH4/C1 pituitary tumour cells respond to both hypotonicity and ethanol with cell swelling which is followed by a regulatory volume decrease (RVD). Tetraethylammonium and 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) induced cell swelling per se and inhibited hypotonicity induced RVD. Ethanol-induced swelling is paralleled by an increase in the intracellular Ca2+ concentration and augmented by DIDS. BK channel activation by hypotonicity and ethanol is demonstrated in patch clamp experiments both in intact cells (cell attached configuration) and a subset of excised membrane patches (outside-out configuration). Cell swelling and addition of ionomycin under isotonic conditions leads to the activation of outwardly rectifying Cl- currents with time dependent activation at positive potentials.

CONCLUSIONS

In GH4/C1 cells both hypotonicity and ethanol lead to cell swelling, RVD and to activation of BK channels. The hypotonicity-induced BK channel activation can also be observed in cell free outside-out patches. Hypotonicity, but not ethanol leads to the activation of Cl- channels with features of Ca2+-activated Cl- currents.