Peter Grell

Akt expression and compartmentalization in prediction of clinical outcome in HER2-positive metastatic breast cancer patients treated with trastuzumab.

Trastuzumab is effective in about half of HER2-positive breast cancer patients. The PI3K/Akt signalling pathway plays an important role in the process of primary and secondary resistance to anti-HER2 targeted therapy. We evaluated the relationship between expression, activation and subcellular localization of selected Akt isoforms and response to trastuzumab-based anti-HER2 targeted therapy in patients with HER2-positive metastatic breast cancer. Seventy-four women with verified HER2-positive breast cancer were treated with trastuzumab for metastatic disease. Immunohistochemistry was used to evaluate Akt1, Akt2, pAkt Thr308 and pAkt Ser473 expression. For pAkt, cytoplasmic and nuclear fractions were assessed separately. Even though Akt isoforms were expressed in the majority of tumours, activated Akt (pAkt) was present in the cytoplasm only and not in the nucleus in >20% of tumours, and there was no pAkt at all in another 7–13% of tumours. Patients whose tumours showed strong Akt2 expression and had pAkt (pAkt-Thr308 and/or pAkt-Ser473) detectable in the cytoplasm as well as nucleus (n+c), exhibited improved time to progression (TTP) and overall survival from the initiation of trastuzumab therapy (OSt). Patients with tumours with strong Akt2 and pAkt Thr308 (n+c) had superior TTP (17.0 vs. 7.6 months, P=0.024; HR 0.52) and OSt (51.8 vs. 16.8 months, P=0.0009; HR 0.34) compared to other tumours. Similar results were found for strong Akt2 and pAkt Ser473 (n+c): TTP 13.1 vs. 7.2 months (P=0.085, HR 0.62) and OSt 50.8 vs. 17.0 months (P=0.009; HR 0.45). This study is the first to prove the significance of Akt kinase isoform, activity and compartmentalization for the prediction of response to trastuzumab-based therapy in patients with HER2-positive metastatic breast cancer.

Second cancers in Hodgkin's lymphoma long-term survivals: A 60-year single institutional experience with real-life cohort of 871 patients

Appropriate surveillance guidelines for patients after successful treatment of Hodgkins lymphoma (HL) are needed to reduce mortality of iatrogenic secondary cancers (SC). This large single institutional retrospective study analyses the risk of SC in HL patients treated outside of clinical trials over past decades.

Tumor Expression ofmiR-10b, miR-21, miR-143andmiR-145Is Related to Clinicopathological Features of Gastric Cancer in a Central European Population

Background/Aim: In Western countries, most patients with gastric cancer (GC) present in advanced stages. Therefore, there is imminent clinical need for novel diagnostic and prognostic biomarkers. Deregulation of microRNAs has been reported as a frequent event in GC development in a number of studies. Our study validated the potential of microRNAs to serve as diagnostic and prognostic biomarkers in patients with GC from the Central European population. Materials and Methods: Using quantitative real-time polymerase chain reaction, expression levels of six microRNAs (miR-10b, -21, -93, -107, - 143, and -145) were examined in 67 tumor tissues and 67 paired adjacent gastric tissues, and correlated with clinicopathological features of GC patients. Results: Expression levels of miR-10b, miR-21, miR-93, and miR-107 were significantly higher in GC samples compared to non-tumor tissue. Furthermore, the expression levels of miR-10b, miR-143, and miR-145 positively correlated with advanced stages, and increased expression of miR-10b, miR-21 and miR-145 was significantly associated with worse prognosis of gastric cancer patients. Conclusion: Our results indicate that selected tissue microRNAs have the potential to serve as relevant diagnostic and prognostic biomarkers of GC in a central European population.

Abstract LB-181: The impact of Ras/MAPK/S6K signaling pathway on prediction of clinical outcome in metastatic Her-2 positive breast cancer patients treated with trastuzumab

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: The overexpression of Her-2 (c-erbB2/Neu) in breast cancer is associated with poor prognosis, tumor recurrence and shortened survival. The administration of the trastuzumab significantly improves patients prognosis. However, in spite of these successful results, trastuzumab is effective only in 30-50% of cases. PI3K/Akt and Ras/MAPK signaling pathways are activated through Her-2 receptor and other growth factors’ receptors and both play important role in tumor behavior. Methods: The study included 76 women with verified Her-2+ metastatic breast cancer (MBC) who were treated with trastuzumab based palliative chemotherapy. Immunohistochemistry was performed on formalin fixed, paraffin embedded tissue sections with antibodies against S6K, p-S6K-Ser235/236, MAPK, p-MAPK-Thr202/Tyr204, GSK3β, p-GSK3β-Ser9, mTOR, p-mTOR-Ser2448. The cytoplasmatic and nuclear fractions of the staining were assessed separately. Results: Patients whose tumors showed cytoplasmic (c) and nuclear (n) expression of p- GSK3β-Ser9 exhibited worse PFS compared to tumors with negative p-GSK3β-Ser9 (PFS 5,1 vs 9,1 months; P=0,006). Similar results were also found in p-S6K kinase activity, with the difference that it was possible to observe the dependence on the p-S6K kinase compartmentalization. Patients whose tumors showed p-S6K-Ser235/236 expression accompanied with only cytoplasmatic (c) or nuclear and cytoplasmatic (n+c) staining exhibited worse PFS compared to tumors with negative p-S6K-Ser235/236 expression (negat) (c vs negat: 6,3 vs 16,1 months, P=0,006; n+c vs negat: 7,8 vs 16,1 months, P=0,025). Of the remaining kinases, we showed no effect of their expression on treatment outcome. Conclusions: This study confirms that prediction of the response or resistance to trastuzumab treatment depends on the S6K and GSK3β kinase activity. Patients, whose tumors had high level of p-S6K or p-GSK3β, had poorer benefit from trastuzumab based therapy. These patients are candidates for targeted blockade of PI3K/Akt and/or RAS/MAPK signaling pathways. Supported by the Internal Grant Agency of Ministry of Health, Czech Republic, No.NT/14599 and Biomedreg CZ.1.05/2.1.00/01.0030. Citation Format: Marek Svoboda, Marta Khoylou, Peter Grell, Jiri Navratil, Pavel Fabian, Jaroslav Juracek, Marketa Palacova, Rostislav Vyzula, Marian Hajduch. The impact of Ras/MAPK/S6K signaling pathway on prediction of clinical outcome in metastatic Her-2 positive breast cancer patients treated with trastuzumab. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-181. doi:10.1158/1538-7445.AM2014-LB-181

Factors, Predicting Failure of Adjuvant Hormonotherapy of Breast Carcinoma. A Study in Tamoxifen Treated Patients.

BACKGROUND The latest clinical trials indicate better performance of aromatase inhibitors, compared to tamoxifen, in adjuvant hormonotherapy of breast carcinoma. The identification of molecular markers, predicting resistance to tamoxifen, could help to identify patients, which are most likely to benefit from aromatase inhibitors in up-front adjuvant hormonotherapy. MATERIAL AND METHODS Tissue microarrays were constructed from archival paraffin blocks of primary tumors of 179 patients with estrogen receptor positive operable breast carcinoma in stage I-III, subsequently treated with tamoxifen for five years or until relapse, with at least 7 years follow up available. The amplifications of Her-2 and cyclin D1 genes were evaluated by fluorescence in-situ hybridization. The level of progesterone receptor (PR) and Ki67 were estimated by immunohistochemistry. RESULTS 54 of above patients recurred during follow up. In univariate analysis of disease free survival, the presence of more than three nodal metastases (RR=4,5 p<0,001), grade 3 (RR=2,3 p=0,035), cyclin D1 (RR=3,06 p<0,001) and Her-2 (RR=3,06 p<0,001) amplifications were identified as significant risk factors, together with the negativity of PR (RR=2,1 p=0,013). In multivariate analysis, only clinical stage III (RR=2,6 p=0,003), cyclin D1 (RR=2,7 p=0,001) and Her-2 (RR=2,1 p=0,014) amplifications proved significant. In 77 patients who received adjuvant chemotherapy no statistically significant risk factor was identified. In multivariate analysis of 102 patients without adjuvant chemotherapy only stage III (RR=6,9 p=0,001) and Her-2 amplification (RR=4,5 p=0,001) were confirmed. CONCLUSION The advanced clinical stage, cyclin D1 and Her-2 gene amplifications represent factors, predicting the failure of adjuvant tamoxifen treatment, but their predictive value is much lower in patients receiving adjuvant chemotherapy. This fact indicates, they can reflect the common biological aggressiveness of tumor and need not to be tamoxifen specific.