Maria Skondra

Detection of the circulating tumor cells in cancer patients

As the presence of tumor cells circulating in the blood is associated with systemic disease and shortened survival, the establishment of a method to detect circulating tumor cells (CTCs) is of critical importance for a more concise staging and follow-up of cancer patients. Recently, the most robust strategies for the determination of CTCs are the PCR-based methods and the CellSearch® system that exploits the immunofluorescent characterization and isolation of cancer cells. Herein, we analyzed the experimental strategies used for determining CTCs with respect to accuracy, sensitivity and reproducibility in cancers of the breast, colon, prostate and melanoma.

Significance of PIK3CA Mutations in Patients with Early Breast Cancer Treated with Adjuvant Chemotherapy: A Hellenic Cooperative Oncology Group (HeCOG) Study.

Background The PI3K-AKT pathway is frequently activated in breast cancer. PIK3CA mutations are most frequently found in the helical (exon 9) and kinase (exon 20) domains of this protein. The aim of the present study was to examine the role of different types of PIK3CA mutations in combination with molecular biomarkers related to PI3K-AKT signaling in patients with early breast cancer. Methods Tumor tissue samples from 1008 early breast cancer patients treated with adjuvant chemotherapy in two similar randomized trials of HeCOG were examined. Tumors were subtyped with immunohistochemistry (IHC) and FISH for ER, PgR, Ki67, HER2 and androgen receptor (AR). PIK3CA mutations were analyzed by Sanger sequencing (exon 20) and qPCR (exon 9) (Sanger/qPCR mutations). In 610 cases, next generation sequencing (NGS) PIK3CA mutation data were also available. PIK3CA mutations and PTEN protein expression (IHC) were analyzed in luminal tumors (ER and/or PgR positive), molecular apocrine carcinomas (MAC; ER/PgR negative / AR positive) and hormone receptor (ER/PgR/AR) negative tumors. Results PIK3CA mutations were detected in 235/1008 tumors (23%) with Sanger/qPCR and in 149/610 tumors (24%) with NGS. Concordance between the two methods was good with a Kappa coefficient of 0.76 (95% CI 0.69–0.82). Lobular histology, low tumor grade and luminal A tumors were associated with helical domain mutations (PIK3CAhel), while luminal B with kinase domain mutations (PIK3CAkin). The overall incidence of PIK3CA mutations was higher in luminal as compared to MAC and hormone receptor negative tumors (p = 0.004). Disease-free and overall survival did not significantly differ with respect to PIK3CA mutation presence and type. However, a statistically significant interaction between PIK3CA mutation status and PTEN low protein expression with regard to prognosis was identified. Conclusions The present study did not show any prognostic significance of specific PIK3CA mutations in a large group of predominantly lymph-node positive breast cancer women treated with adjuvant chemotherapy. Further analyses in larger cohorts are warranted to investigate possible differential effect of distinct PIK3CA mutations in small subgroups of patients.

Prevalent somatic BRCA1 mutations shape clinically relevant genomic patterns of nasopharyngeal carcinoma in Southeast Europe

Genomic patterns of nasopharyngeal carcinomas (NPCs) have as yet been studied in Southeast Asian (SEA) patients. Here, we investigated genomic patterns of locally advanced NPC Southeast European (SEE) patients treated with chemoradiotherapy. We examined 126 tumors (89% EBV positive) from Greek and Romanian NPC patients with massively parallel sequencing. Paired tumor‐cell‐rich (TC) and infiltrating‐lymphocyte‐rich (TILs) samples were available in 19 and paired tumor‐germline samples in 68 cases. Top mutated genes were BRCA1 (54% of all tumors); BRCA2 (29%); TP53 (22%); KRAS (18%). Based on the presence and number of mutations and mutated genes, NPC were classified as stable (no mutations, n = 27); unstable (>7 genes with multiple mutations, all BRCA1 positive, n = 21); and of intermediate stability (1–7 singly mutated genes, n = 78). BRCA1 p.Q563* was present in 59 tumors (48%), more frequently from Romanian patients (p < 0.001). No pathogenic germline mutations were identified. NPC exhibited APOBEC3A/B and nucleotide‐excision‐repair‐related mutational signatures. As compared to TC, TILs demonstrated few shared and a higher number of low frequency private mutations (p < 0.001). In multivariate analysis models for progression‐free survival, EBV positivity was a favorable prognosticator in stable tumors; BRCA1 mutations were unfavorable only in tumors of intermediate stability. In conclusion, other than described for SEA NPC, somatic BRCA1 mutations were common in SEE NPC; these were shared between TC and TILs, and appeared to affect patient outcome according to tumor genomic stability status. Along with the identified mutational signatures, these novel data may be helpful for designing new treatments for locally advanced NPC.

Evaluation of the Insulin-like Growth Factor Receptor Pathway in Patients with Advanced Breast Cancer Treated with Trastuzumab

Background: Trastuzumab is a monoclonal antibody against HER2-positive breast cancer. Despite improving the natural history of the disease, there is a number of patients who are resistant to it, whereas all patients will eventually develop resistance and disease will progress. Inconsistent preclinical data show that the IGF-R pathway may contribute to either de novo or acquired resistance to trastuzumab. Materials and Methods: In total, 227 trastuzumab-treated metastatic breast cancer patients were evaluated for IGF-1, IGF-1R, GLP-1R, Akt1, Akt2 Akt3 mRNA expression, and IGF-1Rα, IGF-1Rβ, IGF-2R protein expression. Results: Only 139 patients were truly HER2-positive by central assessment. Among HER2-positive patients, high Akt2 and GLP-1R mRNA expression showed a trend towards higher and lower risk of progression, respectively (HR=1.83, 95%CI=0.90-3.72, p=0.094 and HR=0.62, 95%CI=0.36-1.06, p=0.079), while high Akt1 and GLP-1R mRNA expression presented a trend towards unfavorable survival (HR=1.67, 95%CI=0.93-2.99, p=0.086 and HR=1.67, 95%CI=0.94-2.96, p=0.080). Among HER2-negative patients, high GLP-1R mRNA expression and negative stromal IGF-1Rβ protein expression showed a trend towards worse survival (HR=2.31, 95%CI=0.87-6.13, p=0.094 and HR=2.03, 95%CI=0.94-4.35, p=0.071, respectively). In the multivariate analyses, HER2-positive patients with high Akt1 and GLP-1R mRNA expression had a worse survival (HR=1.86, 95%CI=1.01-3.43, p=0.045 and HR=1.83, 95%CI=0.99-3.41, p=0.055, respectively). Conclusion: This study revealed a crosstalk between the IGF-R pathway and HER2. There was evidence that high Akt1 and GLP-1R mRNA expression might affect survival among HER2-positive metastatic breast cancer patients treated with trastuzumab.

Evaluation of the prognostic value of RANK, RANKL, OPG and OPN mRNA expression in high-risk early breast cancer patients treated with anthracycline-containing adjuvant chemotherapy.

e23244Background: Prevention of bone metastases is a major issue for breast cancer patients, as it would improve quality of life in a population where long survival with metastatic disease is antic...

Mo1030 Efficacy of Antiviral Therapy in Reactivation Prophylaxis in Patients With Hepatitis B (HBV) Infection Treated With Different Immunosuppressive Agents

A S L D A b st ra ct s diagnosed with chronic hepatitis B (ICD-9-CM codes 070.2 and 070.3) at our institution during 2011-2014. In addition to patient demographics, characteristics of chronic hepatitis B and treatment patterns were examined. The chi-square test and multivariate logistic model were used in statistical analysis. Results: Our study sample of 111 chronic hepatitis B patients included 66 Asians, 18 African Americans, and 27 other races, with mean age of 46.7 (standard deviation 12.6), 61.3% female, 2.7% with family history of HCC, and 3.6% cirrhotic. Eighteen patients (16.2%) reported at least occasional alcohol use and 49 patients (44.1%) were treated with an anti-HBV medication, mainly tenofovir (n=36) followed by entecavir (n=9). Fifty two patients (46.8%) were deemed at high risk for HCC per the AASLD guideline, of which 51 patients (98.1%) underwent or were recommended to undergo an imaging study (ultrasound, CT or MRI) at their most recent visit. Use of anti-HBV medication was positively associated with age and cirrhosis (both p<0.05) but not family history of HCC, AASLD high-risk status, or other variables. In multivariate logistic regression, age was the only significant predicator of anti-HBV medication use (odds ratio 1.03, 95% confidence interval 1.002 1.07). Conclusions: The majority of chronic hepatitis B patients deemed at high risk for HCC underwent or were recommended to undergo imaging study. Interestingly, such high-risk status for HCC was not associated with a higher likelihood of anti-HBV treatment. Whether recent introduction of generic entecavir will lead to more antiHBV treatment is an important question for future research.

1618PASSESSING THE PRESENCE OF CIRCULATING TUMOR CELLS IN BREAST CANCER PATIENTS USING MULTIPLEX REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION AND SPECIFIC PRIMERS FOR MAMMAGLOBIN, PTHRP AND CK19

ABSTRACT Aim: The aim of this study was to develop a multiplex reverse transcription polymerase chain reaction (RT-PCR) assay for the detection of circulating tumor cells in peripheral blood of patients with breast cancer. Methods: Peripheral blood samples were collected from 54 breast cancer patients and 20 healthy blood donors. Subsequently, the samples processed for RNA extraction and then were analyzed for the expression of PTHrP, CK19 and Mammaglobin using specific primers and multiplex PCR. Results: The detection rates in breast cancer patients for PTHrP, CK19 and Mammaglobin were 68.5%, 63% and 22.2% and for healthy donors 10%, 0% and 10%., respectively. The statistical analysis revealed that PTHrP, CK19 and their combination could be used for diagnosing breast cancer. The combination of positive detection rates of PTHrP with CK19 correlated with the presence of distant metastasis in patients with breast cancer, especially with bone metastasis. Moreover, positive detection rates of CK19 correlated with high proliferation rate of breast cancer Conclusions: Multiplex-PCR based detection of circulating tumor cells can provide useful information for the disease stage and presence of metastasis in breast cancer patients. Disclosure: All authors have declared no conflicts of interest.