Genetic mapping of pancreatic cancer by targeted next-generation sequencing in a cohort of patients managed with nab-paclitaxel-based chemotherapy or agents targeting the EGFR axis: a retrospective analysis of the Hellenic Cooperative Oncology Group (HeCOG).

Pancreatic cancer is one of the most fatal malignancies ranking fourth among the leading causes of cancer death with diagnosis at late stages carrying a dismal prognosis. The aim of our retrospective study was to describe the nature and the incidence of gene mutations and genomic instability in advanced pancreatic adenocarcinomas of a Greek patient population fully annotated with clinicopathological data. We used a targeted next-generation sequencing (NGS) panel encompassing genes commonly mutated in pancreatic tumours in a patient population managed with either nab-paclitaxel regimens or targeted compounds modulating the epidermal growth factor receptor (EGFR)/AKT/mTOR axis. We identified KRAS, TP53, SMAD4 and CDKN2A as being the most prevalent mutations in the study population with the exception of an intriguingly lower incidence regarding KRAS mutants. Homologous recombination gene mutations were found to be mutually exclusive with CDKN2A mutations. The coexistence of both KRAS and TP53 mutation seems to adversely affect the outcome of the patients whether treated with targeted therapy against EGFR/Akt/mTOR axis or cytotoxic drugs. The poor prognosis observed, correlated to late presentation, specific molecular mutations and to high mutational load warrant prospective validating studies and research into the mechanistic pathophysiology of pancreatic tumours for more effective therapeutic targeting.

Cyclin D1 differential activation and its prognostic impact in patients with advanced breast cancer treated with trastuzumab.

INTRODUCTION: We sought to determine the level of activation of the critical components of the cyclin D1-mediated pathway and to evaluate their prognostic significance across the different molecular subtypes of advanced breast cancer. PATIENTS AND METHODS: The study population comprised 219 female patients with advanced breast cancer who had been found to have human epidermal growth factor receptor 2 (HER2)-positive disease by local testing and were all treated with trastuzumab-based regimens. For all tumours, central testing for HER2 was performed, and cyclin D1 gene (CCND1) amplification, mRNA and protein expression were assessed by FISH, quantitative real-time-PCR and immunohistochemistry, respectively. Prognostic impact on clinical endpoints was evaluated with Cox regression analyses. RESULTS: After central testing, only 134 (61.2%) of 219 patients were confirmed to have HER2 gene amplification by FISH and/or 3+ HER2 protein expression by immunohistochemistry. After a median follow-up time of 136.0 months (95% CI 123.3 to 148.9), 105 (78.4%) HER2-positive patients and 76 (89.4%) HER2-negative patients had died, while 80% of the former and 87.1% of the latter had experienced a disease relapse. Patients with positive oestrogen receptor/progesterone receptor status presented with higher cyclin D1 mRNA expression. In the HER2-negative subgroup, patients with negative cyclin D1 protein expression were at higher risk of progression (HR= 1.66, 95%CI 1.01 to 2.72, Wald's p=0.045). Among de novo metastatic patients, the risk of progression was higher for patients with non-amplified CCND1 tumours (HR= 2.00, 95% CI 1.03 to 3.90, p=0.041). CONCLUSION: Aberrant activation of the cyclin D1-mediated pathway appears to reduce the risk of progression in HER2-negative tumours, but not in HER2-positive ones.