Abstract 2616
Background
The identification of biomarkers to drive treatment is one of the most important objectives of precision medicine. During last years, the role of PIK3CA mutations have been related to clinical benefit deriving from treatment with PI3K, and mTOR inhibitors. In breast cancer (BC), PIK3CA mutations are widely present and the use, in clinical trials, of selective inhibitors improved clinical outcomes. The aim of this study is to assess the value of a monocentric genomic screening program to select patients for trials with experimental targeted agents.
Methods
We examined PIK3CA mutation in a cohort of 312 metastatic BC patients diagnosed at Hospital Clínico València-INCLIVA from Jan-13 to Apr-19. The sequencing of hotspot mutations was performed in primary (29.9%) and metastatic tissue (70.1%). We used two different technologies: MassARRAY technology (Sequenom MassARRAY, OncoCarta v1.0) and Iluminia MiSeq System (customised panel, OncoSpot v.1). Hotspots were selected according to databases already published. To be diagnosed as mutated, tumors needed to harbor at least 5% of mutant alleles. 7 clinical trials against PI3K pathway were available.
Results
PIK3CA analysis was performed in 312 paraffin embedded tumor samples, in which only 5.8% the analysis was not possible due to low quality of DNA. The distribution of BC subtypes were 77.6% Luminal, 13.9% HER2, and 8.5% triple negative (TN). PIK3CA mutations were detected in 96 patients (32.7%). In Luminal, PIK3CA mutations reached 36.8% while only 19.5% in HER2 and 16.0% in TN, respectively. A wide spectrum of PIK3CA mutations was found: H1047R (38.5%), E545K (30.2%), E542K (19.8%), R88Q (3.1%), M1043I (3.1%), N345K (2.1%), P539R (1.0%), K111E (1.0%), C420R (1.0%). One hundred and ninety (64.6%) patients were included in clinical trials, and 74 (38.9%) were treated with PI3K, AKT and mTOR inhibitors.
Conclusions
PIK3CA mutations were widely present among luminal BC, being actually a specific target for new drugs. PIK3CA mutational analysis was easily and successfully performed in our center. The identification of PIK3CA hotspots mutations lead to the access for our patient to novel drugs into clinical trials, achieving relevant clinical benefits in most of the cases.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
A. Lluch: Advisory / Consultancy: Novartis; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Roche/Genentech; Advisory / Consultancy: Eisai; Advisory / Consultancy: Celgene. A. Cervantes: Advisory / Consultancy: Merk serono; Advisory / Consultancy: Roche; Advisory / Consultancy: Beigine; Advisory / Consultancy: Bayer; Advisory / Consultancy: Servier; Advisory / Consultancy: Lilly; Advisory / Consultancy: Novartis; Advisory / Consultancy: Takeda; Advisory / Consultancy: Astelas; Advisory / Consultancy: Pierre Fabre; Speaker Bureau / Expert testimony: Foundation Medicine. All other authors have declared no conflicts of interest.
Resources from the same session
5694 - Findings from a new specialist remote Counselling Service for Neuroendocrine Neoplasm (NEN) patients and family members
Presenter: Catherine Bouvier
Session: Poster Display session 2
Resources:
Abstract
4725 - Hematologic malignancies in temozolomide-treated metastatic pancreatic neuroendocrine tumors
Presenter: Nicole Balmaceda
Session: Poster Display session 2
Resources:
Abstract
5842 - Efficacy and toxicity of combination chemotherapy with cyclophosphamide, vincristine and an anthracycline in patients with metastatic extrapulmonary neuroendocrine carcinoma
Presenter: Leonidas Apostolidis
Session: Poster Display session 2
Resources:
Abstract
1543 - An Australian multi-centre experience of the use of peptide receptor radionuclide therapy for bronchial carcinoid tumours.
Presenter: Lisi Lim
Session: Poster Display session 2
Resources:
Abstract
4175 - Extra-pulmonary (EP) high grade (HG) neuroendocrine carcinoma (NEC): real-life outcomes of fifty-eight patients from a Portuguese cancer center.
Presenter: Rita Conde
Session: Poster Display session 2
Resources:
Abstract
3274 - Efficacy of immune check-point inhibitors (ICPi) in large cell neuroendocrine tumors of lung (LCNET)
Presenter: Shira Sherman
Session: Poster Display session 2
Resources:
Abstract
3534 - HORMONET: Study of Tamoxifen in Well Differentiated Neuroendocrine Tumors and Hormone Receptor Positive Expression
Presenter: Milton Barros
Session: Poster Display session 2
Resources:
Abstract
2137 - Clinical utility of Metabolic Tumor Volume in Papillary Thyroid Carcinoma
Presenter: Norihiko Takemoto
Session: Poster Display session 2
Resources:
Abstract
3864 - Correlation of thyroglobulin (Tg) oscillations with progression-free survival (PFS) in patients with radioactive iodine-refractory (RAI-R) differentiated thyroid carcinoma (DTC) treated with multikinase inhibitors (MKI).
Presenter: Jorge Hernando Cubero
Session: Poster Display session 2
Resources:
Abstract
2820 - Analytical validation of a thyroid cancer diagnostic method based on the relative quantification of CLDN10, HMGA2 and LAMB3 expression
Presenter: Mateus Barrosfilho
Session: Poster Display session 2
Resources:
Abstract