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
5489 - Local immune status in cancer cell nests can be a predictor of survival for rectal cancer with neoadjuvant radiotherapy
Presenter: xijin lin
Session: Poster Display session 2
Resources:
Abstract
1653 - Impact of concomitant medications on disease free survival (DFS) and overall survival (OS) in patients from the PETACC8 study.
Presenter: Clémence Brun
Session: Poster Display session 2
Resources:
Abstract
5206 - Updated results of NORDIC 8, a randomised trial of cetuximab every 2 weeks with FOLFIRI or cetuximab with alternating FOLFIRI/FOLFOX in patients with RAS and BRAF wild type metastatic colorectal cancer.
Presenter: Per Pfeiffer
Session: Poster Display session 2
Resources:
Abstract
2992 - Clinical impact of mucinous and poorly differentiated tumors on the outcome of patients with stage II colon cancer: a TOSCA subgroup analysis
Presenter: Gerardo Rosati
Session: Poster Display session 2
Resources:
Abstract
4753 - Exercise improved adjuvant treatment completion rates and treatment-related toxicities in colorectal cancer: A prospective pilot study
Presenter: Hong Jun Kim
Session: Poster Display session 2
Resources:
Abstract
2735 - Bevacizumab plus Oxaliplatin-Based Chemotherapy as Adjuvant Treatment for Colon Cancer (CC): Updated analysis of stage II disease from the AVANT Phase III Randomized trial by the GERCOR Group
Presenter: Aimery De Gramont
Session: Poster Display session 2
Resources:
Abstract
1843 - Multicenter Validation of the Postoperative Carcinoembryonic Antigen Combined Prognostic Model for Stage Ⅲ Colon Cancer
Presenter: Ji Zhu
Session: Poster Display session 2
Resources:
Abstract
2554 - Impact of the IDEA study on clinical practice for stage III colon cancer patients: a French GERCOR - FFCD - GI UNICANCER national survey.
Presenter: Kaissa Ouali
Session: Poster Display session 2
Resources:
Abstract
3285 - Sex hormones and sperm parameters after adjuvant oxaliplatin-based treatment for colorectal cancer
Presenter: Philip Falk
Session: Poster Display session 2
Resources:
Abstract
3905 - Loss of CDX-2 expression is an independent poor prognostic biomarker in colorectal cancer
Presenter: Krittiya Korphaisarn
Session: Poster Display session 2
Resources:
Abstract