Articles

PIK3CA in breast cancer: a Belgian practical testing guideline

BJMO - volume 15, issue 6, october 2021

G. Broeckx MD, Ir A. Hébrant PhD, N. D’Haene MD, PhD, K. Van de Vijver MD, PhD, J. Van Huysse MD, I. Vanden Bempt MD, PhD, P. Aftimos MD, P. Neven MD, PhD, P. Pauwels MD, PhD

SUMMARY

The PI3K/AKT pathway plays an important role in the oncogenesis of breast cancer. Activating mutations in PI3K, more specifically in the p110α catalytic unit of the class IA PI3K isoform (encoded by the PIK3CA gene), lead to an increased conversion of phosphatidylinositol-4,5-biphosphate (PIP2) to phosphatidylinositol-3,4,5-triphosphate (PIP3) inducing a cell signalling cascade for cell proliferation and cell survival. PIK3CA mutations are found in 20–32% of all breast cancers (BC), particularly in hormone sensitive (HR+) BC. In breast cancer, activation of the PI3K pathway coexists with the activation of the oestrogen receptor pathway. Inhibition of one of these pathways may lead to compensatory activation of the other pathway. Therefore, mono-therapy with PI3K inhibitors has limited activity in HR+ BC. On the other hand, this explains the efficacy of a PI3K/ER dual blockade. This dual blockade is researched in the phase III SOLAR-1 trial. In the PIK3CA-mutated cohort of this study, there is an improved outcome for patients with advanced or metastatic HR+ HER2- BC, harbouring activating hotspot mutations in PIK3CA and previously treated with an aromatase inhibitor and no more than one line of endocrine therapy for MBC, who received fulvestrant (a selective oestrogen receptor degrader) and alpelisib (a p110α-isoform specific inhibitor) in comparison to the patients that received fulvestrant and placebo. Based on these results, a medical need program for alpelisib in a heavily pre-treated setting and an amendment were approved by the EMA and the Belgian FAMHP. Supporting this data, we propose the mutational analysis of PIK3CA, preferably by next generation sequencing on FFPE tumour material, in advanced or metastatic HR+ HER2- BC, previously treated with three lines of systemic therapy.

(BELG J MED ONCOL 2021;15(6):304-14)

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Molecular test algorithms for breast tumours

BJMO - volume 13, issue 2, march 2019

Ir A. Hébrant PhD, K. Punie MD, F.P. Duhoux MD, PhD, C. Colpaert MD, PhD, G. Floris MD, PhD, K. Lambein MD, PhD, P. Neven MD, PhD, M. Berlière MD, PhD, R. Salgado MD, PhD, M. Chintinne MD, PhD, K. Dahan MD, PhD, S. Dedeurwaerdere MD, J. De Grève MD, PhD, A. de Leener MD, PhD, H. Denys MD, PhD, R. de Putter MD, L. Desmyter PhD, M. Baldewijns MD, PhD, D. Feret MD, C. Fontaine MD, C. Galant MD, P. Hilbert PhD, J. Janssens MD, PhD, D. Larsimont MD, PhD, P. Lefesvre MD, PhD, T. Sticca PhD, M-D. Tkint de Roodenbeke MD, G. Van Den Eynden MD, PhD, I. Vanden Bempt MD, PhD, C. Van den Broecke MD, I. Vandernoot MD, C. Sotiriou MD, PhD, J. van Dorpe MD, PhD, H.A. Poirel MD, PhD, E. Van Valckenborgh PhD, G. Raicevic PhD, M. Van den Bulcke PhD, P. Aftimos MD

SUMMARY

In order to advise the Federal Government on all matters related to personalised medicine in oncology, including the reimbursement of molecular tests, the Commission of Personalized Medicine (ComPerMed) has applied, for the breast tumours, the same methodology as previously applied for the digestive tumours. Meaning, the different molecular tests, represented in the shape of algorithms, are annotated with test levels — which aim to reflect their relevance based on current available data and to define the reimbursement — and are documented with recent literature, guidelines and a brief technical description.

(BELG J MED ONCOL 2019;13(2):40–45)

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Precision medicine in breast cancer: current practice and perspectives

BJMO - volume 12, issue 3, february 2018

P. Aftimos MD

Just to set the scene: precision, or personalized medicine, is an approach to patient care that allows physicians to select treatments that are most likely to help their patients based on a genomic characterization of the disease, the environment and the way of life of the patient.

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The Belgian next generation sequencing guidelines for haematological and solid tumours

BJMO - volume 11, issue 2, march 2017

Ir A. Hébrant PhD, G. Froyen PhD, B. Maes MD, PhD, R. Salgado MD, PhD, M. Le Mercier PhD, N. D’Haene MD, PhD, S. De Keersmaecker PhD, K. Claes PhD, J. Van der Meulen MD, P. Aftimos MD, J. Van Houdt PhD, K. Cuppens MD, K. Vanneste PhD, E. Dequeker PhD, S. Van Dooren PhD, J. Van Huysse MD, F. Nollet PhD, S. Van Laere PhD, B. Denys MD, V. Ghislain , C. Van Campenhout PhD, M. Van den Bulcke PhD

SUMMARY

Targeted next generation sequencing is a complex procedure including the ‘wet bench’ and ‘dry bench’ parts. Both parts are composed of many steps for which optimal assay conditions and settings must be determined.

The aim of these guidelines is to provide generic, platform independent, recommendations for targeted next generation sequencing tests to detect acquired somatic mutations in DNA, in (haemato)-oncology that are complementary to the ISO 15189 norm (medical laboratories) in order to:

  1. facilitate the implementation of the required quality metrics for the detection of somatic variants by next generation sequencing in oncology and haemato-oncology in the Belgian laboratories,
  2. harmonise test validation and verification,
  3. harmonise clinical interpretation and reporting of variants and,
  4. assure and maintain optimal test performance by establishing procedures and modalities for internal quality control and external quality assessments.

(BELG J MED ONCOL 2017;11(2):56–67)

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