Original Title: Biomarqueurs tumoraux liés à la prise en charge des personnes atteintes d’un cancer du sein

Authors' objectives: Next-generation sequencing (NGS) is a more recent method that provides gene panelbased analysis of different combinations of target sequences in a variety of genes associated with several pathological conditions, including cancer. With the aim of promoting the judicious use of this type of analysis and to standardize patient care, INESSS has been mandated by the Direction cancérologie (DC) to compile a list of useful biomarkers to guide the management of people with various types of solid tumors, including breast cancer.

Authors' results and conclusions: RESULTS: A total of 53 publications were selected. Biomarkers recommended by expert panels/professional organizations are mostly predictive and include the expression of estrogen receptor, HER2 and PD- L1, various types of alterations in PIK3CA, AKT1, PTEN, ESR1, BRCA1/2, PALB2, HER2, NTRK and RET genes, high microsatellite instability (MSI-H), mismatch repair defects (dMMR) and high tumor mutational load (TMB-H). Progesterone receptors and Ki-67 are two biomarkers identified with a prognostic value only. CONCLUSION: There are several tumor biomarkers associated with the management of individuals with breast cancer. Some are currently used in the context of Quebec practice, while others are associated with drugs that are either not approved or approved for other indications in Canada, or which have been refused listing for the indication under consideration. According to the experts consulted, information provided by biomarker testing would be useful for the management of people with breast cancer, as it contributes to a better characterization of the disease and enables a certain number of patients to benefit from various drug access programs or to be directed towards the appropriate clinical studies. To find clinical trials underway in Quebec, readers are invited to consult the Registre public des essais cliniques du Québec.

Authors' methods: An exhaustive literature review (practice guidelines and expert consensus) was conducted to identify tumor biomarkers recommended for the management of breast cancer or solid tumors targeted by an agnostic therapeutic approach (indirectly including breast cancer). Evidence supporting recommendations from cited organizations was extracted from published primary studies to document the magnitude of benefit derived from the decision to personalize management according to the biomarker detected. Information pertaining to approval and listing status of drugs associated with predictive biomarkers was collected to determine the value of testing for these biomarkers in the current context of Quebec practice.

Project Status: Completed

URL for project: https://www.inesss.qc.ca/publications/repertoire-des-publications/publication/biomarqueurs-tumoraux-lies-a-la-prise-en-charge-des-personnes-atteintes-dune-tumeur-solide.html

Year Published: 2025

URL for published report: https://www.inesss.qc.ca/fileadmin/doc/INESSS/Rapports/Oncologie/Biomarqueur_Cancer_sein_EC_INESSS.pdf

English language abstract: An English language summary is available

Publication Type: Other

Country: Canada

Province: Quebec

Organisation Name: Institut national d'excellence en sante et en services sociaux

Contact Address: L'Institut national d'excellence en sante et en services sociaux (INESSS) , 2021, avenue Union, bureau 10.083, Montreal, Quebec, Canada, H3A 2S9;Tel: 1+514-873-2563, Fax: 1+514-873-1369

Contact Name: demande@inesss.qc.ca

Contact Email: demande@inesss.qc.ca

Copyright: L'Institut national d'excellence en sante et en services sociaux (INESSS)