Biomarkers to Guide MBC Treatment Decisions: ESR1, PALB2, TROP2, HRD, ctDNA, and CTCs - Metastatic Breast Cancer Trial Talk

From the Experts

A biomarker is a gene, protein, or molecule produced by the body or tumor in a person with cancer that tells a doctor something about the cancer cells. MBC experts have developed new recommendations for how doctors use biomarker information to carefully make MBC treatment decisions as highlighted in our previous two posts (November 2022; December 2022).

However, some biomarkers require more studies and clinical trials before they can be recommended to guide treatment decisions. These include ESR1 and PALB2 gene mutations, TROP2 protein, homologous recombination deficiency (HRD), and circulating tumor cells (CTCs). Although ctDNA testing is currently not recommended for all people with MBC, ctDNA testing can be used to identify PIK3CA or ESR1 mutations in people with HR+ MBC. People with a PIK3CA mutation may be eligible for alpelisib (Piqray®), and people with an ESR1 mutation may be eligible for elacestrant (OrserduTM).

This month, we continue with the last post in our 3-part series about the biomarkers from these new recommendations that do not have enough information to support their use in treatment decision-making. Clinical trial participation is important to generate and collect information that may lead to new treatment recommendations.

Click the links below to read about emerging research about these biomarkers and clinical trials related to these biomarkers.

Biomarkers for Guiding MBC Treatment
ESR1 Mutations and Oral Selective Estrogen Receptor Degraders (SERDs) and CDK 4/6 Inhibitors
PALB2 Mutations and PARP Inhibitors
HRD and PARP Inhibitors
ctDNA and Circulating Tumor Cells (CTCs)

Last Modified on September 26, 2023



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