Personalized therapy for breast cancer: A step forward

Credit: Unsplash+

The Research Scope

Researchers at Baylor College of Medicine have made significant progress in personalizing treatment for HER2-positive (HER2+) breast cancer, a variant that accounts for approximately one in every five breast cancer cases.

They’ve developed a method that helps predict how a cancer might respond to a specific, less toxic, treatment.

This work is a major stride towards fulfilling the promise of personalized breast cancer therapy.

HER2-Positive Breast Cancer: An Overview

HER2+ breast cancer is characterized by high levels of HER2 proteins, upon which the cancer relies for rapid growth and metastasis.

Historically, patients suffering from HER2+ breast cancer were only treated with chemotherapy, which yielded poor outcomes.

This scenario improved in the late 1990s when anti-HER2 therapy was introduced, transforming the treatment landscape of this disease.

The Dual Anti-HER2 Drug Strategy

The Baylor team found that targeting the HER2 protein with two anti-HER2 drugs, lapatinib and trastuzumab, prior to surgery resulted in a complete response—where all cancer in the breast disappeared—in approximately 25-30% of cases.

This finding suggested that chemotherapy was not necessary for these patients, thereby sparing them the cost and harmful side-effects of chemo.

Predicting Responses with a Molecular Classifier

The challenge was identifying which patients would fall into the responsive 30% at the time of diagnosis. To address this, the team developed a multiparameter molecular classifier.

This test was designed to predict which patients would respond to anti-HER2 treatment alone, as well as to identify those whose tumors might require additional interventions like chemotherapy.

This molecular classifier comprises three components:

  1. It measures the amount of HER2 gene and protein in the cancer cells and checks whether the expression is homogeneous throughout the tumor.
  2. It analyzes whether the cancer expresses a set of genes that indicate the cancer’s growth dependence on HER2.
  3. It investigates the gene PIK3CA for mutations that could provide alternative molecular routes for cancer cell growth when HER2 protein is blocked.

The Path Forward: Precision Medicine

This development enables a shift towards personalized treatment, tailoring the intervention to the patient’s specific needs, thereby minimizing impact on their quality of life.

The team will now evaluate the molecular classifier in a prospective clinical trial for further validation of its clinical utility.

The research team is optimistic that if validated, this classifier could serve as a molecular triaging tool to safely and appropriately select patients with HER2+ breast cancer for treatment de-escalation.

This discovery is the result of many years of dedicated research and presents a significant stride in personalizing cancer treatment.

If you care about cancer, please read studies about a major cause of deadly breast cancer, and new cancer vaccines could prevent cancer recurrence.

For more information about health, please see recent studies about how drinking milk affects the risks of heart disease and cancer and results showing vitamin D supplements could strongly reduce cancer death.

The study was published in Clinical Cancer Research.

Copyright © 2023 Knowridge Science Report. All rights reserved.