Surreal image of blood cells floating through a breast cancer ribbon.

Decoding Breast Cancer: How Blood Counts Can Predict Treatment Success

Lena Voss in Health & Wellness August 2025 • 3 min read.

"New research reveals that simple blood tests, focusing on eosinophil levels, could predict how triple-negative and HER2-positive breast cancers respond to neoadjuvant chemotherapy, offering hope for more personalized cancer treatments."

In the ongoing battle against breast cancer, which affects millions globally, researchers are constantly seeking ways to refine treatment strategies. Neoadjuvant chemotherapy, given before surgery, is a common approach, yet predicting its success remains a challenge. Now, a recent study sheds light on the potential of simple blood tests to forecast how well certain breast cancers respond to this treatment.

Published in 'Oncotarget' in 2018, the research explores the role of eosinophils—a type of white blood cell—in predicting the effectiveness of neoadjuvant chemotherapy in patients with triple-negative and hormone receptor-negative/HER2-positive breast cancers. These cancers are known for their aggressive nature and the urgent need for effective, targeted therapies.

The study suggests that by monitoring eosinophil and lymphocyte counts, doctors may gain valuable insights into which patients are most likely to benefit from chemotherapy, potentially paving the way for more personalized and effective cancer care.

Unlocking Clues from Blood Cells: Eosinophils and Lymphocytes

Surreal image of blood cells floating through a breast cancer ribbon.

The study, led by Concetta Elisa Onesti and colleagues, retrospectively analyzed data from 112 breast cancer patients treated with standard neoadjuvant chemotherapy. The focus was on patients with triple-negative breast cancer (TNBC) and hormone receptor-negative/HER2-positive cancer, two subtypes that often require aggressive treatment approaches.

Researchers tracked eosinophil and lymphocyte counts from blood samples taken at baseline and during follow-ups. They then looked for correlations between these counts and key outcomes, including pathological complete response (pCR), relapse rates, and overall survival.

The key findings revealed some promising associations:

Higher eosinophil counts at baseline were linked to a higher rate of pathological complete response.
Elevated eosinophil and lymphocyte counts correlated with improved breast cancer-specific survival rates.
Combining eosinophil and lymphocyte data into a single metric further enhanced the ability to predict treatment response and survival outcomes.

Specifically, patients with a relative eosinophil count of 1.5% or higher showed a significantly better response to chemotherapy. This simple blood test could potentially serve as an early indicator of treatment success, allowing for timely adjustments to therapy if needed. Furthermore, the study introduced the 'eosinophil x lymphocyte product,' a combined measure that proved even more effective in predicting pathological complete response, relapse, and survival rates. This innovative approach underscores the potential of leveraging routine blood tests to refine cancer treatment strategies.

A Promising Horizon for Personalized Cancer Treatment

While these findings offer a promising step toward personalized cancer treatment, the researchers emphasize the need for larger studies to confirm these results and to fully understand the underlying mechanisms. The potential to use simple, affordable blood tests to guide treatment decisions could significantly improve outcomes for patients with aggressive forms of breast cancer, marking a significant stride in the ongoing quest for more effective and personalized cancer care.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.18632/oncotarget.26120, Alternate LINK

Title: Predictive And Prognostic Role Of Peripheral Blood Eosinophil Count In Triple-Negative And Hormone Receptor-Negative/Her2-Positive Breast Cancer Patients Undergoing Neoadjuvant Treatment

Subject: Oncology

Journal: Oncotarget

Publisher: Impact Journals, LLC

Authors: Concetta Elisa Onesti, Claire Josse, Aurélie Poncin, Pierre Frères, Christophe Poulet, Vincent Bours, Guy Jerusalem

Published: 2018-09-14

Everything You Need To Know

How can eosinophil levels in blood tests indicate the effectiveness of chemotherapy for breast cancer?

The research indicates that monitoring eosinophil counts, specifically a relative eosinophil count of 1.5% or higher, in blood samples can serve as an early indicator of treatment success for patients with triple-negative breast cancer and hormone receptor-negative/HER2-positive breast cancer undergoing neoadjuvant chemotherapy. Higher eosinophil counts at baseline were linked to a higher rate of pathological complete response. This allows for potential timely adjustments to therapy if needed.

What is the significance of the 'eosinophil x lymphocyte product' in predicting breast cancer treatment outcomes?

The 'eosinophil x lymphocyte product' is a combined measure derived from routine blood tests that multiplies eosinophil and lymphocyte counts. This metric has proven to be even more effective in predicting pathological complete response, relapse, and survival rates in patients with triple-negative breast cancer and hormone receptor-negative/HER2-positive breast cancer undergoing neoadjuvant chemotherapy. Using this innovative approach refines cancer treatment strategies and improves personalized cancer care.

What does Pathological Complete Response (pCR) mean for breast cancer patients undergoing neoadjuvant chemotherapy?

Pathological Complete Response (pCR) in the context of neoadjuvant chemotherapy refers to the absence of any invasive cancer cells in the breast tissue and sampled lymph nodes at the time of surgery following the completion of chemotherapy. Achieving pCR is a significant indicator of treatment effectiveness and is often associated with improved long-term outcomes, such as reduced relapse rates and increased survival, specifically for patients with triple-negative breast cancer and hormone receptor-negative/HER2-positive breast cancer.

Why is it important to predict the success of neoadjuvant chemotherapy in treating breast cancer?

Neoadjuvant chemotherapy is administered before surgery to shrink the tumor, making it easier to remove and reducing the need for extensive surgery. The ability to predict its success, particularly in aggressive subtypes like triple-negative breast cancer and hormone receptor-negative/HER2-positive breast cancer, is crucial for tailoring treatment plans and improving patient outcomes. If neoadjuvant chemotherapy is not effective, alternative strategies can be explored earlier, potentially preventing unnecessary side effects and disease progression.

Do eosinophil and lymphocyte levels predict treatment response for all types of breast cancer, or are there limitations?

While the 'Oncotarget' study shows that eosinophil and lymphocyte counts predict treatment response in triple-negative breast cancer and hormone receptor-negative/HER2-positive breast cancer, further research is required to determine if these markers are useful for other breast cancer subtypes. Additional studies are needed to validate these findings in larger cohorts and across diverse patient populations. Understanding the underlying biological mechanisms linking eosinophil and lymphocyte levels to treatment response could reveal new therapeutic targets and strategies for personalized cancer care.