Hidden Links: The Complicated Relationship Between Antibiotics, the Microbiome, and Breast Cancer Survival

Dive into Dr. Julia Ransohoff’s recent exploration of the unexpected connection between antibiotics, gut health, and survival rates in triple-negative breast cancer cases. This intriguing study underscores the need for further interdisciplinary research between microbiology and oncology.

5 min

The Complicated Relationship Between Antibiotics, the Microbiome, and Breast Cancer Survival

Exploring the interconnected role of antibiotics, gut health, and breast cancer outcomes.

In an enlightening webinar, Dr. Julia Ransohoff, an MD Fellow in Hematology and Oncology at Stanford, unraveled the intricate relationship between antibiotics, our microbiome, and triple-negative breast cancer survival.
Living amongst a microbial universe, our health outcomes are deeply intertwined with the countless microbes that inhabit our bodies. One growing field of interest in the oncological sphere revolves around understanding the role of these microbes in disease progression and mortality.

Key Takeaways:

  • Triple-negative breast cancer (TNBC) has a significantly lower 5-year survival rate than non-TNBC and accounts for 10 – 20% of all breast cancer diagnoses
  • Antibiotic use in the months preceding a TNBC diagnosis has been linked to worse survival outcomes
  • These studies underline the need for further research to explore the microbiome’s role in cancer treatment and progression


A Deep Dive into TNBC

Triple-negative breast cancer (TNBC) is so-named because its tumor cells do not express estrogen receptors, progesterone receptors, or HER2 proteins that are common in other breast cancers. TNBC makes up 10 – 20% of all breast cancer diagnoses and is a particularly formidable cancer subtype – especially to minoritized and economically disadvantaged patients. With a 5-year overall survival rate that stands at a somber 64% compared to the 81% survival rate for non-TNBC patients, it’s crucial to identify factors that might influence these statistics. One surprising element? The gut microbiome.

Antibiotics and the Microbiome: A Double-Edged Sword for TNBC

While antibiotics are essential tools for combating bacterial infections, their inadvertent effect on our gut microbiota may have broader implications than we once thought. Dr. Ransohoff and her team discovered that patients with TNBC were more likely to have lower lymphocyte counts and worse survival outcomes if they took antibiotics in the months leading up to their diagnosis. These observations inspired a follow-up study to investigate the association between antimicrobial exposure during TNBC treatment and patient survival rates.

The study involved a comprehensive analysis of patient-level data from 772 early-stage TNBC patients that were diagnosed between 2000 and 2014, with a minimum follow-up period of 5 years. Dr. Ransohoff’s analysis found a strong and sustained link between antimicrobial exposure and survival. This association was present for up to three years post-treatment, suggesting that antibiotics may have a prolonged impact on patient outcomes. Interestingly, patients who took antibiotics were also more likely to have a non-normal BMI and lower total lymphocyte or neutrophil counts.

In summary, they found a clear link: increasing antimicrobial exposure during TNBC treatment adversely impacted patient survival. This correlation remained strong even after adjusting for disease severity, suggesting that this impact is directly attributable to antibiotic exposure.

Looking Ahead: The Future of TNBC Treatment

The implications for Dr. Ranshoff’s work go beyond just TNBC treatment. The relationship between the gut microbiome and our overall health, especially in cancer progression, suggests that careful consideration should be given to the number and types of antibiotics prescribed to patients with curable cancers. Further studies are needed to understand this association, including exploring how the gut microbiome shifts during chemotherapy and identifying the relationship between circulating and tumor-associated lymphocytes.

Concluding Thoughts

For those embarking on a career in the biosciences, these revelations underline the immense promises and challenges in the world of biotech. As we continue our quest to unravel the complexities of diseases like TNBC, one thing is clear: interdisciplinary understanding, like the confluence of microbiology and oncology, will pave the way forward.

For those interested in joining the frontlines of these exciting developments, consider these relevant career opportunities at Greatness.bio. Your next big discovery might be just a click away.

The link to the webinar can be found here.

Speaker: Julia Ransohoff, MD

Fellow, Hematology and Oncology Stanford University School of Medicine

Dr. Julia Ransohoff’s research unveils a complex relationship between antibiotics, the microbiome, and triple-negative breast cancer survival. The study shows that antibiotic exposure in the months preceding a TNBC diagnosis is associated with worse patient survival outcomes, meaning that the gut microbiome might have a broader implication in cancer progression and treatment. This study prompts a call for further research and careful consideration in prescribing antibiotics to patients with curable cancers.

Dr. Julia Ransohoff

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