What is the significance of an Erythrocyte Sedimentation Rate (ESR) of 1 in breast cancer?

From the Guidelines

An Erythrocyte Sedimentation Rate (ESR) of 1 in breast cancer is not a significant prognostic factor, as ESR is not a relevant biomarker in breast cancer, and the provided evidence focuses on estrogen and progesterone receptor testing, not ESR. The provided evidence discusses the importance of estrogen receptor (ER) testing in breast cancer, with a recommended threshold of ≥ 1% nuclear ER staining by IHC for reporting a positive ER result to predict potential clinical benefit from endocrine therapy treatments 1. The evidence highlights the heterogeneity of low ER-expressing cancers, which may have clinical outcomes and biologic/molecular profiles similar to those of ER-negative cancers, but still may benefit from endocrine therapy 1. Key points to consider in breast cancer management include:

• The role of ER testing in predicting response to endocrine therapy
• The recommended threshold for ER positivity
• The importance of considering the totality of information available about an individual case when making treatment decisions
• The potential benefits and limitations of endocrine therapy in patients with low ER expression The evidence does not support the use of ESR as a prognostic factor in breast cancer, and the focus should be on established biomarkers like ER and progesterone receptor (PgR) to guide treatment decisions.

From the Research

Erythrocyte Sedimentation Rate (ESR) in Breast Cancer

• There is no direct evidence in the provided studies to suggest the significance of an ESR of 1 in breast cancer.
• The studies primarily focus on the role of ESR1 mutations in hormone receptor-positive breast cancer and their impact on treatment outcomes 2, 3, 4, 5, 6.
• ESR1 mutations are identified as a key mechanism of resistance to endocrine therapy, particularly in metastatic hormone receptor-positive breast cancer 3, 4, 5, 6.
• The clinical utility of ESR1 mutations as a biomarker and therapeutic target is an evolving field, with ongoing research into their detection, monitoring, and targeting 5, 6.

Limitations of Current Evidence

• None of the provided studies mention ESR or its significance in breast cancer.
• The studies are focused on the molecular and genetic aspects of breast cancer, specifically ESR1 mutations, and their impact on treatment outcomes 2, 3, 4, 5, 6.