Repeat Biomarker Status in Breast Resection Specimens With Controlled Cold Ischemic Time.

Area of Science:

• Oncology
• Pathology
• Biomarker Analysis

Background:

• Current guidelines recommend a cold ischemic time (CIT) of ≤1 hour for breast specimens to preserve biomarker expression.
• Some studies suggest a CIT of up to 4 hours may be acceptable.

Purpose of the Study:

• To evaluate changes in estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression.
• To assess the impact of optimized cold ischemic time (CIT) on biomarker stability in breast specimens.

Main Methods:

• Retrospective analysis of breast resection specimens with a triage protocol to optimize CIT.
• Assessment of clinicopathologic features and changes in ER, PR, and HER2 expression from biopsy to resection.

Main Results:

• Of 295 excisions with CIT ≤4 hours, 230 (78%) had CIT ≤1 hour and 65 (22%) had CIT >1 hour but ≤4 hours.
• Categorical changes in ER/PR were observed in 17.9% of 56 specimens, and in HER2 in 13.3% of 285 specimens.
• Meaningful changes in HER2 expression occurred in only 1.8% of cases.

Conclusions:

• Optimized cold ischemic time (CIT) infrequently leads to meaningful changes in biomarker expression.
• A CIT of up to 4 hours may be acceptable for breast specimens when appropriately triaged, supporting current guideline flexibility.