pathologic complete response
Also written as: pCR
Complete absence of invasive tumor cells in surgical specimens after preoperative treatment, indicating excellent treatment response.
Full Definition
Pathologic complete response (pCR) is defined as the complete absence of invasive tumor cells in the primary tumor bed and regional lymph nodes following neoadjuvant therapy. This finding on surgical pathology examination indicates an excellent response to preoperative treatment and is associated with improved survival outcomes in many cancer types, particularly breast cancer and rectal cancer. The presence or absence of in situ carcinoma in the definition of pCR varies by cancer type and clinical trial protocols.
Usage
Usage note: Abbreviate as pCR in clinical contexts; distinguish from clinical or radiologic responses.
In Context
- "Surgical pathology confirmed a pathologic complete response to neoadjuvant chemotherapy." — pathology report
- "Achievement of pathologic complete response was associated with improved disease-free survival." — clinical study report