pathological complete response
Also written as: pCR — pathological complete response
Absence of invasive cancer cells in surgical specimen following neoadjuvant therapy, indicating optimal treatment response.
Full Definition
Pathological complete response (pCR) is defined as the absence of invasive carcinoma in the primary tumor bed and regional lymph nodes following neoadjuvant therapy, as determined by histopathological examination of the surgical specimen. This finding represents the best possible response to preoperative treatment and is associated with improved long-term survival outcomes in many cancer types. The definition of pCR may vary slightly between cancer types—for example, in breast cancer, residual ductal carcinoma in situ may be present while still qualifying as pCR. Achievement of pCR serves as both a prognostic marker and a surrogate endpoint in clinical trials evaluating neoadjuvant therapies.
Usage
Usage note: Use lowercase 'p' in pCR abbreviation. Spell out fully on first use in formal documents.
In Context
- "Pathological examination revealed complete response with no residual invasive carcinoma." — Pathology report
- "Patients achieving pathological complete response had significantly improved survival rates." — Clinical research paper