Accuracy of clinical examination, digital mammogram, ultrasound, and MRI in determining postneoadjuvant pathologic tumor response in operable breast cancer patients.

BACKGROUND: To determine the accuracy, positive predictive value (PPV), and negative predictive value (NPV) of clinical examination and breast imaging techniques in determining pathologic complete response in patients with locally advanced breast cancer after neoadjuvant therapy.
METHODS: A retrospective review was performed of data collected from patients treated with either neoadjuvant hormonal or chemotherapy between January 2005 and September 2010. Patients were evaluated by one of three surgical breast oncologists before neoadjuvant therapy and within 1 month before surgery by clinical breast examination (CBE), digital mammogram, breast ultrasound, and/or magnetic resonance imaging (MRI). The accuracy, NPV, and PPV of each modality was calculated on the basis of the final pathologic report. Available data from the literature was synthesized.
RESULTS: Sixty-two tumors in 61 patients with a mean age of 56 (range 34-87) years were evaluated. Overall accuracy ranged from 54% (CBE) to 80% (breast ultrasound). All modalities had a PPV greater than 75% for identifying the presence of residual disease. The PPV of each modality was generally higher in the younger patients. The NPV of all methods was less than 50%. The accuracy and NPV were compromised even further in younger patients. The combination of our own data with data available from the literature revealed MRI to be superior with regard to accuracy and PPV, but the NPV of MRIs remained poor at 65%.
CONCLUSIONS: All measured tests are good at predicting the presence of disease on final pathology, but none are able to reliably predict a pathologic complete response.