SAN ANTONIO – Clinical breast examination (CBE) is superior to MRI for predicting pathologic complete response (pCR) in women with HER2-positive breast cancer, a study presented at the 2016 San Antonio Breast Cancer Symposium (SABCS) has shown.1
“Preoperative identification of pCR is important to decrease surgical morbidity,” said Felipe E. M. Andrade, MD, Hospital Sirio-Libanes, Sao Paulo, Brazil. “Triple negative and overexpressed HER2 tumors can achieve pCR with neoadjuvant chemotherapy in a considerable proportion of patients, but the clinical breast examination and radiologic evaluation of the response to neoadjuvant chemotherapy can have conflicting results.”
Therefore, researchers sought to determine the diagnostic validity of CBE and MRI in predicting pCR after neoadjuvant chemotherapy in women with HER2-positive and triple negative breast cancers.
For the cross-sectional study, investigators analyzed data from 72 patients with breast cancer who were treated with neoadjuvant chemotherapy between 2005 and 2012. Of those, 32 had triple negative tumors and 40 had HER2-positive disease.
Among patients with HER2-positive breast cancer, MRI had a positive predictive value (PPV) of 37.5 (95% CI, 13.7-69.4) and a negative predictive value (NPV) of 81.2 (95% CI, 64.7-91.1) compared with 50.0 (95% CI, 29.0-71.0) and 100.0 (95% CI, 85.1-100.0) for CBE, respectively.
Among those with triple negative tumors, MRI had a PPV of 28.6 (95% CI, 8.2-64.1) and a NPV of 96.0 (95% CI, 80.4-99.3) vs 30.0 (95% CI, 10.8-60.3) and 100.0 (85.1-100.0) for CBE, respectively.
“CBE is superior to MRI in predicting pCR for women with tumors overexpressing HER2,” explained Dr Andrade. “However, CBE and MRI are equivalent in predicting pCR in triple negative tumors.”
The findings ultimately suggest that CBE can be used to monitor tumor response to neoadjuvant chemotherapy, as well as to determine the best approach for surgical management.
1. Andrade FEM, De Barros ACS, Docema MF, et al. Clinical examination and breast MRI as predictors of pathologic complete response post neoadjuvant therapy in HER2 overexpressed subtypes and triple negative breast cancer. Poster presented at: 2016 San Antonio Breast Cancer Symposium; December 6-10, 2016; San Antonio, TX.