MRI more accurately predicted breast tumor response to neoadjuvant chemotherapy
MRI better predicted a breast tumor’s response to neoadjuvant chemotherapy than clinical assessment, according to study results.
For patients undergoing chemotherapy prior to surgery, changes in size to the primary tumor is positively associated with DFS and OS. Because of this, primary tumor response monitoring has led to an increase in pre-surgical chemotherapy for women with breast cancer, according to researchers.
For the study, Nola M. Hylton, PhD, professor of radiology and biomedical imaging at the University of California in San Francisco and colleagues analyzed data from ACRIN 6657, a large multicenter trial using MRI to measure treatment response in breast cancer.
ACRIN 6657 was opened as a companion trial under the Investigation of Serial Studies to Predict Your Therapeutic Response with Imaging and moLecular Analysis (I-SPY TRIAL) breast cancer trial.
Researchers enrolled 216 female patients between the ages of 26 to 68 years old who were undergoing neoadjuvant chemotherapy for stage II or III breast cancer between May 2002 and March 2006. MRI sessions were performed before, during and after administering chemotherapy. MRI assessment measured tumor diameter, volume and peak signal enhancement ratio.
Results of the study showed MRI was superior to clinical assessment in predicting which patients would have a complete tumor response.
“For prediction of both pathologic complete response (pCR) and residual cancer burden, MRI size measurements were superior to clinical examination at all time points, with tumor volume change showing the greatest relative benefit at the second MRI examination.”
Area under the receiver operating characteristic curve (AUC) estimates for MRI was .75 versus .68 for clinical assessment in predicting pCR. AUC using tumor volume change was superior to clinical examinations at all time points, suggesting volume assessment is a more accurate measurement of breast tumors than clinical approaches, according to Hylton and colleagues.
Hylton and colleagues found that early assessment of treatment response using MRI findings may warrant changes in treatment planning, leading to better clinical outcomes.
“With excellent patient compliance in terms of imaging examinations over the course of this investigation, our study suggests that serial MRI examinations can be used effectively to monitor response to treatment,” Hylton and colleagues wrote.
Disclosure: Dr. Hylton reports no relevant financial disclosures.