May 23, 2012

Breast MRI and Chemo Effectiveness

(Ivanhoe Newswire) — A new study shows that magnetic resonance imaging (MRI), when compared with clinical examination, can actually give an earlier indication of a breast tumor´s response to pre-surgical chemotherapy.

Research shows that women who receive chemotherapy before surgery, known as neoadjuvant chemotherapy, are more likely to achieve breast conservation compared with those receiving chemotherapy after surgery.

Traditionally, clinicians monitor the patient´s response to neoadjuvant chemotherapy with clinical measurements of the size and location of the tumor. However, contrast-enhanced MRI presents itself as a hopeful alternative to this approach by its ability to detect blood vessel formation in tumors, otherwise known as angiogenesis. Angiogenesis is an earlier and more exact marker of tumor response.

The researchers analyzed data from ACRIN 6657, the imaging component of the multicenter Investigation of Serial Studies to Predict Your Therapeutic Response with Imaging and moLecular Analysis (I-SPY TRIAL) breast cancer trial. They compared clinical assessment and MRI in 216 female patients from 26-68 years old who were undergoing neoadjuvant therapy for stage II or III breast cancer. The MRI sessions were conducted before, during, and after administration of a chemotherapy regimen. The imaging results were correlated with subsequent laboratory analysis of surgical samples.

The results revealed that the MRI size measurements were superior to clinical examination at all time points, with the tumor volume change showing the greatest relative benefit at the second MRI exam. MRI surpassed clinical assessment in predicting complete tumor response and residual cancer burden.

This study marks the importance of imaging and how it can play an important role in characterizing tumors and monitoring treatment response in patients.

"What we see on imaging helps us define not just the size of the tumor but its biological activity," Dr. Nola M. Hylton, Ph.D., professor of radiology and biomedical imaging at the University of California in San Francisco, was quoted as saying. "We can observe if the signal increases after contrast injection, and interpret that increase as angiogenic activity. We can also use water diffusion measurements with MRI to provide an indirect reflection of the density of the cells."

Dr. Hylton and colleagues are currently evaluating the I-SPY data to see if MRI can be better for predicting the likelihood of breast cancer recurrence in patients. They are hoping to publish those results later this year.

Source: Radiology, May 2012