SABCS: Treating CNS Metastases

By Kim Irish, BCA Program Manager

December 8, 2010

The initial day of the 2010 San Antonio Breast Cancer Symposium had a broader focus and was more accessible to advocates.  The conference atmosphere was expectant while BCA staff, board members, and volunteers planned schedules and set up a table full of BCA materials in the exhibit hall.  Topics covered during the educational sessions included advances in neurosurgery related to central nervous system (CNS) metastases and a discussion of the standards for radiation therapy for CNS metastases.  The educational sessions were well-attended and spurred some interesting questions for audience members to consider. 

One fascinating talk given by Elizabeth B. Claus, MD, PhD, of Yale University, was titled “NeuroSurgical Management of CNS Breast Metastases.”  An estimated 20% of breast cancer patients will develop CNS metastases.  Risk factors include young age, ER negative breast tumors, and HER2 positive breast cancer.  Dr. Claus argued in favor of neurosurgery for patients with CNS metastases for several reasons, including relief of symptoms and improvement in quality of life.  She concluded that in the appropriate setting, surgery can be a valuable treatment for CNS metastases, but that breast cancer-specific trials and data are needed for neurosurgery.

The next session was entitled “Radiation Therapy for CNS Metastases: What Should the Standard Be?” given by Minesh P. Mehta, MD, of Northwestern University.  Dr. Mehta is a consultant for a huge array of pharmaceutical companies – Adnexus, Bayer, Merck, Schering, Genentech, and Tomotherapy.  According to Dr. Mehta, key issues in determining the standard for radiation therapy for CNS metastases are the fact that focused therapies like surgery and radiosurgery effectively remove or control one or more intracranial lesions probably better than whole brain radiation therapy (WBRT).  They may also be associated with lower direct cognitive decline, and are associated with higher intracranial failure rates, which might lead to more cognitive decline.  On the other hand, WBRT controls one or more intracranial lesions but probably not as well as surgery or stereotactic radiosurgery (SRS).  WBRT is also associated with higher direct cognitive decline but lower intracranial failure rates.  Dr. Mehta concluded by recommending that surgical resection followed by WBRT is a better treatment option for improving tumor control at the original site of the metastasis and in the brain overall when compared to surgical resection alone.  Finally, SRS alone may provide an equivalent survival advantage for patients with brain metastases compared with SRS combined with WBRT.

From a patient perspective, some important questions were raised during the presentation entitled “Systemic Therapy for CNS Metastases,” by Nancy U. Lin, MD of the Dana-Farber Cancer Institute.  Dr. Lin noted that there are no FDA-approved drugs currently available for systemic treatment of brain metastases.  Her presentation discussed the many unresolved issues related to systemic therapy, including determining the meaningful endpoints and how should they be defined; how much data is required before doing a trial in untreated patients; and what is the appropriate follow up for treated patients.  Dr. Lin concluded with the observation that systemic therapy for CNS disease is an area of increasing research interest, so there may be more data forthcoming.