Publications

Poster pending publication

Title: Neurological and Neuropsychological Impact of Radiation Treatment for Breast Cancer

Area: Clinical psychology

Major Purpose:  Adverse long-term neuropsychological consequences of medical treatment for breast cancer, including chemotherapy and radiation, have been suspected.  Although some studies have reported cognitive deficits in individuals treated with systemic cancer therapies (Anderson-Hanley, Sherman, Riggs, Agocha, & Compas, 2003), relatively few studies have investigated the potential causes of such deficits. 

Procedure:  We examined a group of 61 breast cancer survivors, mean age 59.2 years (SD 8.8), who had received diagnoses of breast cancer 2-23 years prior (mean 5.6 years, SD 4.0).  Study participants completed a battery of neuropsychological tests that assessed intellectual function and memory.  Structural magnetic resonance imaging (MRI) was also conducted with study participants.  Whole brain volumes from MRI scans were obtained using a semi-automated object extraction program that separates the brain from other cranial features such as the skull and eyes.  Quantitative estimates of brain volume were then calculated from these images.

Results:  Univariate analysis of variance showed that breast cancer survivors treated with radiation therapy had significantly smaller whole brain volumes when compared to breast cancer survivors who were not treated with radiation therapy, F(1, 60) = 6.34, p = .015.  This disparity represents a 5.0% difference in brain volume.  A significant difference was not found when brain volumes of breast cancer survivors treated with chemotherapy were compared to volumes of survivors not treated with chemotherapy.  Pearson analyses demonstrated a significant positive correlation (r = .27, p = .038) of whole brain volumes of study participants and their performance scores on the Working Memory Index of the Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler, 1997).  Working memory tasks of the WAIS-III are designed to assess one’s ability to remember and process multiple pieces of information simultaneously. Significant correlations of whole brain volumes and other neuropsychological measures were not present. 

Conclusions:  Study results raise the possibility that radiation treatment for breast cancer, even though it is not directed at the central nervous system, may have adverse neurological consequences.  Changes in brain volume in breast cancer survivors may be related to problems in some domains of cognitive function.  Further study is needed to determine if the findings in this study are directly related to cancer treatment or whether they may be due to other associated factors.

Acknowledgement:  Funding for this study was provided by the Susan G. Komen Breast Cancer Foundation.