Understanding the relationship between chemotherapy and cognitive impairment requires information on pre-treatment variability between cancer patients and well-matched controls. The purpose of this study was to investigate neuroanatomical differences between breast cancer (BC) patients and controls, prior to chemotherapy,controllingfor possible confounding variables. Twenty-three female early-stage BC patients underwent MRI scanning after surgery but before chemotherapy and were sex-, age-and education-matched to non-cancer controls. Whole brain and region of interest (ROI) group comparisons of grey (GM) and white matter (WM) were performed using voxel-based morphometry.Significant ROI structural differences between BC patients and controls were found depending on the type of analysis used and the covariates entered. This is one of the first imaging studies to focus on pre-chemotherapy neuroanatomical differences between BC patients and well-matched controls, considering demographic, psychological and biological factors in the analyses. Results highlight the importance of better understanding the whole patient prior to chemotherapy, stressing the importance of rigorous methodological procedures.
Keywords:Cognitive impairment, Magnetic resonance imaging (MRI), Voxel-based morphometry (VBM), Pre-treatment effects, Chemotherapy, Surgery, Neuropsychology, Anatomy
IntroductionRecent medical advances have greatly improved the odds of achieving long term survival in cancer patients. This has led to increased attention for improving post-treatment quality of life. One factor of particular interest is related to patient self-reports of cognitive impairments following chemotherapy treatment, most often revealed in breast cancer (BC) populations. Patients have coined terms like "chemo fog" and "chemo brain" to refer to these changes that can manifest both during and after treatment. The incidence of chemotherapy-related impairments is www.ccsenet.org/ijb International Journal of Biology Vol. 4, No. 2; April 2012 ISSN 1916-9671 E-ISSN 1916 4 highly variable with a range of 17-75% reported across neuropsychological studies (Correa & Ahles, 1997). Despite this variability, these assessments, along with both structural and functional neuroimaging investigations, support the existence of the self-reported deficits (Abraham et al., 2008; Ahles et al., 2002; Ahles, Tope, Furstenberg, Hann, & Mills, 1996; Bender et al., 2006; Berglund, Bolund, Fornander, Rutqvist, & Sjoden,1991; Brezden, Phillips, Bunston, & Tannock, 2000; Brown et al., 1998;Castellon et al., 2004; Deprezet al., 2003; de Ruiter et al., 2010; Ferguson, McDonald, Saykin, & Ahles, 2007; Gottschalk, Holcombe, Jackson, & Bechtel, 2003; Hurria et al., 2006; Inagaki et al., 2007; Jenkins et al., 2006; Kesler et al., 2009;Kreukels et al., 2005;Kreukels et al., 2006; Kreukels et al., 2008;Mar Fan et al., 2005;McDonald, Conroy, Ahles, West, & Saykin, 2010;Saykin et al., 2006;Saykin, Ahles, & Schoenfeld, 2003; Schagen et al., 1999;Scherwath et al., 2006; Serva...