Scope Differences in brain activation patterns Differences observed in chemo-exposed vs. chemo-naive brains at rest Mechanistic Considerations

Overview of Neuroimaging Studies in Evaluating the Post-Chemo Brain International Cognition & Cancer Task Force Conference 15 17 17 March 2012 Dan Silverman, MD, PhD Ahmanson Translational Imaging Division Dept. Molecular and Medical Pharmacology University of California, Los Angeles

Studies of the Post-Chemo Brain Scope Differences in brain activation patterns Differences observed in chemo-exposed vs. chemo-naive brains at rest Mechanistic Considerations Potential Implications for Clinical Decisions

Studies of the Post-Chemo Brain: Scope Imaging studies of regional cerebral function after chemotherapy by structural and functional neuroimaging modalities, with focus upon: * human brain, * data published in peer-reviewed reviewed literature

Inject 15 O-water 2 min scan Baseline control task (read, repeat) PET Scan Protocol Inject 15 O-water 2 min scan 12 min. 12 min. Short-term term memory recall task Inject 15 O-water 2 min scan Long-term memory recall task 12 min. Inject 15 O-water 2 min scan Baseline control task (read, repeat) 12 min. Inject 15 O-water 2 min scan Short-term term memory recall task 12 min. Inject 15 O-water 2 min scan Long-term memory recall task 30 min scan Inject 18 FDG 45 min. uptake Resting metabolism

Cortical Activation in Chemotherapy Treated (left) and Untreated (right) Subjects During Short Term Memory Task Color scale corresponds to voxels with significant activation (p<0.01). Peak activation occurring in the inferior frontal gyrus (bright yellow area in left image), was highly significant (p<0.0005 after correction for multiple comparisons, Z=5.95) in treated patients, but not in untreated patients, who showed more significant activation in the parietal cortex (bright yellow area in right image). See text for details.

fmri published studies Ferguson et al., 2007 Kesler et al., 2009 Cherrier et al. 2010 Cimprich et al., 2010 De Ruiter et al., 2011 Kesler et al., 2011 Scherling et al., 2011 Scherling et al., 2012 Reviewed in ICCTF Neuroimaging Workshop yesterday by Dr. Michiel de Ruiter

Monozygotic Twins Study

Monozygotic Twins Study Twin A: 60 y.o. woman who underwent adjuvant chemo for stage II breast cancer (doxorubicin, docetaxel, cyclophosphamide) 22 months previously, + ongoing tamoxifen Twin B: 60 y.o. woman without cancer from Ferguson et al., J Clin Oncol, 2007

Twin A: More frontal and parietal activation during working memory task by fmri from Ferguson et al., J Clin Oncol, 2007

Monozygotic Twins Study: limitations to keep in mind Structural and functional brain differences between twins were observed, but n n = 1 per group Twins A and B differ in chemo and cancer Twin A still undergoing tamoxifen and cognitive-behavioral therapy from Ferguson et al., J Clin Oncol, 2007

Hypoactivation (fmri) during Memory Encoding of Visual Paired Associates 10 Yrs after High Dose Chemo + Tamoxifen Hypoactivation identified in parahippocampal gyrus (PHG) and posterior parietal cortex (PPC) De Ruiter et al. (2011) Human Brain Mapping

Posterior Hypo activation (fmri) during Memory Encoding of Visual Paired Associates 10 Yrs after High Dose Chemo + Tamoxifen De Ruiter et al. (2011) Vs. Chemo > Control Anterior Hyper activation ([O 15]Water) during Retrieval of Verbal Paired Associates 5 10 Yrs after Standard Dose Chemo Silverman et al. (2007)

Posterior Hypoactivation (fmri) during Memory Encoding of Visual Paired Associates 10 Yrs after High Dose Chemo + Tamoxifen Ruiter et al. (2010) Vs. Chemo > Control Anterior Hyperactivation ([O 15]Water)) during Retrieval of Verbal Paired Associates 5 10 Yrs after Standard Dose Chemo Silverman et al. (2007)

FDG PET Scans in Chemotherapy treated and Untreated Subjects at Rest Chemotherapy No Chemotherapy Breast Ca No Breast Ca 55 y.o. female 55 y.o. female 51 y.o. female Red arrows indicate location of superior frontal gyrus. Yellow arrows indicate location of Broca s area and contralateral counterpart. (ROI analysis was performed by research personnel blinded to subjects therapy and disease status.)

Short term term Visual Memory Test in Which Chemotherapy treated treated Patients Were Impaired: Rey Osterrieth Complex Figure Delayed Recall Visuoconstruction: Subject is required to reproduce this complex figure as accurately as possible. Visual memory: subject must reproduce, uncued, the design from memory.

Correlation of Short Term Recall Performance with Resting Metabolism in Chemotherapy Treated Subjects Sagittal ( left ) and transaxial ( right ) views of statistical parametric maps identifying areas where regional brain metabolism correlated with ROCF performance across chemotherapy-treated subjects. Voxels with correlative significance of p<0.01 are depicted in yellow, and superimposed upon an average MR T1-weighted image for anatomical reference. Red cursor lines intersect at the voxel of peak significance, located in the left inferior frontal cortex.

Lentiform Nucleus Resting Metabolic Activity Decreases in Patients Treated with Chemotherapy + Tamoxifen Averaged l/r LN activity during FDG scan 1.2 1.15 1.1 1.05 1 0.95 * * 0.9 Chemo + Tamoxifen Chemo only Breast Cancer, No Chemo Reference Controls Level of metabolism in lentiform nuclei measured in subjects undergoing chemotherapy+tamoxifen therapy tended to be lower (by 7-8%, p<0.01) than the level seen in all other control groups, including those subjects who received chemotherapy without tamoxifen, as well as those who received no chemotherapy for their breast cancer, and a reference group without chemotherapy or breast cancer. n=31 (11, 5, 5, 10)

Structural MRI published studies Breast Cancer Survivors Saykin et al., 2003 (reduced GM and WM >5yrs) Eberling et al., 2004 Yoshikawa et al., 2005 Inagaki et al., 2007 de Ruiter et al., 2011 Koppelmans et al., 2012 Breast Cancer Prospective McDonald et al., 2010 Reviewed in ICCTF Neuroimaging Workshop yesterday by Dr. Brenna McDonald

Breast Cancer Survivors Saykin et al., 2003 Breast cancer and leukemia survivors treated with chemotherapy and healthy controls (Ns=12 per group) >5 years post-diagnosis, various chemotherapy regimens VBM of gray and white matter Chemotherapy-treated patients showed reduced GM and WM

Gray Matter Density (VBM) Decreases during First Month after Chemotherapy (within group analysis) McDonald et al. (2010) Breast Cancer Res Treat.

Areas of Relatively Decreased Gray Matter Density (VBM) in Subjects with Breast Ca a) Chemo Treated < Healthy Controls at 1 Month b) Non Chemo Chemo Treated < Healthy Controls at 1 Month c) Chemo Treated < Healthy Controls at 1 Year McDonald et al. (2010) Breast Cancer Res Treat.

Demography and Therapy Effects of chemo vs. effects of more advanced cancer stage? ( not specific to this study general problem of non randomization in human studies) McDonald et al. (2010) Breast Cancer Res Treat.

DTI published studies Abraham, 2008 (reduced WM integrity in CC genu) Deprez, 2011 Deruiter, 2011 Deprez, 2012 Reviewed in ICCTF Neuroimaging Workshop yesterday by Dr. Sabine Deprez

Abraham et al. 2008 Adjuvant chemotherapy for breast cancer: effects on cerebral white matter seen in diffusion tensor imaging - Clinical Breast Cancer Methods: FA ROI analysis in genu and splenum of CC Correlation with Processing speed

Deprez et al., 2012 Longitudinal assessment of chemotherapy-induced structural changes in cerebral white matter and its correlation with impaired cognitive functioning. - J Clin Oncol SPM Voxel-based whole brain analysis of FA Correlation FA and neuropsychological tests

Comparing Results Across Modalities and Activation vs. Cognitive Rest Designs

Gray Matter Density (MRI) Decreases vs. Cerebral Blood Flow Increases (PET) Chemo Control Silverman et al. (2007) Breast Cancer Res Treat. McDonald et al. (2010) Breast Cancer Res Treat.

Proposed Candidate Mechanisms from Ahles and Saykin, Nat Rev Cancer, 2007

Candidate Mechanisms: Cytokines chemotherapy agents can boost cytokines some cross the blood-brain barrier some cause release of central cytokines through peripheral-to-central neuronal communication can impair cognitive function direct evidence for role in post-chemo brain remains to be established

Implications for Novel Treatment Options I Etanercept (TNF receptor antagonists) Infliximab (Mab to TNF a) NSAIDS and Thalidomide Cytokine synthesis inhibitors Soluble Cytokine Receptors (competitors) Cytokine Receptor Antagonists Estrogen DHEA Fish Oils (inhibitors of TNF a, IL 1b) Exercise Wilson, Finch, Cohen: Cytokines and Cognition JAGS 50:2041-2056 2002 Illman, Corringham et al: Are Inflammatory Cytokines the Common Link B/T Cancer- Associated Cachexia and Depression? J Suppport Oncol 2005;3:37-50

Implications for Novel Treatment Options II IL 10 (suppresses production of PICs) Being studied in RA, IBD, ARDS, HIV, Psoriasis An MS trial was halted by manufacturer (??) IL 4 (anti allergic, anti inflammatory, anti tumor) Used in Psoriasis, promising in leukemia Negative MS trial (Bayer)

Correlation Between Baseline Cytokine Levels and Baseline FDG Metabolism

Baseline Inflammatory Cytokine Positive Correlations with Regional Brain Metabolism 1 year after Chemo IL1RA CRP IL6 TNF All color voxels are p<0.01.

Baseline CRP Levels Negatively Correlate with Baseline Metabolism of Left Inferior Frontal Gyrus in Chemotherapy Subjects svoi SPM IL1RA negatively correlated with baseline left GFi T=4.08, p<0.0005 Part of Largest Cluster (333 voxels) r=-0.52 p=0.03 All color voxels are p<0.05. At peak voxel in lgfi, p<0.0005. Slice view at 32,20, 2.

Potential Implications of Brain PET Imaging in Clinical Decision-Making Search for baseline brain metabolic indicators of future vulnerability and image-guided guided preventive/therapeutic strategies (e.g. e.g.,, Does a patient having lower inferior frontal metabolism suggest being a potential candidate for cytokine-targeted targeted manipulations?) Monitor cerebral response to potentially neurotoxic therapies -- analogously to using MUGA studies to monitor cardiac response to doxorubicin (Adriamycin) -- taking advantage of the typical lead time (2-10 years) of metabolic changes preceding neurologic symptoms. (This could be accomplished as simple add-on view to whole-body PET studies performed for tumor assessments.)

Candidate Mechanisms Direct chemotherapy toxicity possible Most chemotherapy agents are thought to cross the blood-brain barrier in only low concentrations, however (some exceptions include 5-FU and methotrexate)

J Label Compd Radiopharm 2005; 48: 635-643. 643.

Comparing cyclophosphamide and fluorocyclophosphamide toxic behaviors against breast cancer cells

Small animal PET and CT imaging with [F-18] fluorocyclophosphamide

PET with [F 18]fluorocylophosphamide performed before first course of chemotherapy predicts tumor volume changes measured 3 weeks later. JNM, 2007; 48:2021-2027

Comparing [F 18]fluorocyclophosphamide biodistribution measured by small animal PET and by harvesting organs postmortem

PET versions of the following drugs 18F - Paclitaxe l 5-Fluorouraci l 18F - Cyclophosphamid 18F - Inhibits cellular proliferation through stabilization of tubulin Antimetabolite, analog of pyrimidine, impairs pyrimidine synthesis Alkylating agent, cross-links DNA

Chemotherapy Group (n=20): Baseline Activation during Short Term Memory Tasks

Chemotherapy Group at Baseline: Activation in Inferior Frontal Gyrus during Short-Term Memory Task SPM Largest cluster: Left Inferior Frontal Gyrus (2581 contiguous voxels at p<0.01; peak voxel t = 5.72, p<0.0005) All color voxels are p<0.01. svoi Left Inferior Frontal Gyrus Metabolism (Average SEM) 1,11 1,105 1,1 1,095 1,09 Control STM 0,014 0,012 0,01 0,008 0,006 0,004 0,002 0 STM - Control Region that was most significantly activated during short-term memory task (t=2.90, p=0.01)

Chemotherapy Group at Baseline: Deactivation in Hindbrain during Short-Term Memory Task SPM Most significant cluster: R. ant. Cerebellum/post. Pons t = 7.03, p<0.0005 (p FWE-corr corr=0.001) All color voxels are p<0.01. svoi Pons Metabolism (Average SEM) 0,746 0,744 0,742 0,74 0,738 0,736 0,734 Control STM 0 0,002 0,004 0,006 0,008 0,01 STM - Control Region that was most significantly deactivated during short-term memory task (t=-2.15, p=0.05)

Comparison of Different Cytokine Batches Previous analyses have used batch 1 cytokine values. We have stopped using that batch and now use batches 2 and 3 instead for our analyses. The cytokine values are comparable, so the analysis results should not be substantially affected.