25min-oct2013

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  • 8/12/2019 25min-Oct2013

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    Towards Patient-Specific Treatment:Medical Applications of Machine Learning

    Russ GreinerAlberta Innovates Centre for Machine Learning

    & Department of Computing Science

    University of Alberta

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    Personalized Medical Treatment Often, many treatment options for a disease

    breast cancer, leukemia, Crohns disease,

    Which is best for Patient#73?

    Dunno.

    Try the first, or

    the one that works on previous patient, or

    latest-&-greatest drug, or

    Better: identify treatment best for specific patient

    Not just Stage 4 melanoma but Stage 4 melanoma, 60yo male, BMI=20,

    + histology + genetics +

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    Approach Requires knowing the connections:

    Patient Features DiseaseX Patient Features Effectiveness of Treatment7

    Unfortunately, NOT known

    Fortunately, there is often data fromprevious patients (with known outcomes)

    LEARN the connections from thathistorical data

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    Supervised Learning Framework:

    Learning a Classifier-catenin -catenin E-cadherin p120 age size pten recur?

    m c n m c n m c n m c n

    4 3 0 2 0 4 0 0 2 2 0 0 60 4 3 Y

    : : : : : : : : : : : : : : : : : :

    0 1 4 3 0 2 0 4 0 0 2 1 2 70 2 4 Y

    1 4 3 0 2 0 4 0 0 2 1 2 0 62 6 1 N

    : : : : : : : : : : : : : : : : : :

    1 2 0 1 4 3 0 2 0 4 0 0 2 71 2 2 N

    -catenin -catenin E-cadherin p120 age size pten

    m c n m c n m c n m c n

    0 1 4 3 0 2 0 4 0 0 2 1 2 70 2 4

    Classifier

    Learner

    recur?

    N

    Novel patient

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    Topics Seeking StudentsApplications

    fMRI [functional Magnetic Resonance Imaging]

    IDM [Intelligent Diabetes Management]

    Cancer Heterogeneity[LDA?]

    Predict Metabolites

    Foundational

    PSSP [Patient Specific Survival Prediction]

    Experimental Design

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    fMRI for

    Psychiatric Disorders

    Many psychiatric disorders look similar

    depression and bipolar disorderoften have similar presentations

    but different treatments

    Variability in population of patients, with same disorder What works for one patient, might not work for another

    Use fMRI (functional Magnetic Resonance Imaging) to distinguish disorders to better identify best treatment

    Our results to date: Intl competition: Distinguish ADHD vs control: best performance, 2 pubs

    Next step: First episode psychosis; Depression vs BiPolar;

    w/ Dept of Psychiatry (M Brown, A Greenshaw, S Dursun, R Ramasubbu,)Skill: Imaging, Signal Processing + MachineLearning (Neurophysiology is useful)

    BOLD

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    Intelligent Diabetes Management Each patient with TypeI diabetes must

    regulate his/her own insulin: Give self a dose of insulin (4x / day), based on

    Current blood glucose level Anticipated carbohydrate consumption Stress

    Dose is based on formula specific to patient varies over time

    Diabetes MD can adjust formulabased on patients Diabetes Diary but only on visits every 3-6 months? none in 3rd word countries

    Automate this policy adaption process Reinforcement Learning! w/ Alberta Diabetes Institute (E Ryan, P Senior, )

    Skill: Reinforcement Learning, Implementation, (Endocrinology is useful)

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    Cancer Heterogeneity Proper treatment depends on specific (sub)disease

    Many diseases are mixtures of subtypes Single patient really has multiple subtypes

    For each individual with BreastCancer Disease = mixture of Strains

    Strain = distn over mutations

    Challenge: Given set of patients, each with set of mutations

    Compute set of (latent) strains,each w/ distn over mutations

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    Topic Modeling

    LDA Specific document

    = mixture of Topics

    Topic= distn over words

    Specific patient= mixture of Strains

    Strain= distn over mutations

    LDA (Latent Dirichlet Allocation)

    Given set of Documents,

    Can learn

    topics, and

    associated distributions Then use this to characterize

    new document

    PatientPatient

    Strains

    Strain

    Strain

    Mutations

    Mutation

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    LDA for Cancer Heterogeneity Colleague in BC Cancer has ~2000

    breast cancer samples including mutations for each

    Learn strain model (using LDA?)

    For new patient:

    Given mutations, predict strain mixture

    Later: consider EVOLUTION of cancersubtypes (within single patient)

    Skill: Graphical models, (Oncology is useful)

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    Predict Metabolites When you eat something

    (food, drink, drug, ):Your body transforms it into products

    metabolized into metabolites

    The body then uses those metabolites

    Food Producers / Drug companies / REALLYwant to understand this process!

    What will DrugX metabolize into??

    No one knows this now But

    We have ~1000 [X, metabolites[X] ] pairs

    Skill: Kernel Methods, (BioChemistry is useful)

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    Topics Seeking StudentsApplications

    fMRI [functional Magnetic Resonance Imaging] IDM [Intelligent Diabetes Management]

    Cancer Heterogeneity [LDA?]

    Predict Metabolites

    Foundational

    PSSP [Patient Specific Survival Prediction]

    Experimental Design

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    Stage 4 Stomach Cancer

    Based on 128 patients

    Median survival time:

    11 months

    80% confidenceinterval

    10% to 90% 2 51 months

    Based ONLY oncancer location/stage

    11 months2 months

    0.9

    0.1

    51 months

    0.5

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    Stomach Stage 4 Cancer

    #1314 #1523

    Cancer Type,

    Stage

    Stomach,

    Stage4

    Stomach,

    Stage4

    Predicted Survival Time 21[6.2 - 76]

    2.2[0.8 4.8]

    Median: 1180% CI: 2- 51

    HGB 143 60

    CREATININE_SERUM 108 305

    ALBUMIN 43 35

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    PSSP Status Survival Prediction Survival Analysis

    Useful for predicting time to death for patient time to relapse for patient time to failure for machine part

    time to re-injury for athlete

    Extends Cox Regression, Kaplan Meier curve,Risk Assess, Involves ALL patient information, Deals effectively with censored data Is well calibrated: statistics mean something!

    Website: http://pssp.srv.ualberta.ca/

    Next steps:* Multiple time probes

    * More robust* High dimensional data*

    Skill: Foundational machine learning,

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    Experimental Design Two standard treatments for Leukemia

    Several tests available + 5 news ones Want a good policy:

    OUR GOAL:

    Part of national project,funded from Terry Fox Research Institute

    Skill: Foundational machine learning,experimental design

    Which tests to run, to best identify

    which patient should get which treatment

    Efficiently find this good policy:training using minimum #patients, #tests

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    Other Tasks Application Pull

    Metabolomic Tasks (small molecule) Brain Tumor Analysis

    Microarray tasks [transplant, cancer, diseases]

    Medical imaging histologically stained slides

    Technology Push

    large p, small n tasks

    Microarray, SNP, MRI (brain tumor), fMRI

    Covariate Shift

    Explaining Gene Signature Anomaly

    you tell me

    30,000 Genes

    3200Enzymes

    2300Chemicals

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    26

    30,000

    SNP Analysis

    Microarray

    Proteomics

    Metabolomics

    SubCell Location

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    Collaborators

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    ResultsGiven Predict

    the subcell location of a BreastCancer

    patients junctional proteins

    her 5 year disease free survival

    a subjects genetics[Single Nucleotide Polymorphisms]

    whether she will develop breastcancer

    the expression level of the genes in awomens breast cancer tumor biopsy

    whether she is ER+ or ER-

    a patients metabolic profile whether s/he will lose muscle mass(cachexia)

    whether s/he should be screenedfor colon cancer

    fMRI scan of subject whether subject has ADHD

    whether subject has psychosis

    MRI scan of brain tumor patient long vs short range survival

    summary of Crohn patients gut flora 1 year relapse, or not

    Pub?

    y

    y

    s

    y

    y

    y

    s

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    Recent Pubs.. all with studentsMultiple Pubs in PLoS One Nucleic Acids Research

    Bioinformatics BMC Bioinformatics Metabolomics Frontiers in Systems Neuroscience

    PLoS Biology Journal of Nutrition Theoretical Biology and Medical

    Modelling Human Genetics Breast Cancer Research & Treatment Current Oncology Radiation Research Clinical Cancer Research Analytic Chemistry Journal of Chromatography B

    as well as Computerized Medical

    Imaging and Graphics

    Medical Image Computingand Computer-AssistedIntervention (MICCAI)

    NIPS ICML

    AAAI

    IJCAI

    UAI EMBC

    ISVC

    See http://tinyurl.com/MedInfo-Papers

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    Topics Seeking Students fMRI [functional Magnetic Resonance Imaging]

    IDM [Intelligent Diabetes Management]

    Cancer Heterogeneity

    Predict Metabolites

    PSSP [Patient Specific Survival Prediction]

    Experimental Design

    Imaging, Signal Processing + MachineLearning (Neurophysiology is useful)

    Foundational machine learning, experimental design

    Graphical Models, (Oncology is useful )

    Reinforcement Learning, Implementation (Endocrinology is useful )

    Foundational machine learning,

    Useful, but NOT necessary

    you can learn what you need!

    Skill: Kernel Methods, (BioChemistry is useful)