title: Computational pathology of pre-treatment biopsies identifies lymphocyte density as a predictor of response to neoadjuvant chemotherapy in breast cancer.
abstract: BACKGROUND
  There is a need to improve prediction of response to chemotherapy in breast cancer in order to improve clinical management and this may be achieved by harnessing computational metrics of tissue pathology. We investigated the association between quantitative image metrics derived from computational analysis of digital pathology slides and response to chemotherapy in women with breast cancer who received neoadjuvant chemotherapy.
  
  
  METHODS
  We digitised tissue sections of both diagnostic and surgical samples of breast tumours from 768 patients enrolled in the Neo-tAnGo randomized controlled trial. We subjected digital images to systematic analysis optimised for detection of single cells. Machine-learning methods were used to classify cells as cancer, stromal or lymphocyte and we computed estimates of absolute numbers, relative fractions and cell densities using these data. Pathological complete response (pCR), a histological indicator of chemotherapy response, was the primary endpoint. Fifteen image metrics were tested for their association with pCR using univariate and multivariate logistic regression.
  
  
  RESULTS
  Median lymphocyte density proved most strongly associated with pCR on univariate analysis (OR 4.46, 95 % CI 2.34-8.50, p < 0.0001; observations = 614) and on multivariate analysis (OR 2.42, 95 % CI 1.08-5.40, p = 0.03; observations = 406) after adjustment for clinical factors. Further exploratory analyses revealed that in approximately one quarter of cases there was an increase in lymphocyte density in the tumour removed at surgery compared to diagnostic biopsies. A reduction in lymphocyte density at surgery was strongly associated with pCR (OR 0.28, 95 % CI 0.17-0.47, p < 0.0001; observations = 553).
  
  
  CONCLUSIONS
  A data-driven analysis of computational pathology reveals lymphocyte density as an independent predictor of pCR. Paradoxically an increase in lymphocyte density, following exposure to chemotherapy, is associated with a lack of pCR. Computational pathology can provide objective, quantitative and reproducible tissue metrics and represents a viable means of outcome prediction in breast cancer.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00070278 ; 03/10/2003.
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK. raza.ali@cruk.cam.ac.uk.|Department of Pathology, University of Cambridge, Cambridge, UK. raza.ali@cruk.cam.ac.uk.
authors.forename: H Raza
authors.initials: HR
authors.lastname: Ali
authors.affiliation: Institute of Astronomy, University of Cambridge, Cambridge, UK. adariush@ast.cam.ac.uk.
authors.forename: Aliakbar
authors.initials: A
authors.lastname: Dariush
authors.affiliation: Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. elena.provenzano@addenbrookes.nhs.uk.|Department of Histopathology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK. elena.provenzano@addenbrookes.nhs.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. elena.provenzano@addenbrookes.nhs.uk.
authors.forename: Elena
authors.initials: E
authors.lastname: Provenzano
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK. helen.bardwell@cruk.cam.ac.uk.
authors.forename: Helen
authors.initials: H
authors.lastname: Bardwell
authors.affiliation: Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. ja344@medschl.cam.ac.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. ja344@medschl.cam.ac.uk.
authors.forename: Jean E
authors.initials: JE
authors.lastname: Abraham
authors.affiliation: Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. mahesh.iddawela@monash.edu.|Present address: Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia. mahesh.iddawela@monash.edu.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Iddawela
authors.affiliation: Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. Anne-Laure.Vallier@addenbrookes.nhs.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. Anne-Laure.Vallier@addenbrookes.nhs.uk.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Vallier
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK. l.hiller@warwick.ac.uk.
authors.forename: Louise
authors.initials: L
authors.lastname: Hiller
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK. J.A.Dunn@warwick.ac.uk.
authors.forename: Janet A
authors.initials: JA
authors.lastname: Dunn
authors.affiliation: Cancer Research UK Clinical Trials Unit, Institute for Cancer Studies, The University of Birmingham, Edgbaston, Birmingham, UK. s.j.bowden@bham.ac.uk.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Bowden
authors.affiliation: Royal Bournemouth Hospital and Bournemouth University, Castle Lane East, Bournemouth, UK. tamas.hickish@rbch.nhs.uk.
authors.forename: Tamas
authors.initials: T
authors.lastname: Hickish
authors.affiliation: Peterborough and Stamford Hospitals NHS Foundation Trust and Cambridge University Hospital NHS Foundation Trust, Peterborough, UK. karen.mcadam@pbh-tr.nhs.uk.
authors.forename: Karen
authors.initials: K
authors.lastname: McAdam
authors.affiliation: Royal Surrey County Hospital NHS Foundation Trust, Egerton Road, Guildford, UK. shouston@nhs.net.
authors.forename: Stephen
authors.initials: S
authors.lastname: Houston
authors.affiliation: Institute of Astronomy, University of Cambridge, Cambridge, UK. mike@ast.cam.ac.uk.
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Irwin
authors.affiliation: Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. pp10001@medschl.cam.ac.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. pp10001@medschl.cam.ac.uk.
authors.forename: Paul D P
authors.initials: PD
authors.lastname: Pharoah
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK. james.brenton@cruk.cam.ac.uk.|Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. james.brenton@cruk.cam.ac.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. james.brenton@cruk.cam.ac.uk.
authors.forename: James D
authors.initials: JD
authors.lastname: Brenton
authors.affiliation: Institute of Astronomy, University of Cambridge, Cambridge, UK. naw@ast.cam.ac.uk.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Walton
authors.affiliation: Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. hme22@cam.ac.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. hme22@cam.ac.uk.
authors.forename: Helena M
authors.initials: HM
authors.lastname: Earl
authors.affiliation: Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, UK. carlos.caldas@cruk.cam.ac.uk.|Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. carlos.caldas@cruk.cam.ac.uk.|Cambridge Experimental Cancer Medicine Centre and NIHR Cambridge Biomedical Research Centre, Cambridge, UK. carlos.caldas@cruk.cam.ac.uk.
authors.forename: Carlos
authors.initials: C
authors.lastname: Caldas
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000097:blood; D001706:Biopsy; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000473:pathology*; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics; D043823:Taxoids / Q000008:administration & dosage
chemical_list: D014408:Biomarkers, Tumor; D015251:Epirubicin; D018719:Erb-b2 Receptor Tyrosine Kinases; D043823:Taxoids