title: Changes of tumor infiltrating lymphocyte subtypes before and after neoadjuvant endocrine therapy in estrogen receptor-positive breast cancer patients--an immunohistochemical study of Cd8+ and Foxp3+ using double immunostaining with correlation to the pathobiological response of the patients.
abstract: Tumor-stromal interactions involve continuous crosstalk and interactions among different cell types and play pivotal roles in tumorigenesis, tumor development, disease progression, subsequent metastasis, and also tumor response to therapeutic agents. Tumor infiltrating lymphocytes (TILs) are important components of these tumor-stromal interactions. Specific TIL subtypes are known to be involved in the clinical course of individual patients. However, the status of TILs following endocrine therapy has not been studied in breast cancer patients. We evaluated the alterations of TIL subtypes in a cohort of East Asian patients with estrogen receptor-positive breast cancer during the course of neoadjuvant steroidal aromatase inhibitor (AI) therapy, using double immunohistochemical staining of CD8+ and T regulatory cells (Treg) or Foxp3+, yielding the CD8+/Treg ratio in individual patients. Changes in CD8+/Treg ratio before and after therapy were then correlated with pathobiological responses of individual patients based upon alterations of the Ki-67 labeling index (LI). A significant increase in the CD8+/Treg ratio was detected in responders (p=0.028) but not in non-responders, which may reflect the dynamic process in which the host immune response to tumor antigens changed in consequence of an interaction between tumor and stromal cells in its microenvironment following estrogen depletion caused by the AI. The CD8+/Treg ratio in breast cancer tissue can be a potential surrogate marker in surgical pathology specimens for predicting responses to neoadjuvant endocrine therapy, not only incorporating features of carcinoma cells as in Ki-67 LI but also those of adjacent stromal cells in the tumor microenvironment, especially in the early stage of treatment prior to any detectable clinical and/or histopathological changes.
authors.affiliation: Department of Pathology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Monica S M
authors.initials: MS
authors.lastname: Chan
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Saulo J A
authors.initials: SJ
authors.lastname: Felizola
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ueno
authors.forename: Masakazu
authors.initials: M
authors.lastname: Toi
authors.forename: W
authors.initials: W
authors.lastname: Loo
authors.forename: Louis W C
authors.initials: LW
authors.lastname: Chow
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sasano
mesh_terms: D000730:Androstadienes / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000276:immunology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D002986:Clinical Trials as Topic; D005260:Female; D051858:Forkhead Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D016131:Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D016246:Lymphocytes, Tumor-Infiltrating / Q000187:drug effects* / Q000276:immunology* / Q000473:pathology; D020360:Neoadjuvant Therapy; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology / Q000473:pathology
chemical_list: D000730:Androstadienes; D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D014408:Biomarkers, Tumor; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D011960:Receptors, Estrogen; C056516:exemestane