Metadata supporting data files in the published article: Retinoblastoma Protein Expression and its Predictors in Triple Negative Breast Cancer

Retinoblastoma protein (Rb) is a product of the RB tumor suppressor gene. Its expression is highly prevalent in luminal breast cancers and is critical to the success of cyclindependent kinase (CDK) 4/6 inhibitor therapy. Clinical trials evaluating CDK 4/6 inhibition in triple-negative breast cancer (TNBC) are currently underway. Retrospective data on the frequency and predictors of Rb expression that may inform rational therapeutic combinations are needed. To address this, the authors of this paper, assessed the frequency of Rb expression by immunohistochemistry (IHC) in a previously reported cohort of primary TNBC, and evaluated clinical and pathologic features predictive of Rb expression.

Data access: The datasets supporting the findings of this study, are not publicly available due to restrictions in the IRB-approved protocol, and to protect research participant privacy. Data will be made available to authorized researchers who have submitted an IRB application. Please contact Dr. Nadine Tung, (email address: ntung@bidmc.harvard.edu) for data access requests.

IRB approval and patient consent: This study was approved by Dana-Farber/ Harvard Cancer Center Institutional Review Board and Scientific Review Committee. Given minimal risk to study patients, no informed consent was required.

Study aims and methodology: The aim of this study was to determine the prevalence and predictors of Rb protein expression in BRCA1-associated and sporadic TNBCs.
A total of 180 TNBC patients (70 BRCA1-associated and 110 sporadic) were involved in the study. The clinical and pathologic features of these cases were previously assessed and reported. For this study, immunohistochemical stains for Rb were performed on tissue microarray sections. Details of treatment and outcome were abstracted from medical records. For more details on the methodology, please read the related published article.

Datasets supporting the tables and supplementary tables in the published article:
Datasets rb_journal.sas7bdat in SAS7BDAT file format, and ARRBOutcomes_DataDictionary_2020-04-15.csv in .csv file format, support tables 1-6 and supplementary tables 1 and 2 of the published article.
The datasets include data on the clinical, pathologic, and molecular features at presentation by retinoblastoma protein status, treatment characteristics by retinoblastoma protein status, recurrence by retinoblastoma protein status, and number of cases of of negative, low positive and positive p53 by molecular features at presentation.

Software needed to access data: The SAS software is required to access the dataset rb_journal.sas7bdat.