About TCGA Data
TCGA collects and analyzes high-quality tumor samples and makes the following data available on the TCGA Data Portal:
- Clinical information about participants in the program
- Metadata about the samples (e.g. the weight of a sample portion, etc.)
- Histopathology slide images from sample portions
- Molecular information derived from the samples (e.g. mRNA/miRNA expression, protein expression, copy number, etc.)
In addition to collecting and analyzing high-quality tumor samples, TCGA is also attempting to include high-quality non-tumor samples in some assays. The goal is to analyze every participant's germline DNA to establish which abnormalities detected in a tumor sample are peculiar to the oncogenic process.
- For most disease studies, TCGA will be able to collect and analyze normal blood samples for the majority of participants with that disease.
- Sometimes a matching normal blood sample is not available. In this case, a normal tissue sample from the same participant may be used as the germline control in DNA assays.
- In the case of RNA assays, normal blood is not a suitable control since the RNA profile of a
blood sample would be expected to differ from the RNA profile of tissue from an organ such as
brain, breast, lung, or ovary regardless of whether that tissue was normal or cancerous.
- For this reason, TCGA attempts to collect some number of normal tissue samples matched to the anatomic site of the tumor but usually not matched to the participant. RNA measurements from these normal samples can be pooled and used to analyze how RNA expression in a tumor differs from RNA expression in normal tissue of the same anatomic origin.
A complete list of cases and associated data is available on the TCGA Data Portal homepage.
- TCGA Program Overview
- User Guides and Help
- TCGA Data Primer: provides a high-level description of TCGA and the data it provides to the research community. The primer is an introduction to TCGA data, data processes, and applications.
- Access Tiers: provides information about Open Access and Controlled Access data