Frequently Asked Questions
- What is TCGA?
- What are TCGA's goals?
- What types of cancer is TCGA studying?
- How do TCGA researchers find key genomic changes in cancer?
- Why is TCGA moving forward now?
- What are the accomplishments so far?
- How will TCGA use the American Recovery and Reinvestment Act funding?
- How will TCGA sustain itself beyond the Recovery Act?
- How can people with cancer support TCGA?
- Where can I find additional information about TCGA?
What is TCGA?
TCGA is a large-scale, collaborative effort by the National Institutes of Health (NIH) to create a comprehensive collection of maps that chart the genomic changes that occur in each type of cancer. This atlas will serve as a valuable resource for researchers around the world, accelerating their efforts to develop new and better ways of fighting cancer.
Administered by the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI), the project involves more than 150 researchers working together at dozens of institutions across the nation.
What are TCGA's goals?
TCGA's goals are to comprehensively map the important genomic changes involved in the major types and subtypes of cancer. TCGA will examine over 11,000 samples across over 20 cancer types. By making all data and analytical tools swiftly available to the research community through public databases, TCGA will accelerate the pace of research aimed at improving cancer diagnosis, treatment and prevention.
What types of cancer is TCGA studying?
Based on the success of a three-year pilot effort that made significant progress in brain (glioblastoma multiforme)and ovarian (serous cystadenocarcinoma) cancers, NIH announced in September 2009 that TCGA will study more than 20 additional types of cancer over the next five years. Cancers are selected for study because of their poor prognosis, overall public health impact, and availability of high-quality tissue samples, among other criteria. TCGA also considers international cancer genome mapping efforts. To learn more about cancers being mapped by TCGA, visit http://cancergenome.nih.gov/cancersselected.
How do TCGA researchers find key genomic changes in cancer?
TCGA researchers identify a cancer's key changes by comparing the genomic material in tumor samples from hundreds of patients with genomic material in healthy tissue samples from the same patients.
This comparison is carried out using high-throughput technologies and methods that look for: small changes in DNA sequence, known as genetic mutations; larger-scale changes in chromosomes, known as copy number variations and chromosomal translocations; changes in gene expression, which are reflected in levels of RNA, a protein-coding molecule produced by genes; and epigenomic changes, which involve patterns of how certain molecules, such as methyl groups, interact with DNA. Researchers also integrate into their analyses clinical information related to patients' treatments and outcomes.
For more details on how the various components of TCGA contribute to comprehensive characterization and analysis efforts, go to:http://cancergenome.nih.gov/abouttcga/programoverview.
Why is TCGA moving forward now?
Several important advances indicate that now is the ideal time for NIH to move forward with TCGA. First, the technologies used to determine the sequence of genomic DNA have undergone a revolutionary change in the last several years. It is now feasible, technically and economically, to consider characterizing entire genomes comprehensively across many hundreds or thousands of cancer samples.
A second advance centers on the increasing evidence that comprehensive knowledge of cancer's genomic changes can lead to more effective diagnosis, treatment and prevention. "Proofs of concept" include the success of new molecularly targeted drugs, such as Gleevec for chronic myeloid leukemia, and the development of genetic tests to identify subsets of cancer patients most likely to respond to chemotherapy drugs, such as Iressa and Tarceva for lung cancer.
A third advance is the availability of the human genome sequence and other genome reference sets. These public databases provide an excellent starting point to compare genomic data derived from various cancers.
Because cancer is a disease caused by genomic changes, TCGA represents the grandest opportunity to apply biomedical research's new found knowledge and technologies to an area of terrible disease and suffering. Consequently, NCI and NHGRI are obligated to tackle more cancers now, a course of action made possible through the investment provided by the American Recovery and Reinvestment Act.
What are the accomplishments so far?
Over the course of a three-year pilot project started in 2006, NCI and NHGRI successfully established the policies, infrastructure, production pipelines, collaborative networks and public databases needed for TCGA's large-scale, systematic approach to identifying genomic changes in cancer.
In a paper published in the journal Nature (455, 1061-1068, 3 October 2008), the pilot's research network reported the first results of its integrated, multi-dimensional analysis of the brain cancer glioblastoma. The landmark study identified three new mutations that occur with significant frequency in glioblastoma and delineated core pathways disrupted in this type of brain cancer. One of the most exciting results was an unexpected observation that points to a potential mechanism of resistance to a common chemotherapy drug used for brain cancer. Read the paper.
By 2009, TCGA had sequenced nearly half of the target cases and second generation sequencing was implemented. Funding allocated through the American Recovery and Reinvestment Act made expansion of TCGA possible. Currently, over 20 cancer types are undergoing complete genomic characterization. See the cancers selected for study.
In a paper published in the journal Nature (474, 609-615, 30 June 2011), TCGA reported their findings of their comprehensive genomic characterization of ovarian cancer. In addition to finding gene expression patterns that may be predictive of survival, the researchers found that the changes in ovarian cancer were quite genomically distinct from cancers previously studied, such as glioblastoma. The researchers believe this suggests that all cancers do not arise from the same sorts of changes, which validates TCGA’s method of studying many cancers. View PubMed Abstract.
How will TCGA use the American Recovery and Reinvestment Act funding?TCGA has received $153.5 million in Recovery Act funding that will enable it to study more than 20 types of cancer.
Specifically, Recovery Act funds will be used to help support the Genome Characterization Centers, to acquire and prepare tissues from cancer patients, to further develop databases and to enhance analytical tools and activities. In addition, DNA sequencing methods and technologies will be expanded to include targeted sequencing of larger numbers of genes and the sequencing of entire cancer genomes.
TCGA's effort will require a significant increase in the number of people in the academic, non-profit and private sectors working collaboratively to generate, analyze and utilize the data. This will lead to the retention and creation of a substantial number of diversified jobs.
Recovery Act funding will also support technological and computational innovations in the area of cancer research, fueling a new generation of scientific discovery. Such an investment will continue to impact the U.S. economy – and research and development – for years to come and will likely have a positive impact on diseases well beyond cancer.
How will TCGA sustain itself beyond the Recovery Act?
NCI and NHGRI regard TCGA as a high-priority program and will continue to support it through regular budget allocations beyond the Recovery Act's two-year funding period. In addition to $18 million per year for data generation and analysis, the NCI will need to provide significant funding for tissues and sample processing to sustain the project. For its part, NHGRI will need to ensure that its NHGRI-funded, large-scale sequencing centers allocate enough capacity to meet TCGA's needs.
How can people with cancer support TCGA?
Samples of healthy and cancerous tissue are essential for TCGA and many other types of cancer research going on across the country. Donating your tissue can be a very important gift to the research process. If you are considering donating your tissue, a good first step would be to ask your doctors whether they are taking part in cancer research or partnering with cancer research groups. Keep in mind that it often is not possible to select the specific research projects in which your sample will be used.
Where can I find additional information about TCGA?
For more information about TCGA, please visit http://cancergenome.nih.gov/.