National Cancer Institute Clinical Trials: An Overview
How many NCI-supported trials are now in progress?
Which NCI trials does PDQ include?
How many NCI treatment, prevention, and other types of trials are listed in PDQ?
How many NCI trials are listed for the four major types of cancer?
What NCI trials does PDQ not include?
Are there other databases that include NCI trials?
The National Cancer Institute (NCI) spent approximately 800 million dollars in fiscal year 2004 (the latest period for which actual expenditures are available) to fund a vast array of clinical trials designed to test new ways to treat, prevent, detect, or diagnose cancer as well as new methods to improve cancer patients' quality of life. NCI-supported clinical trials take place either intramurally at the National Institutes of Health (NIH) Clinical Center in Bethesda, Maryland, or extramurally at any of the hundreds of academic or private hospitals, cancer centers, or community-based medical practices located in the United States, Puerto Rico, Canada, and Europe that receive NCI funding.
The NCI clinical trials enterprise has grown incrementally over the past several decades. Today, the Institute funnels the majority of its funding dedicated to clinical trials to its extramural partners, which operate at the regional, state, and local levels in order to give the public the widest possible access to clinical studies. The major components of the Institute's extramural clinical research program include
NCI-designated Cancer Centers and Comprehensive Cancer Centers, which are major academic and research institutions characterized by scientific excellence that sustain broad-based, interdisciplinary programs in cancer research;
Specialized Programs of Research Excellence (SPOREs), which bring together basic scientists and clinical researchers to design and implement research programs that can improve cancer prevention, detection, diagnosis, and treatment of specific cancer types, including cancers of the breast, prostate, lung, gastrointestinal system, brain, and skin, as well as lymphoma, genitourinary cancer, head and neck cancer, and ovarian cancer;
Clinical Trials Cooperative Groups, which are networks of research institutions organized according to region or medical specialty that collaborate to conduct large-scale, multisite clinical trials often involving thousands of patients; and
- Community Clinical Oncology Programs, which provide smaller-scale community-based medical facilities and individual physicians with opportunities to participate in clinical trials.
Each of these programs is discussed in greater detail below. Various offices throughout the Institute's major divisions provide administrative support for these programs, which are funded through a variety of mechanisms, including grants that support investigator-initiated basic, translational, or clinical research.
Because NCI's clinical research program is highly decentralized, it can be difficult to capture information that provides a comprehensive overview of the full spectrum of its activities. One of the best publicly accessible sources of up-to-date information about NCI-supported cancer clinical trials is the Physician Data Query (PDQ®) database. The first section of this report is largely based upon information drawn from PDQ and demonstrates how this resource may be used to answer specific questions about NCI-supported trials.
There is no simple answer to this question. NCI supports clinical trials through a variety of funding programs, including grants, contracts, and cooperative agreements, and there is no single listing or database containing all NCI-sponsored trials.
One of the most comprehensive databases of cancer clinical trials is NCI's PDQ database, which is accessible through the NCI Web site, www.cancer.gov. PDQ includes most clinical trials sponsored by NCI. It also includes many cancer trials sponsored by pharmaceutical companies, medical centers, and other groups. PDQ lists both active clinical trials (those currently enrolling patients) and those closed to enrollment but still treating patients and/or collecting data. As of January 2006, PDQ contained approximately 2,932 active cancer clinical trials, of which 1,353 - almost half of the total - were sponsored by NCI.
PDQ includes all intramural trials - those being conducted by NCI researchers at the NIH campus in Bethesda, Maryland. It also contains many extramural trials - those sponsored by NCI and taking place at cancer centers, hospitals, and community-based medical practices around the country and other parts of the world.
Of NCI's extramural trials, PDQ includes all that are conducted through the Clinical Trials Cooperative Groups (networks of researchers and institutions with funding from NCI). PDQ also includes many of the trials funded through other kinds of mechanisms, such as grants and contracts, and trials taking place at NCI-designated Cancer Centers. However, because registration of NCI-supported trials is not required, it is not possible to obtain a complete list of extramural trials through PDQ.
The January 2006 listings in PDQ included 183 active intramural clinical trials. A single figure for the sum total of active extramural trials taking place at any given time cannot be obtained from PDQ. Instead, the database lists categories of clinical trials that have been classified according to their specific scientific review process or funding mechanism(s). In January 2006, categories of extramural trials receiving NCI support included
- 415 Cooperative Group trials,
- 382 NCI-grant-supported trials,
- 29 Specialized Programs of Research Excellence (SPORE) trials, and
- 633 trials initiated by NCI-designated Cancer Centers.
Some clinical trials are funded through more than one administrative mechanism and are therefore included under more than one of the categories listed above. As a result, the sum total of the numbers above for intramural and extramural trials (1,642) exceeds the total number of NCI-sponsored clinical trials in the answer to question 1 (1,353).
As of January 2006, there were
- 1,160 treatment trials,
- 55 prevention trials,
- 58 diagnostic trials,
- 17 screening trials,
- 20 genetics trials, and
- 116 supportive-care trials.
Some clinical trials can be classified as more than one type. For example, a screening trial might also be classified as a genetics trial if it is evaluating a screening method in patients who are genetically predisposed toward developing a particular type of cancer. As a result, the sum total of the numbers above (1,426) exceeds the total number of NCI-sponsored trials in PDQ (1,353) because some trials may be classified as more than one type.
As of January 2006, PDQ listed the following numbers of active NCI-sponsored clinical trials for the four types of cancer with the highest numbers of new cases (incidence) and deaths (mortality) annually:
- 133 for lung cancer (including 95 for non-small cell lung cancer, 33 for small cell lung cancer, and 3 for pulmonary carcinoid tumors),
- 192 for breast cancer (including 152 for female breast cancer and 40 for male breast cancer),
- 90 for prostate cancer, and
- 57 for colon cancer.
Which criteria can be used to search PDQ?
PDQ can be searched on the Internet using either the Basic Search Form or the Advanced Search Form.
The Basic Search Form allows people to search for trials using the criteria of cancer type or stage as well as the trial location (ZIP code proximity or NIH campus, Bethesda, Maryland). (See Help Using the Basic Clinical Trial Search Form for more information.)
With the Advanced Search Form, in addition to cancer type and trial location, people can search on the basis of the phase of the trial (phase I, II, III, or IV), the type of treatment or intervention (for example, chemotherapy or vaccine therapy), the drugs being tested, the sponsoring institution, and other criteria. (See Help Using the Advanced Clinical Trial Search Form.)
People may also request a customized search of PDQ from NCI's Cancer Information Service by calling 1-800-4-CANCER.
Some NCI-sponsored trials may not appear in PDQ because it is not mandatory for investigators to submit their trials to the database. Trials missing from PDQ include some funded through NCI grants or contracts and some taking place at NCI-designated Cancer Centers.
Yes. The NIH, of which NCI is a part, maintains both a registry and a database that include clinical trials:
ClinicalTrials.gov includes all cancer trials listed in PDQ. As of January 2006, the database contained more than 11,450 actively recruiting clinical trials for all disease types - including more than 4,400 for cancer and other neoplasms - sponsored by the NIH, other federal agencies, and the pharmaceutical industry.
The CRISP (Computer Retrieval of Information on Scientific Projects) database lists and describes biomedical research grants and contracts funded by the Department of Health and Human Services, NIH's parent agency. At the end of 2004, this database included about 275 listings for current investigator-initiated (R01) grants for research projects involving the conduct of at least 1 cancer clinical trial.* At that time, CRISP also contained information describing contracts active during the period from 2001 through 2004. These contracts were designed either to support large-scale, multiyear prevention or screening trials or to provide centralized services, such as investigational drug production, for NCI clinical trials. Some, but not all, of the clinical trials in CRISP are also listed in PDQ.
*Note: Many of the clinical trials contained in CRISP are not yet active and, therefore, not yet listed in PDQ.
There are other Web sites that make lists of cancer clinical trials available to the public, including some sites maintained by professional or voluntary groups. Some NCI-designated Cancer Centers maintain lists of their own clinical trials on their Web sites.
Most large cancer clinical trial databases, whether private or publicly accessible, derive information from PDQ.
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