In an encouraging sign for both oncologists and patients, the number of open clinical trials listed in U.S. and international clinical trial registries is on the rise. This trend reflects several factors, including an effort by the editors of the world's leading medical journals to broaden the registries' offerings.

Giving physicians and patients a more complete picture of the trials that are currently open to patient enrollment potentially increases the available treatment options they can consider. Because some registries also include information about closed trials, increasing the completeness of those registries makes them more valuable to researchers who may be planning future trials or want to know more about trials that have been conducted in the past.

The availability of a publicly accessible, comprehensive clinical trial registry is a relatively recent event. NCI's Physician Data Query (PDQ®) clinical trial registry, which was started in 1977, is perhaps the world's oldest continuously operating registry, but PDQ focuses only on cancer trials and registration in PDQ is largely voluntary.

Trial registration became more comprehensive and compulsory with the passage of the 1997 FDA Modernization Act (FDAMA). FDAMA requires the registration of all phase II or higher trials conducted under an FDA Investigational New Drug application in which the efficacy of a treatment for a serious or life-threatening condition is being tested. FDAMA also led to the creation of ClinicalTrials.gov (http://clinicaltrials.gov) as the central clinical trial registry for the United States. ClinicalTrials.gov is managed by the U.S. National Library of Medicine at NIH.

Analyses conducted by FDA in 2002 and 2004 revealed that compliance with FDAMA's trial registration requirements was less than complete. For example, during the 3-month period from May through July 2004, FDA found that NIH had registered 95 percent of the required trials it funds in ClinicalTrials.gov. In contrast, only 66 percent of the required trials sponsored by the pharmaceutical industry had been registered.

In 2004, the International Committee of Medical Journal Editors issued a directive: Beginning on July 1, 2005, any trial that is not registered in ClinicalTrials.gov or another acceptable registry before the start of patient enrollment will not be considered for publication in a peer-reviewed journal. Ongoing trials were to be registered no later than September 13, 2005. The result has been just what the editors hoped for: a significant increase in the number of registered trials.

"The number of cancer trials submitted for registration in PDQ and ClinicalTrials.gov has literally exploded, climbing approximately tenfold between April and September of this year," said Dr. Richard Manrow, associate director of NCI's Office of Cancer Content Management, which maintains PDQ.

In an effort to keep the cancer trials listed in PDQ and ClinicalTrials.gov as synchronous as possible, the two registries regularly share trial information. ClinicalTrials.gov also prefers one source of submission for the clinical trials sponsored by each NIH institute or center. For NCI, PDQ is that source. Trials in PDQ are also listed on NCI's Web site, www.cancer.gov.