Finding information on clinical trials, once a daunting and time–consuming task, has never been easier. Patients need no longer rely solely on their doctor for valuable information on treatment options, and researchers and other professionals can now instantly widen the scope of their searches for trials in their particular field, all with just a few mouse clicks.

Many Internet resources provide listings of current and prospective clinical trials, protocols and results of past trials, and overviews of the clinical trial system and patient–related information. These resources include web sites of government agencies, academic research centers and hospitals, and industry providers, including pharmaceutical and biotechnology companies, contract research organizations1, and listing services. Some are searchable either by therapeutic area and/or geographic region, while others offer an e–mail alert service to notify the subscriber of new trials in a specific field.

The best Internet sites usually have high traffic, and thus their information is more up–to–date. Clinical trials sites are no exception. The following is a short selection of the best clinical trial resources available on the Internet. By no means is it meant to be comprehensive; however, by following hyperlinks included on all the sites, one can emerge with an understanding of the breadth of this growing field.

CancerNet ( http://cancernet.nci.nih.gov/ ) is the clinical trials information center of the US National Cancer Institute. Containing information on over 1,600 open clinical trials, including all NCI–funded studies, this is the most comprehensive resource for locating clinical trials in the US. Posted information is reviewed regularly by oncology experts. The site also includes summaries on cancer treatment, screening, prevention, and supportive care, as well as a link to CancerLit, NCI's bibliographic database.

The award–winning OncoLink ( http://cancer.med.upenn.edu/clinical_trials/ ) was one of the first sources of cancer information on the Internet. Launched in March 1994 by the University of Pennsylvania Cancer Center, it has a comprehensive listing of Internet clinical trial resources, as well as a searchable database of all open UPCC clinical trials, frequently asked questions, and news.

CenterWatch ( http://www.centerwatch.com/ ) maintains a general database of clinical trials divided into four main sections: listings for more than 7,500 clinical trials, searchable by therapeutic area and geographic region; newly approved drug therapies; and research center and industry provider profiles. The site caters to patients interested in participating in trials, as well as research professionals, with features ranging from an e–mail patient notification service for new trial postings to the web site in a particular therapeutic area, to a listing of career opportunities in the clinical trials industry, upcoming conferences, and training seminars.

In Europe, TeleSCAN ( http://telescan.nki.nl ) is the first stop for information on European cancer research and treatment, providing links and information for the general public and for medical professionals and researchers. It is host to the UKCCCR/ ECCTR Register of Cancer Trials, the only extensive directory of cancer clinical trials in Europe, in collaboration with the Trials Office of the British Medical Research Council.

An engaging article written from the layperson's point of view that explains the clinical trial system can be found at http://www.cancerguide.org/clinical_trials.html . It offers a simple step–by–step outline of the structure of clinical trials, and the author, a cancer survivor and former participant in an interleukin–2 clinical trial, also offers firsthand tips for those choosing a study, such as requesting the protocol document from the doctor running the trial.