There are many kinds of clinical trials. They range from studies of ways to prevent, detect and diagnose, control and treat cancer, to studies of the psychological impact of the disease and ways to improve the patient's comfort and quality of life (including pain control). Most cancer clinical trials deal with new treatments.

Clinical trials are, ideally, a part of a system in which a series of scientifically-controlled experiments shepherd a plausible agent, combination of agents or procedure through a process whereby the efficacy of the agent or procedure is established or not. In the U.S. this process is overseen by the Food and Drug Administration ("FDA").

Treatment trials test experimental treatments, new combinations of drugs, or new approaches to surgery or radiation therapy. Prevention trials look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include medicines, vitamins, vaccines, minerals, or lifestyle changes. Diagnostic trials are conducted to find better tests or procedures for diagnosing a particular disease or condition.

Three clinical trials conducted worldwide involved 4,578 women of who 3,319 used Ortho Evra. The other women in the trials used birth control pills. The trials demonstrated that women using Ortho Evra were able to adhere to the once a week dosing regimen as an alternative to a daily dose of birth control pills. In clinical trials, Ortho Evra appeared to be less effective in women weighing more than 198 pounds.

The process of drug development begins in the laboratory. New approaches to treatment are tested for several years—first in the test tube, then in living systems or models. These early tests are called “preclinical” research. If this research proves promising, researchers will ask for approval from the Food and Drug Administration (FDA) to begin clinical trials with patients. Clinical trials with patients are done in phases.

It is important to understand the clinical trial process, as well as the features of the particular trial you are considering, before you agree to become a participant. For further information, the website clinicaltrials.gov includes a list of questions to ask about trial participation, and links to additional resources. Also, remember that you should discuss trial participation with your healthcare provider, as well as with your loved ones.

The reliability or "strength of evidence" of a clinical study depends on two major variables 1) who performed the study; 2) the design of the study. In respect to who performed the study, investigator bias can play a role in how the outcomes are reported. It is very difficult to determine if and when there are real conflicts of interest.

a cancer patient, you may take part in a clinical trial. This information is provided for you, your family and friends, to explain what clinical trials are and to help you make a decision about entering a trial. The time when cancer is diagnosed or when treatment decisions are being made is very difficult. It is often hard to understand or remember complex medical explanations. This information is meant to supplement what your doctors tell you.

Advances in medicine and science are the results of new ideas and approaches developed through research. New cancer treatments must prove to be safe and effective in scientific studies with a certain number of patients before they can be made widely available. Through clinical trials, researchers learn which approaches are more effective than others. This is the best way to test a new treatment. A number of standard treatments were first shown to be effective in clinical trials.

Yes. The treatments used in clinical trials can cause side effects and other health risks depending on the type of treatment and the patient's condition. Side effects vary from patient to patient. Because clinical trials are research into new areas of treatment, the risks involved are not always known ahead of time, though efforts have been made to find out what they might be. For this reason, trials can carry unknown dangers and side effects as well as hoped-for benefits.