Clinical Trial Basics

Clinical Trials are in-depth medical research studies conducted to understand whether promising approaches to cancer prevention, diagnosis and treatment are safe and effective.


Cancer Research Includes Four Types of Trials

  • Treatment: research to test new approaches to treatment including new drugs, drug combinations, radiation and surgery
  • Prevention: research to investigate methods to prevent the disease from occurring in people who have previously not had cancer; or prevent the cancer from recurring in patients who previously have been diagnosed with the disease
  • Screening: research to find the optimum approach in detecting cancer before symptoms occur; includes imaging , laboratory and genetic testing
  • Quality of Life: research to investigate means of improving cancer patients' and survivors' quality of life; areas explored include the management of fatigue, nausea, pain, weight loss and depression associated with cancer treatments

Clinical Trial Phases

Clinical trials progress through a series of stages meant to ensure safety of patient and effectiveness of treatment:

  • Phase I: a drug or treatment is initially evaluated with a limited group (approximately 20-30) to determine its safety, optimal dose or treatment levels and identify side effects
  • Phase II: the experiemental study's drug or treatment is tested for safety and effectiveness and usually involves a larger number of participants (approximately 100-300) compared to Phase I
  • Phase III: the experimental study's drug or treatment is given (administered) to confirm findings of Phase II and to compare it to existing treatments. A greater amount of information is collected in order to determine the safety of the drug or treatment (typically involves 1,000-3,000 participants)
  • Phase IV: after the drug or treatment gains FDA approval, the study enters the marketing stage. This study observes the drug or treatment over a lengthy time period and involves a significantly larger number of participants (thousands). The purpose is to evaluate side effects, risks and benefits of a drug; and is typically conducted by the drug maker

Patient Benefits

  • Health care professionals play an active role in the patient’s health care
  • Patients have access to new treatments before being widely introduced
  • Patients receive top-level care at leading medical institutions
  • Patients play a valuable role in medical research with the potential to help other patients facing similar health challenges

Patient Risks

  • There is the potential for unpleasant side effects, including headache, nausea, hair loss or skin irritation
  • The treatment may not be effective or produce the desired result
  • Participation in a trial may involve a greater time commitment than pursuing non-trial treatment

Participation and Screening Process

The clinical trial, which includes doctors, nurses and other health care professionals, involves an initial review of the patient’s condition or overall health, monitoring the patient during the trial, and maintaining post-trial contact with the patient.

Before performing any of the study’s related procedures, the research team provides the patient with the complete information necessary to make a proper decision about participating in the study. The process is known as the informed consent. It is mandatory that a patient sign an informed consent form (ICF) before the research team performs any procedures.

After the ICF is signed, the patient begins the screening process, which determines participation eligibility. Each study includes a list of inclusion and exclusion criteria and a unique list tailored to the respective treatment being studied.

More Trial Information

  • Participatory guidelines exist, and these are commonly known as “inclusion/exclusion criteria.”
  • All U.S. clinical trials are approved and tracked by an institutional review board to ensure risks are as minimal as possible and are worth the benefits.
  • Participants should be well-informed and understand as much as possible about the clinical trial and should feel comfortable asking questions.

Questions to Ask About Clinical Trials

  • Who is in the study?
  • How do the potential side effects and benefits compare with my current treatment?
  • How might this trial affect my daily life?
  • Will hospitalization be required?
  • Who will be in charge of my care?