Frequently Asked Questions

The University of Arizona Cancer Center, a National Cancer Institute-designated Comprehensive Cancer Center, is one of the leading sites in the country for the treatment of cancer. In addition to receiving state-of-the-art, evidence-based multidisciplinary cancer care, our patients have access to novel targeted therapy medications and innovative treatments through clinical trials.

Clinical trials are scientific studies in which people volunteer to participate under the supervision of physicians and research professionals. In the realm of cancer, therapeutic clinical trials examine new medications, new combinations of drugs or new approaches to surgery or radiation therapy. However, clinical trials may also study new diagnostic and screening methods as well as prevention and quality of life strategies.

In therapeutic trials, new treatments, which on average have at least six years of research behind them, are tried in a small number of patients in order to determine safety and effectiveness before they can be made widely available. Many standard treatments used today are the result of past clinical trials, which involve a strict and rigorous, multi-step process that takes eight years on average to complete. Clinical trials are monitored by the National Institutes of Health and the U.S. Food and Drug Administration as well as by local oversight boards that ensure volunteers’ rights are preserved.

Inclusion and exclusion criteria, such as age, disease type, medical history and current medical condition, are used to identify appropriate participants for a clinical trial and help researchers ensure they can answer the questions they plan to study. Before patients decide to enroll in a trial, they learn about a study's treatments and tests, and possible benefits and risks, but participants can also withdraw from a study at any time.

Choosing to participate in a clinical trial is an important personal decision. Patients interested in clinical trials should read these frequently asked questions and talk to their physician. For more information about clinical trials at the University of Arizona Cancer Center, please call (866) 278-1554.

How does a clinical trial work?

A volunteer is usually assigned a specific study group. Volunteers in one study group may receive an investigational treatment or drug while other volunteers may receive a standard treatment, sometimes a placebo, an inactive product, is used with a standard treatment to assess the effectiveness of the experimental treatment. The group in which a volunteer is placed may not be known to those involved in the study, which allows researchers to objectively observe and evaluate the volunteers. Regardless of which treatment volunteers receive, the level of medical attention and care received is the same.

What are the different types of clinical trials?

  • Treatment trials – test experimental treatments, new combinations of drugs or new approaches to surgery or radiation therapy.
  • Prevention trials – look for better ways using medicines, vaccines, vitamins, minerals or lifestyle changes to prevent a disease from occurring or returning.
  • Diagnostic trials – look for better tests or procedures for diagnosing a disease or condition.
  • Screening trials – look for better methods to detect diseases or health conditions.
  • Quality of Life trials (or Supportive Care trials) – look for ways to improve comfort and the quality of life for individuals with chronic illnesses.

What are clinical trial phases?

Each phase of the clinical trial process has a different purpose and is treated as a separate study. After completion of a phase, investigators must submit data for approval from the FDA before continuing to the next phase.

  • Phase I - researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range and identify side effects.
  • Phase II - the experimental drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
  • Phase III - the experimental drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments and collect information that will allow it to be used safely.
  • Phase IV – studies occur after an approved drug is on the market to delineate additional information including the drug's risks, benefits and optimal use.

Who can participate in a clinical trial?

Eligible participants are determined by a clinical trial’s inclusion and exclusion criteria, which are based on factors such as age, disease type, medical history and current medical condition. Some studies seek volunteers with a particular illness to be studied, while other trials recruit healthy volunteers. The criteria are used to identify appropriate participants and help researchers ensure they can answer the questions they plan to study.

What protections exist for clinical trial participants?

An Institutional Review Board comprised of scientists and non-scientists of varied backgrounds, genders and ethnicities review all human subject research conducted at the Arizona Cancer Center to ensure that studies are ethical and participants are not likely to be harmed. The IRB can stop a study if it appears to be causing unexpected harm to participants or if it is clear that the new treatment is effective and should be made more widely available.

What is informed consent?

Doctors and nurses involved in a trial explain the details of a study to interested candidates using terms the potential participants will understand. Candidates receive an informed consent document that includes a detailed description of what's expected of a volunteer as well as details such as the trial’s purpose, duration, required procedures, risks, potential benefits and key contacts. Candidates then decide whether to sign the document and agree to participate in the trial. A participant can withdraw from a study at any time without penalty.

What questions should be asked before choosing to participate?

  • How long will the trial last?
  • Where is the trial being conducted?
  • What treatments will be used and how?
  • What is the main purpose of the trial?
  • How will patient safety be monitored?
  • Are there any risks involved?
  • What are the possible benefits?
  • What are the alternative treatments besides the one being tested in the trial?
  • Who is sponsoring the trial?
  • Do I have to pay for any part of the trial?
  • What happens if I am harmed by the trial?
  • Can I opt to remain on this treatment, even after termination of the trial?

What are the possible benefits of joining a trial?

  • Access to promising new interventions that are generally not yet available to the public and may be more effective than standard therapy.
  • Receive highly specialized and monitored medical care and attention.
  • Help others by contributing to medical research.

What are the possible risks of joining a trial?

  • Experimental treatment may not be more effective than standard treatment or may have unexpected side effects.
  • May require more trips to the study site or more treatments.

What happens after the trial?

The data collected from the study is used to determine the therapy’s effectiveness, safety and side effects. Researchers then determine whether to move on to the next phase of study. After Phase III of a study is complete, data may be submitted to the FDA for approval. If a drug is approved, pharmaceutical companies may continue to conduct studies that compare the new drug to other drugs already on the market or assess a drug's long-term effectiveness and impact on the quality of a person's life.

How can I find out more?

Choosing to participate in a clinical trial is an important personal decision. Patients interested in clinical trials should talk to their physician. Search a list of open therapeutic trials at the University of Arizona Cancer Center. A searchable registry of clinical trials around the world is available at