There are several different types of cancer trials.
test experimental treatments, new drug combinations or new approaches to surgery or radiation.
Prevention trials, which study vaccines, drugs, vitamins or lifestyle changes, aim to prevent the disease or a recurrence of a disease.
Diagnostic trials validate techniques to better
diagnose stages of a disease.
Screening trials assess methods to detect early stages of a disease.
Quality of Life (or Supportive Care) trials evaluate ways to improve the quality of life for people with chronic diseases.Image: Computer artwork of a segment of beta DNA
Phases of Trials
Clinical trials occur in sequential phases, each of which serve a different function. Here is how the National Cancer Institute describes the trial phases:
In Phase I trials 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.
In Phase II trials, the experimental study 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.
In Phase III trials, the experimental study 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 the experimental drug or treatment to be used safely.
In Phase IV trials, post marketing studies delineate additional information including the drug’s risks, benefits, and optimal use.