Prevention trials
Prevention trials test new approaches such as medications, vitamins, or other supplements that doctors believe may lower the risk of developing a certain type of cancer. Most prevention trials are conducted with healthy people who have not had cancer.

Screening trials
Screening trials study ways to detect cancer or pre-cancer condition earlier. They are done to determine whether finding cancer before it causes symptoms decreases the chance of dying from the disease. These trials involve people who do not have any symptoms or a diagnosis of cancer.

Diagnostic trials
Diagnostic trials explore study tests or procedures that could be used to identify cancer earlier and more accurately.

Treatment trials
Treatment trials usually involve people who have cancer. They are designed to answer specific questions about the safety and effectiveness of a new treatment or intervention in treating or in some cases preventing cacer. These trials may test many types of treatments such as new drugs, vaccines, new approaches to surgery or radiation therapy, or new combinations of treatments.

Quality-of-life trials
Quality-of-life (also called Supportive Care or Palliative Care) Trials explore ways to improve the comfort and quality of life of cancer patients and cancer survivors such as ways to minimize the short- and long-term side effects of cancer-related treatment.

Pre-clinical phase
Preclinical phase is the early discovery and ongoing research conducted in the laboratory.

Phase 1
Phase 1 clinical trials are studies aimed at determining the safety of an intervention and in the case of a medicine, the optimal dose.

Phase 2
Phase 2 clinical trials are aimed at determining the effectiveness and safety of an intervention.

Phase 3
Phase 3 clinical trials are aimed at determining whether a specific intervention is better, worse, or equally effective as the accepted standard of care. In many cases this type of trial is needed to determine FDA approval.