Clinical studies provide an alternative to traditional methods by providing new and innovative opportunities to help detect, prevent, treat and understand diseases. The standard care of treatment is the result of research that has been done previously.

Treatment options

Clinical studies are not just for people with no other treatment options. There certainly are some situations where research studies will involve new treatments that are not used for that particular cancer and a patient might want to consider that as an option and a physician might want to consider offering that as an option when there are no other good options available. However, the vast majority of research otherwise involves making what we currently know to be the best treatments available better, with less side effects or shorter in duration or to otherwise optimize and improve patients’ chances to be rid of the cancer or living longer and better as a result of the treatments. So they’re not always involving just a last resort.

Types of clinical studies

Treatment studies
Most cancer clinical studies are treatment studies. These studies compare standard treatments to new treatments, new ways of using existing treatments (such as new drugs, vaccines, surgery or radiation therapy) or combinations of treatments.

Prevention studies
These search for better methods in preventing diseases in those who have not been exposed and keeping the disease from coming back.

Quality of life studies
These are also called Supportive Care studies or Palliative Care studies. These studies look at ways to improve the quality of life of cancer patients by helping people cope with pain, nutrition problems, infection, nausea and vomiting, sleep disorders and depression.

Diagnostic study
These focus on discovering better ways for diagnosing diseases and conditions.

What are Cancer Research Studies?

Clinical study phases

Each kind of study goes through certain phases, but you (the patient) does not. These phases allow investigators to ask and answer questions to yield decisive information about the treatment with the safety of the patient in mind. There are four main phases:

Phase 1

This phase decides course of treatment including how often, dose amount and how dose will be provided.

  • Includes a small number of participants
  • Typically enrolls 15 to 30 patients
  • Purpose:
    • To find a safe dose of a new cancer medication
    • To decide how to give a new cancer treatment
    • To see how the new cancer treatment affects the human body

Phase 2

This phase tests the performance and effectiveness of the treatment.

  • Focuses on a specific kind of cancer
  • Typically enrolls less than 100 patients
  • Purpose:
    • To see if a new cancer treatment has an effect on a type of cancer
    • To see how a cancer treatment affects the body
    • Randomized treatment to one of two or more groups

Phase 3

This phase includes a comparison of preliminary treatment with standard methods.

  • Typically enrolls 100 to several thousand patients
  • Purpose:
    • To compare a new cancer treatment or use of a new cancer treatment
      with the standard treatment
    • Randomized treatment to one of two or more groups


In Phase 2 and Phase 3 clinical studies, patients are randomized (or randomly assigned) to different groups that receive different treatments. Randomization is a method used to ensure the research study is fair. It means that patients are assigned by chance to different treatment groups. Some people have found it helpful to view randomization to groups like the “sex of a baby,” A pregnant woman has an equal chance of giving birth to a male or female just like a patient has an equal chance of being assigned to a treatment group.

University of Michigan Comprehensive Cancer Center 

Center Watch

National Institutes of Health