Types of Studies

Clinical Study Types

There are several types of clinical studies (also called clinical trials), including treatment studies, quality-of-life studies, detection and diagnostic studies, prevention studies, and correlative studies.

Treatment Studies

A large number of clinical studies offered at Seattle Cancer Care Alliance (SCCA) are treatment studies. These studies attempt to find better ways to treat people with cancer or other diseases, and they are available for all stages of disease, from early to advanced.

The studies test new treatments or new ways of using current treatments, including drugs (such as chemotherapy agents, vaccines, blood products, or gene therapies), medical devices (such as infusion pumps), techniques for surgery or radiation therapy, or a combination of treatments, as well as no treatment or delayed treatment.

Quality-of-Life Studies

These studies typically explore and measure ways to use supportive care to improve the comfort and quality of life of patients and survivors. This may include ways to manage disease symptoms or ways to manage or decrease side effects associated with treatment. These studies may be:

  • Agent studies, in which the participant takes something—for example, a drug to improve mouth sores or lessen nausea
  • Action studies, in which the participant does something—such as begins an exercise regimen or makes dietary changes

Some studies are even designed to help families and caregivers cope with their needs. For example, a study might test whether spouses of women with breast cancer have less depression and anxiety and better communication with their spouse if they participate in an educational counseling program.

Detection and Diagnostic Studies

Detection and diagnostic studies test new ways of finding and identifying cancer or another disease early or with better accuracy. When cancer is found early, it may be easier to treat, and there may be a better chance for a cure.

  • Detection studies usually involve screening healthy volunteers who do not have any signs or symptoms of the disease being studied. Often these studies enroll participants who have a higher risk of developing the disease; for cancer, this may mean they are at higher risk as a result of their family history (genetics) or exposure to cancer-causing substances (carcinogens).
  • Diagnostic studies usually are trying to improve the accuracy of diagnosing a disease in people who have some signs or symptoms.

Prevention Studies

In cancer research, the goal of a prevention study is to find ways to prevent people from getting cancer in the first place or to prevent a recurrence or new cancer in people who have had the disease. In these studies, volunteers who don’t have cancer may be recruited to participate, often because they are at high risk, due either to genetics or to exposure to carcinogens. Participants may take something, such as a drug, or do something, such as change their diet, to lower their risk.

Most prevention studies compare groups of people while the study is underway, rather than waiting until the end of the study, to see if there is a difference. If there is a distinct benefit or risk to a particular group, the study will be stopped or changed so everyone receives the best option.

Correlative Studies

In addition to testing the safety and effectiveness of new interventions, clinical studies provide the opportunity for researchers to do correlative studies. These studies look for relationships between factors. The idea is that noticing trends and investigating them might improve doctors’ knowledge about how to prevent, detect, and treat a disease.

Correlative studies may use specimens from study participants, including their blood, tumor cells, or other tissue. Researchers must obtain permission from participants before using their specimens—which may have been taken before, during, or after treatment—for research purposes.

An example of a correlative study is one that compares biomarkers in a patient’s feces and blood to their colonoscopy results to see whether the biomarkers may be as accurate as a colonoscopy for detecting colon cancer early.