Clinical Trials: Why, Who, and How

Clinical Trials: Why, Who, and How

What Are Clinical Trials?

Clinical trials are carefully conducted research studies that evaluate the performance of new medical treatments or devices. These trials test the effectiveness and side effects of new medicines, medical devices, and surgical procedures. They sometimes also look at new ways to use existing treatments (for example, drugs, surgical procedures, and devices). Clinical trials have strict oversight in place to ensure the safety of study volunteers.

There are 4 different phases of clinical trials:

  • Phase I clinical trials include a small group of people to test an experimental drug or treatment and determine its safety and side effects. Phase 1 cancer studies often involve patients who have widespread cancer for which other standard treatments have failed.
  • Phase II clinical trials involve a larger group of selected patients and provide the experimental drug or treatment to check its effectiveness.
  • Phase III clinical trials involve an even larger, more diverse group of patients and compare the effectiveness of the experimental drug or treatment to standard treatment and confirm the Phase 2 findings in a larger patient population.
  • Phase IV clinical trials occur after a treatment is widely available to patients or, in the case of a new drug, when the drug has met FDA approval and monitor rare or long-term side effects in the larger population over time.

Patients are provided detailed information about a clinical trial before enrolling and sign a detailed informed consent before participating. During the clinical trial, patients are closely monitored by their medical team. Depending on the design of the trial, a patient may be randomized (similar to the flip of a coin, usually done with computer randomization) to receive the experimental treatment, the standard treatment, placebo treatment, or no treatment. There is no guarantee that participation in a clinical trial will benefit a patient on an individual level and in clinical trials, just as with any medical treatment or device, there can be side effects. Patients may stop their participation in a clinical trial at any time.

Why Participate in a Clinical Trial?

Patients choose to participate in a clinical trial for many reasons, including:

  • Having access to new, potentially beneficial treatments that are otherwise not available to them
  • Making a difference for their family members who may have a particular disease or be at risk of a particular disease
  • Helping  advance medical knowledge

Clinical trials have been the key to advancements in the treatment of disease, especially in the field of breast cancer surgery. Most of the common surgical treatments for breast cancer, such as the use of lumpectomy and radiation therapy rather than radical mastectomy, and sentinel lymph node biopsy rather than routine axillary dissection, came about through clinical trials. It is also through clinical trials that the treatment of breast cancer patients will continually be improved. 


File Progress in Breast Cancer Surgery Through Clinical Trials (PDF) (107.8KB)

Finally, studies have shown that patients with cancer who participate in clinical trials have improved outcomes when compared to those who receive treatment without any clinical trial enrollment.1


1.Unger JM, Barlow WE, Martin DP, et al. Comparison of survival outcomes of cancer patients treated in and out of clinical trials. J Natl Cancer Inst. 2014;3:dju002. doi: 10.?1093/?jnci/?dju002