Cancer patients may participate in clinical trials to be among the first to benefit from new cancer treatments. Doctors organize research studies in three phases.
Popular perception about cancer research is facing new challenges as scientific breakthroughs like the mapping of the human genome pose ethical questions about the translation of basic research into effective therapies. Journalists often camp out on the doorstep of research institutions, waiting for news stories about “breakthrough” treatments that they will report on before the research community properly evaluates these discoveries. The public treats this news as credible information, and patients are sometimes disgruntled that their doctors are not topical enough to know about these new “miracle” pills or vaccines.
In order to make an informed decision about taking part in a cancer research study, it is helpful to understand how new treatment discoveries progress from basic research to standard treatment. Researchers conduct clinical trials in three phases, which each address new and increasingly complicated questions about the new treatment under study. Usually, a new cancer treatment will not advance to the next phase of study unless it has shown promise in the earlier phase. Proceeding through the three phases in an organized fashion allows researchers to protect the participants and ensure consistency and reliability in the study.
Phase I Clinical Trials
The main purpose of a phase I study is to examine the treatment for safety in humans and to determine the best way to administer the drug. The drug has already shown promise in animal or laboratory studies, and researchers have gathered some information about toxicity from these preliminary studies.
An advantage is the possibility of being one of the first people to benefit from a new treatment under study. However, very little may be known about long term side effects or how the cancer will respond to the drug, and because of these and other risks, phase I studies enroll small numbers of patients.
Phase II Clinical Trials
After phase I studies have established a safe dose for the new cancer drug, researchers initiate phase II studies to determine which cancers the treatment can target. Advantages of phase II studies include taking a drug that has an established toxicity level and some proven effect against cancer in humans. Phase II trials usually have a longer duration than phase I trials because the researchers must take more time to evaluate the tumor’s response to the drug.
Phase III Clinical Trials
Phase III studies compare the efficacy of the new treatment under study to the standard treatment for that type of cancer. Phase III trials may involve many hospitals across the country with hundreds of participants. Doctors usually assign patients at random to receive either the new treatment under study, or the standard treatment.
Typically, neither the patient nor the doctor will know which treatment the patient is receiving, in order to avoid any bias that might skew the results. As with all phases of clinical trials, you will discuss this and other aspects of the trial with your doctor when you sign the consent form that explains how researchers will conduct the trial.
Related Article: Ethical Issues in Clinical Trials
Source:
Dollinger, M., Rosenbaum, E.H., & Cable, G. (1994). Everyone's Guide to Cancer Therapy. Andrews and McMeel, Kansas City.
