Search the Health Library
Get the facts on diseases, conditions, tests and procedures.
I Want To...
I Want To...
Find Research Faculty
Enter the last name, specialty or keyword for your search below.
School of Medicine
What Are Cancer Clinical Trials?
Clinical trials for cancer, also called cancer treatment or cancer research studies, test new treatments in people with cancer. The goal of this research is to find better ways to treat cancer and help cancer patients. Clinical trials test many types of treatment such as: new drugs; new approaches to surgery or radiation therapy; new combinations of treatments; or, new methods, such as gene therapy.
A cancer clinical trial is one of the final stages of a long and careful research process. The search for new treatments begins in the laboratory, where scientists first develop and test new ideas. If an approach seems promising, the next step may be testing a treatment in animals to see how it affects cancer in a living being and whether it has harmful effects. Of course, treatments that work well in the lab or in animals do not always work well in people. Studies are done with cancer patients to find out whether promising treatments are safe and effective.
Cancer clinical trials include research at three different phases. Each phase answers different questions about the new treatment.
- Phase I trials are the first step in testing a new treatment in humans. In these studies, researchers look for the best way to give an experimental drug (e.g., by mouth, IV drip, or injection; how many times a day). They also try to find out if and how the treatment can be given safely (e.g., best dose), and they watch for any harmful side effects. Because less is known about the possible risks and benefits in Phase I, these studies usually include only a limited number of patients who would not be helped by other known treatments.
- Phase II trials focus on learning whether the experimental drug has an anticancer effect (e.g., Does it shrink a tumor? Improve blood test results?). As in Phase I, only a small number of people take part because of the risks and unknown variables involved.
- Phase III trials compare the results of people taking the experimental drug with the results of people taking standard treatment (e.g., Which group has better survival rates? Fewer side effects?). In most cases, studies move into Phase III testing only after a drug shows promise in Phases I and II. Phase III trials may include hundreds of people around the country. Comparing similar groups of people taking different treatments for the same type of cancer is another way to make sure that study results are real and caused by the treatment, rather than by chance, or other factors. Comparing treatments with each other often shows clearly which one is more effective and/or has fewer side effects.
Why Are Clinical Trials Important?
Clinical trials are important in two ways. First, cancer affects us all, whether we have it, care about someone who does, or worry about getting it in the future. Clinical trials contribute to knowledge and progress against cancer. If a new treatment proves effective in a study, it may become a new standard treatment that can help many patients. Many of today's most effective standard treatments are based on previous study results, such as those for breast, colon, rectal, and childhood cancers.
Clinical trials may also answer important scientific questions and suggest future research directions. Because of progress made through clinical trials, many people treated for cancer are now living longer.
Second, the patients who take part may be helped personally by the treatment(s) they receive. They get up-to-date care from cancer experts, and they receive either a new treatment being tested or the best available standard treatment for their cancer. Of course, there is no guarantee that a new treatment being tested or a standard treatment will produce good results. New treatments also may have unknown risks.
But, if a new treatment proves effective, or more effective, than standard treatment, study patients who receive it may be among the first to benefit. Many patients receiving standard treatment benefit from it.
In the past, clinical trials were sometimes seen as a last resort for people who had no other treatment choices. Today, patients with common cancers often choose to receive their first treatment in a clinical trial.
Your Rights, Your Protections
Before and during a cancer treatment study, you have a number of rights. Knowing these can help protect you from harm.
Taking part in a treatment study is up to you. It may be only one of your treatment choices. Talk with your doctor. Together, you can make the best choice for you.
If you do enter a study, doctors and nurses will follow your response to treatment carefully throughout the research.
If researchers learn that a treatment harms you, you will be taken off the study immediately. You may then receive other treatment from your own doctor. You have the right to leave a study at any time.
One of your key rights is the right to informed consent. Informed consent means that you must be given all the facts about a study before you decide whether to take part. This includes details about the treatments and tests you may receive and the possible benefits and risks they may have.
The doctor or nurse will give you an informed consent form that goes over key facts. If you agree to take part in the study, you will be asked to sign this informed consent form.
The informed consent process continues throughout the study. For instance, you will be told of any new findings regarding your clinical trial, such as new risks. You may be asked to sign a new consent form if you want to stay in the study.
Signing a consent form does not mean you must stay in the study. In fact, you can leave at any time. If you choose to leave the study, you will have the chance to discuss other treatments and care with your own doctor or a doctor from the study.
Who is Eligible to Participate?
Each study has its own guidelines for who can participate, called eligibility criteria. Generally, participants in a study are alike in key ways, such as the type and stage of cancer, age, gender, or previous treatments. The eligibility criteria are included in the study plan. To find out if you are eligible for a particular study, talk to your doctor or the doctor or nurse in charge of enrolling patients in the study.
The Pros and Cons
While a clinical trial is a good choice for some people, this treatment option has possible drawbacks as well as potential benefits. Here are some factors to consider. You may want to discuss them with your doctor and the people close to you.
Clinical trials offer high-quality cancer care. If you are in a study and do not receive the experimental option being tested, you will receive the best standard treatment. This may be as good as, or better than, the new approach. If an experimental option is proven to work and you are taking it, you may be among the first to benefit.
By looking at the pros and cons of clinical trials and your other treatment choices, you are taking an active role in a decision that affects your life.
You have the chance to help others and improve cancer treatment.
Experimental options under study are not always better than, or even as good as, standard care. They may have side effects that doctors do not expect or that are worse than those of standard treatment.
Even if an experimental drug has benefits, it may not work for you. Even standard treatments, proven effective for many people, do not help everyone.
If you receive standard treatment instead of the experimental one being tested, it may not be as effective as the new approach.
Health insurance and managed care providers do not always cover all patient care costs in a study. What they cover varies by plan and by study. To find out in advance what costs are likely to be paid in your case, talk to a doctor, nurse or social worker from the study.
Who Pays for the Patient Care Costs?
Even if you have health insurance, your coverage may not include some or all of the costs associated with a clinical trial. This is because some health plans define clinical trials as "experimental" or "investigational" procedures. However, they may be willing to pay if the experimental option is similar to a standard treatment. Because lack of coverage for these costs can keep people from enrolling in trials, the National Cancer Institute is working with major health plans and managed care groups to find solutions.
*Source: National Cancer Institute