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Clinical trials are research studies in which people help doctors find ways to improve health and cancer care. Each study tries to answer scientific questions and to find better ways to prevent, diagnose, or treat cancer.
Types of Clinical Trials
Phases of Clinical Trials
Should I Take Part in a Clinical Trial?
Questions You Should Ask
• Treatment trials test new treatments (like a new cancer drug, new approaches to surgery or radiation therapy, new combinations of treatments, or new methods such as gene therapy).
• Prevention trials test new approaches, such as medicines, vitamins, minerals, or other supplements that doctors believe may lower the risk of a certain type of cancer. These trials look for the best way to prevent cancer in people who have never had cancer or to prevent cancer from coming back or a new cancer occuring in people who have already had cancer.
• Screening trials test the best way to find cancer, especially in its early stages.
• Quality of Life trials (also called Supportive Care trials) explore ways to improve comfort and quality of life for cancer patients.
Phases of clinical trials
Most clinical research that involves the testing of a new drug progresses in an orderly series of steps, called phases. This allows researchers to ask and answer questions in a way that results in reliable information about the drug and protects the patients. Clinical trials are usually classified into one of three phases:
Phase I trials: These first studies in people evaluate how a new drug should be given (by mouth, injected into the blood, or injected into the muscle), how often, and what dose is safe. A phase I trial usually enrolls only a small number of patients, sometimes as few as a dozen.
Phase II trials: A phase II trial continues to test the safety of the drug, and begins to evaluate how well the new drug works. Phase II studies usually focus on a particular type of cancer.
Phase III trials: These studies test a new drug, a new combination of drugs, or a new surgical procedure in comparison to the current standard. A participant will usually be assigned to the standard group or the new group at random (called randomization). Phase III trials often enroll large numbers of people and may be conducted at many doctors' offices, clinics, and cancer centers nationwide.
What Happens in a Clinical Trial?
In a clinical trial, patients receive treatment and doctors carry out research on how the treatment affects the patients. While clinical trials have risks for the people who take part, each study also takes steps to protect patients.
What Is It Like To Receive Treatment in a Study?
When you take part in a clinical trial, you receive your treatment in a cancer center, hospital, clinic, and/or doctor's office. Doctors, nurses, social workers, and other health professionals may be part of your treatment team. They will follow your progress closely. You may have more tests and doctor visits than you would if you were not taking part in a study. You will follow a treatment plan your doctor prescribes, and you may also have other responsibilities such as keeping a log or filling out forms about your health. Some studies continue to check on patients even after their treatment is over.
How Is the Research Carried Out? How Are Patients Protected?
In clinical trials, both research concerns and patient well-being are important. To help protect patients and produce sound results, research with people is carried out according to strict scientific and ethical principles. These include:
1. Each clinical trial has an action plan (protocol) that explains how it will work.
The study's investigator, usually a doctor, prepares an action plan for the study. Known as a protocol , this plan explains what will be done in the study and why. It outlines how many people will take part in the study, what medical tests they will receive and how often, and the treatment plan. The same protocol is used by each doctor that takes part.
For patient safety, each protocol must be approved by the organization that sponsors the study (such as the National Cancer Institute) and the Institutional Review Board , (IRB) at each hospital or other study site. This board, which includes consumers, clergy, and health professionals, reviews the protocol to try to be sure that the research will not expose patients to extreme or unethical risks.
2. Each study enrolls people who are alike in key ways.
Each study's protocol describes the characteristics that all patients in the study must have. Called eligibility criteria, these guidelines differ from study to study, depending on the research purpose. They may include age, gender, the type and stage of cancer, and whether cancer patients who have had prior cancer treatment or who have other health problems can take part.
Using eligibility criteria is an important principle of medical research that helps produce reliable results. During a study, they help protect patient safety, so that people who are likely to be harmed by study drugs or other treatments are not exposed to the risk. After results are in, they also help doctors know which patient groups will benefit if the new treatment being studied is proven to work. For instance, a new treatment may work for one type of cancer but not for another, or it may be more effective for men than women.
3. 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 a new treatment (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 new treatment 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 unknowns involved.
Phase III trials compare the results of people taking the new treatment with 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 treatment shows promise in Phases I and II. Phase III trials may include hundreds of people around the country.
4. In Phase III trials, people are assigned at random to receive either the new treatment or standard treatment.
Researchers assign patients by chance either to a group taking the new treatment (called the intervention group) or to a group taking standard treatment (called the control group). This method, called randomization, helps avoid bias: having the study's results affected by human choices or other factors not related to the treatments being tested.
In some studies, researchers do not tell the patient whether he or she is in the treatment or control group (called a single blind study). This approach is another way to avoid bias, because when people know what drug they are taking, it might change the way they react. For instance, patients who knew they were taking the new treatment might expect it to work better and report hopeful signs because they want to believe they are getting well. This could bias the study by making results look better than they really were.
Why Do Phase III Clinical Trials Compare Treatment Groups?
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 or has fewer side effects.
Another reason Phase III trials compare the new treatment with standard treatment is so that no one in a study is left without any treatment when standard treatment is available, which would be unethical. When no standard treatment exists for a cancer, some studies compare a new treatment with a placebo (a look-alike pill that contains no active drug). However, you will be told if this is a possibility before you decide whether to take part in a study.
Your Doctor Can Tell You More
If you have any questions about how clinical trials work, ask your doctor, nurse, or other health professional. It may be helpful to print this information and discuss points you want to understand better.
This is a question only you, those close to you, and your health professionals can answer together. Learning you have cancer and deciding what to do about it is often overwhelming. This section has information you can use in thinking about your choices and making your decision.
Weighing the Pros and Cons
While a clinical trial is a good choice for some people, this treatment option has possible benefits and drawbacks. 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 new treatment being tested, you will receive the best standard treatment. This may be as good as, or better than, the new approach.
If a new treatment approach 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.
New treatments 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 a new treatment 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 new treatment 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.
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 right away. 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.
Finding answers and making choices may be hard for people with cancer and those who care about them. It is important to discuss your treatment choices with your doctor, a cancer specialist (an oncologist) to whom your doctor may refer you, and the staff of any clinical trial you consider entering.
Ask questions about the information you receive during the informed consent process and about any other issues that concern you. Getting answers can help you work better with the doctor. You may want to take a friend or relative along when you talk to the doctor. It also may help to write down your questions and the answers you receive, or bring a tape recorder to record what is said. No question about your care is foolish. It is very important to understand your choices.
Here are some questions you may want to ask about:
What is the purpose of the study? In what phase is this study?
Why do researchers believe the new treatment being tested may be effective? Has it been tested before?
Who sponsors the study, and who has reviewed and approved it?
How are the study data and patient safety being checked?
When and where will study results and information go?
Possible Risks and Benefits
What are the possible short- and long-term risks, side effects, and benefits to me?
Are there standard treatments for my type of cancer?
How do the possible risks, side effects, and benefits in the study compare with standard treatment?
What kinds of treatments, medical tests, or procedures will I have during the study? Will they be painful? How do they compare with what I would receive outside the study?
How often and for how long will I receive the treatment, and how long will I need to remain in the study? Will there be follow-up after the study?
Where will my treatment take place? Will I have to be in the hospital? If so, how often and for how long?
How will I know if the treatment is working?
Will I be able to see my own doctor? Who will be in charge of my care?
How could the study affect my daily life?
Can you put me in touch with other people who are in this study?
What support is there for me and my family in the community?
Will I have to pay for any treatment, tests, or other charges?
What is my health insurance likely to cover?
Who can help answer any questions from my insurance company or managed care plan?
Others Can Help
As you make your treatment decisions, remember that you are not alone. Doctors, nurses, social workers, other people with cancer, clergy, family, and those who care about you can help and support you. The resources section also can provide more information and links to other contacts in your community.