Dear Doctor: I keep reading about new cancer drugs that have been developed in clinical trials. What exactly is a clinical trial and how does it work?

Dear Reader: A clinical trial is a scientific study that looks into whether a specific drug, medical treatment, device or approach is not only effective, but also safe. Although clinical trials for new drugs often get the most press, other important advances arise from the process. New ways to screen for disease, new methods of diagnosis, and techniques that will improve the quality of life for people living with disease are all important advances made in clinical trials.

New therapies are tested in treatment trials. Prevention trials investigate methods of lowering disease risk. In screening trials, optimal methods to discover the onset of disease are tested. Supportive care trials focus on quality of life for patients with debilitating disease. Diagnostic trials focus on tests and procedures to pinpoint the exact type of cancer or condition a patient has.

So how does a clinical trial work?

It starts with an idea. A researcher or doctor or other expert comes up with a "what if?" scenario. For example, what if it's possible to develop a drug to help a patient's own immune system fight cancer?

The next step is extensive laboratory testing. If the idea continues to show promise, research moves into a clinical trial.

A detailed plan, known as a protocol, is created. It states who is eligible to take part in the clinical trial, details all of the tests and procedures that will be performed, names the drugs that will be involved, and describes how the drugs will be administered. The protocol also indicates the length of the clinical trial, and how the information will be collected and collated.

Clinical trials are conducted in four distinct phases that may take place over the course of several years. They begin with Phase 1, which is initial testing on a small group of participants to assess safety and identify side effects. In Phases 2 and 3, the new drug or treatment is given to ever-larger groups of people to further evaluate safety and efficacy. By Phase 4, the drug or treatment has been approved by the FDA and is now evaluated in a large population.

If you're thinking about joining a clinical trial, you should know:

-- The specific purpose of the study;

-- Why researchers believe the experimental therapy will be effective;

-- What drugs, tests or procedures the trial entails;

-- Any risks or potential side effects of the treatment;

-- How much time is required;

-- How your daily life will be affected;

-- How you will know whether the therapy is successful.

It's not an exaggeration to say that clinical trials are at the heart of modern medical advances. Many of the cancer treatments that are saving or extending lives today began as a "what if?" idea in a clinical trial. And while participants may join in hopes of being on the receiving end of a medical advance, they also have the satisfaction of knowing that they are contributing to the body of knowledge that will make medicine even more effective in the future.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

Dear Doctor: A news report recently said that statins are underused. I'm 50 with normal cholesterol. Should I take one just in case?

Dear Reader: Statins, which are a type of cholesterol-lowering medication, have consistently shown benefit in reducing the risk of heart attacks and strokes in people who have had a previous heart attack or angina. This benefit is called secondary prevention. Statins have also shown benefit in people with risk factors for heart disease who have never had a heart attack; smokers; and people with diabetes, hypertension or a family history of heart disease. This is called primary prevention.

In people like yourself, the potential benefit of statin use is not as clear-cut. So, first, let's look at the Jupiter study, published in 2008. The 17,802 people in this study had normal cholesterol levels -- that is, an LDL score (for low-density lipoprotein, the so-called "bad cholesterol") of less than 130 -- but they had an elevated level of highly sensitive C-reactive protein (CRP), a marker for both inflammation and a heightened risk of coronary artery disease.

Researchers divided participants into two groups, with one group taking a daily placebo and the other group taking a daily 20-milligram dose of rosuvastatin. The study was stopped in less than two years because of the significant benefit seen in the group that took the statin.

The study authors found a 44 percent decrease in deaths from heart attacks and strokes and a 20 percent decrease in the total death rate among the group who took the statin. Not only did participants who took rosuvastatin show a reduction in cholesterol, they also showed a decrease in their levels of highly sensitive CRP. That suggests that statins reduce both cholesterol and the inflammation that may lead to vascular disease.

Now let's look at what to consider if your CRP level is normal and you have normal cholesterol. A 2001 study in the New England Journal of Medicine followed 6,605 men and women in Texas who had either normal CRP levels or abnormal CRP levels. One group was given a statin, called lovastatin, and the other group was given a placebo. Although there was a benefit seen with lovastatin among those who had an elevated CRP level, the benefit was not seen in those who had a normal CRP level.

One conclusion from the data is that if you have normal cholesterol and no other risk factors, you should have your doctor check your levels of highly sensitive CRP. If the CRP is persistently elevated, then there is likely benefit to a cholesterol-lowering medication. One word of caution, however: If you have inflammation related to either infection or an autoimmune condition, the CRP will be elevated because of those conditions and therefore won't be a reliable marker.

Doctors currently assess the need for statins by looking at risk calculators. These risk calculators assess an individual's risk of having a heart attack over the next 10 years. Some doctors recommend that people start statins if their 10-year risk of a heart attack is 7.5 percent. So if you're a healthy 55-year-old man with normal cholesterol and a blood pressure of 125/70, your calculated risk would be 7.83 percent -- and many doctors would recommend a statin. However, the science behind the risk calculator is poor, with a large Kaiser Permanente study of 307,000 people showing that it may significantly overestimate risk.

That finding emphasizes the need for the CRP test. If that test is normal, a statin would be unlikely to provide any benefit to you.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

Dear Doctor: My husband, who never met a gadget he didn't like, wants our family to switch from regular toothbrushes to electric ones. He insists it's worth the cost because electric toothbrushes do a better job. Is he right, or is this just an excuse for another fun toy?

Dear Reader: Can it be both? Research in the last few years shows that your gadget-loving spouse is right -- electric toothbrushes do have an edge over the muscle-powered variety when it comes to keeping plaque and gingivitis at bay. Add in the fact that kids seem to enjoy the noise and buzz, and that for the elderly or those with arthritis these toothbrushes are easier to use, and the electric variety deserves a closer look.

The key to good oral health is a regular routine of brushing your teeth to remove plaque. That's the soft, sticky film that builds up in the mouth and which contains millions of bacteria. Those bacteria contribute to gum disease and tooth decay, which are the primary causes of tooth loss. Keeping your teeth free of plaque (and keeping the spaces between your teeth free of debris) is essential.

When used properly, the manual toothbrush is a very effective tool. Also, it's a fraction of the cost of an electric, which starts in the $20 range and goes (way) up from there.

However, in multiple studies in which researchers followed two groups, one that used manual toothbrushes and another group that used the electric variety, differences arose. At the end of three months, the group using an electric toothbrush showed 20 percent better plaque removal and 11 percent less gingivitis than the group using the manual toothbrush. In studies that ran six months and longer, the benefits of the electric toothbrush were even more pronounced.

The differences don't end there.

Electric toothbrushes fall into two different categories, those that spin and those that vibrate. Spinning brushes average from 2,500 up to 7,000 strokes per minute, depending on the model. The vibrating variety, also known as sonic brushes, move at up to 40,000 strokes per minute.

Studies show (yes, there are studies for just about everything) that, when used for six months or longer, the sonic variety of electric toothbrush was better than the rotating type at reducing inflammation due to gingivitis.

Of course none of these kinds of toothbrush will do much good if they're used improperly or not at all. Technique and timing are everything. Be sure to spend a full two minutes per session and brush the front, back and chewing surface of each tooth. Don't forget about your molars, which can be hard to reach. And note that, for an electric toothbrush, brush heads need to be replaced on a regular basis.

One final thought -- with so many small battles to be fought when it comes to children and hygiene, the fact that kids (of all ages) seem to enjoy electric toothbrushes might be a point in the plus column.

The sound, motion and sensation, to say nothing of the many fanciful shapes and colors now available in kids' toothbrushes, achieve the seemingly impossible. That is, they make brushing your teeth fun.

(Eve Glazier, M.D., MBA, is an internist and assistant professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health.)

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)