Friday, July 3, 2009

What's New in Non-Small Cell Lung Cancer Research and Treatment?

Detailed Guide: Lung Cancer - Non-Small Cell
What's New in Non-Small Cell Lung Cancer Research and Treatment?

Lung cancer research is currently being done in medical centers throughout the world. Progress in prevention, early detection, and treatment based on current research is expected to save many thousands of lives each year.

Prevention

Tobacco

At this time, many researchers believe that prevention offers the greatest opportunity to fight lung cancer. Although decades have passed since the link between smoking and lung cancers was clearly identified, scientists estimate that smoking is still responsible for about 85% to 90% of lung cancer deaths. Research is continuing on:

  • ways to help people quit smoking through counseling, nicotine replacement, and other medicines
  • ways to convince young people to never start smoking
  • inherited differences in genes that may make some people much more likely to get lung cancer if they smoke or are exposed to someone else's smoke

Diet and nutrition

Although researchers are looking for ways to use vitamins or medicines to prevent lung cancer in people at high risk, these have so far not proved successful. For now, most researchers think that simply following the American Cancer Society dietary recommendations (such as maintaining a healthy weight and eating at least 5 servings of fruits and vegetables each day) may be the best strategy.

Early detection

In the past, large studies were done to determine whether routine chest x-rays and sputum cytology testing could save lives. Most researchers concluded that these tests did not find lung cancers early enough to significantly lower the risk of death from lung cancer. However, some researchers disagree about the best way to interpret the studies' data, and the debate continues.

A large clinical trial called the National Lung Screening Trial (NLST) is under way to test whether spiral CT scanning of people at high risk of lung cancer will save lives. The results of this study should be coming out in the next few years.

Another approach uses new, sensitive tests to detect cancer cells in sputum samples.

Researchers have recently found several changes that often affect the DNA of lung cancer cells. Current studies are looking at new diagnostic tests that specifically recognize these DNA changes to see if this approach is useful in finding lung cancers at an earlier stage.

Diagnosis

Virtual bronchoscopy

This imaging test uses CT scans to create detailed 3-dimensional pictures of the airways in the lung. The images can be viewed as if the doctor were actually using a bronchoscope.

Virtual bronchoscopy has some possible advantages over standard bronchoscopy. First, it is non-invasive and doesn't require anesthesia. It also allows doctors to see some airways that might not be visible with standard bronchoscopy, such as those being blocked by a tumor. But it has some drawbacks as well. For example, it doesn't show color changes in the airways that might indicate a problem. It also doesn't allow a doctor to take samples of suspicious areas like bronchoscopy does. Still, it can be a useful tool in some situations, such as in people who might be too sick to get a standard bronchoscopy.

This test will likely become more available as the technology improves.

Treatment

Stereotactic body radiation therapy (SBRT)

Stereotactic body radiation therapy (SBRT) is a newer type of treatment. It can be used for some very early stage (small) lung cancers when surgery isn't an option, usually for other medical reasons.

Instead of giving small doses of radiation each day for several weeks, SBRT involves giving very focused beams of high-dose radiation on one or a few days. Several beams are aimed at the tumor from different angles. In order to precisely target the radiation, the person is put in a specially designed body frame for each treatment. This reduces the movement of the lung tumor during breathing. Like other forms of external radiation, the treatment itself is painless.

Early results with SBRT have been very promising, and it seems to have a low risk of complications. But because it is still a fairly new technique, there isn't much long-term data on its use.

Chemotherapy

Many clinical trials in progress are comparing the effectiveness of newer combinations of chemotherapy drugs. These studies are also providing information about reducing side effects, especially in patients who are older and have other health problems.

Doctors know that adjuvant chemotherapy after surgery may be more helpful for some people with early (stage I or II) cancers than for others, but figuring out which patients to give it to is not easy. In early studies, newer lab tests that look at patterns of certain genes in the cancer cells have shown promise in telling which people might benefit most. Larger studies of these tests are now under way to try to confirm their usefulness. Doctors are also conducting clinical trials to search for better ways to combine chemotherapy with radiation therapy and other treatments.

Targeted therapies

Researchers are learning more about the molecules within lung cancer cells that control their growth and spread. This is being used to develop new targeted therapies. Some of these treatments are already being used to treat non-small cell lung cancer. Others are now being tested in clinical trials to see if they can help people with advanced lung cancer live longer or relieve their symptoms.

Some of the drugs that are in late stage clinical trials include vandetanib (ZD6474, Zactima), DMXAA (ASA404), and motesanib (AMG 706). Some targeted drugs already approved for use against other types of cancer, such as sorafenib (Nexavar) and sunitinib (Sutent), are also being tested for use against NSCLC.

Researchers are also working on lab tests to help predict which patients will benefit from which drugs. Several clinical trials have already reported that some patients do not benefit from certain targeted therapies, whereas others have quite remarkable shrinkage of their tumors. Predicting who might benefit could save some people from trying treatments that are unlikely to work for them and would likely cause unneeded side effects.

Vaccines: Several types of vaccines for boosting the body's immune response against lung cancer cells are being tested in clinical trials. Unlike vaccines against infections like measles or mumps, these vaccines are designed to help treat, not prevent, lung cancer. One possible advantage of these types of treatments is that they seem to have very limited side effects, so they might be useful in people who can't tolerate other treatments.

Some vaccines are made up of lung cancer cells that have been grown in the lab, or even of cell components, such as parts of proteins commonly found on cancer cells. For example, L-BLP25 (Stimuvax) is a vaccine made up of a piece of a protein (MUC1) that is encased in a fat droplet (liposome) to make it more effective. A small study of patients with advanced NSCLC suggested it may improve survival time. Larger studies are under way to confirm this.

At this time, vaccines are only available in clinical trials.

No comments:

Post a Comment