What’s new in small cell lung cancer research and treatment?
Prevention offers the greatest opportunity to fight lung cancer. Although decades have passed since the link between smoking and lung cancers became clear, smoking is still responsible for at least 80% of lung cancer deaths, and this percentage is likely even higher for small cell lung cancers. Research is continuing on:
- Ways to help people quit smoking and stay quit 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
Researchers also continue to look into some of the other causes of lung cancer, such as exposure to radon and diesel exhaust. Finding new ways to limit these exposures could potentially save many more lives.
Diet, nutrition, and medicines
Researchers are looking for ways to use vitamins or medicines to prevent lung cancer in people at high risk, but so far none have been shown conclusively to reduce risk.
Some studies have suggested that a diet high in fruits and vegetables may offer some protection, but more research is needed to confirm this. While any protective effect of fruits and vegetables on lung cancer risk is likely to be much less than the increased risk from smoking, following the American Cancer Society dietary recommendations (such as maintaining a healthy weight and eating a diet high in fruits, vegetables, and whole grains) may still be helpful.
As mentioned in the section “Can small cell lung cancer be found early?”, a large clinical trial called the National Lung Screening Trial (NLST) found that spiral CT scans in people at high risk of lung cancer (due to smoking history) lower the risk of death from lung cancer, when compared to chest x-rays. This finding has led to the development of screening guidelines for lung cancer.
Another approach now being studied uses newer, more sensitive tests to look for cancer cells in sputum samples. Researchers have found several changes often seen in the DNA of lung cancer cells. Current studies are looking at new tests that can spot these DNA changes to see if they can find lung cancers at an earlier stage.
Also known as autofluorescence bronchoscopy, this technique may help doctors find some lung cancers earlier, when they may be easier to treat. For this test, the doctor inserts a bronchoscope through the mouth or nose and into the lungs. The end of the bronchoscope has a special fluorescent light on it, instead of a normal (white) light.
The fluorescent light causes abnormal areas in the airways to show up in a different color than healthy parts of the airway. Some of these areas might not be visible under white light, so the color difference may help doctors find these areas sooner. Some cancer centers now use this technique to look for early lung cancers, especially if there are no obvious tumors seen with normal bronchoscopy.
This imaging test uses CT scans to create detailed 3-dimensional pictures of the airways in the lungs. The images can be seen 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 helps doctors look at some airways that might not be seen 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 let a doctor take samples of suspicious areas like bronchoscopy does. Still, it may be a useful tool in some situations, such as in people who might be too sick to get a standard bronchoscopy.
This test will probably become more available as the technology improves.
Real-time tumor imaging
Researchers are looking to use new imaging techniques, such as four-dimensional computed tomography (4DCT), to help improve treatment. In this technique, the CT machine scans the chest continuously for about 30 seconds. It shows where the tumor is in relation to other structures as a person breathes, as opposed to just giving a ‘snapshot’ of a point in time, like a standard CT does.
4DCT can be used to determine exactly where the tumor is during each part of the breathing cycle, which can help doctors deliver radiation to a tumor more precisely. This technique might also be used to help show if a tumor is attached to or invading important structures in the chest, which could help doctors determine if a patient might be eligible for surgery.
Many clinical trials are looking at newer combinations of chemotherapy drugs to determine which are the safest and most effective. This is especially important in patients who are older and have other health problems. Doctors are also searching for better ways to combine chemotherapy with radiation therapy and other treatments.
Researchers are learning more about the inner workings of lung cancer cells that control their growth and spread. This is being used to develop new targeted therapies. These drugs work differently from standard chemotherapy drugs. They might work in some cases when standard chemo drugs don’t, and they often have different (and less severe) side effects. Many of these treatments are being tested in clinical trials to see if they can help people with lung cancer live longer or relieve their symptoms.
Anti-angiogenesis drugs: For cancers to grow, new blood vessels must develop to nourish the cancer cells within tumors. This process is called angiogenesis. New drugs that inhibit angiogenesis are being studied as lung cancer treatments.
Some are used for other cancer types. For example, a drug called bevacizumab (Avastin) has been shown to help patients with some types of non-small cell lung cancer. In studies of small cell lung cancer, it has helped stop some of the cancers from growing for a time, but so far it hasn’t been shown to help patients live longer.
Other drugs that affect blood vessel growth, such as sunitinib (Sutent) and nintedanib (BIBF 1120), are also being tested for use against SCLC.
Researchers are hoping to develop drugs that can help the body’s immune system fight the cancer.
Ipilimumab (Yervoy): This drug targets CTLA-4, a protein in the body that normally suppresses the immune response. Blocking this protein might help the immune system attack cancer cells. The drug is already used to treat melanoma, and it is now being studied in other cancers, including SCLC.
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. These types of treatments seem to have very limited side effects, so they might be useful in people who can’t tolerate other treatments. At this time, vaccines are only available in clinical trials.
Immune check point inhibitors: These are a promising class of new agents that are being studied for the treatment of lung cancer. In SCLC, the development of these compounds has just started recently.
Last Medical Review: 09/12/2014
Last Revised: 11/10/2014