What’s New in Small Cell Lung Cancer Research?
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 most lung cancer deaths. Research is continuing on:
- Ways to help people quit smoking and stay tobacco-free 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 help prevent lung cancer in people at high risk, but so far none have been shown clearly 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 smaller than the increased risk from smoking, following the American Cancer Society dietary recommendations (such as staying at 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?, screening with spiral CT scans in people at high risk of lung cancer (due to smoking history) has been found to lower the risk of death from lung cancer, when compared to chest x-rays.
Another approach now being studied uses newer, sensitive tests to look for cancer cells in sputum samples. Researchers have found several changes often seen in the DNA of lung cancer cells. Studies are looking at 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 might help doctors find some lung cancers earlier, when they are likely to 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 can 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 a chest CT scan to create a detailed 3-dimensional picture 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 they might not be able to reach with standard bronchoscopy, such as those being blocked by a tumor. But this test 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.
Several newer methods for giving radiation therapy have become available in recent years, For example, some newer radiation therapy machines have imaging scanners built into them. This advance, known as image guided radiation therapy (IGRT), lets the doctor take pictures of the lung and make minor adjustments in aiming just before giving the radiation. This may help deliver the radiation more precisely, which might result in fewer side effects.
Clinical trials are looking at newer chemotherapy drugs and combinations of 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.
Targeted therapy drugs
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 therapy drugs. 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.
Some of the targeted drugs now being studied include alisertib and linsitinib.
Researchers are developing immunotherapy drugs that can help the body’s immune system fight the cancer.
Immune check point inhibitors: Cancer cells can sometimes avoid being attacked by the body’s immune system by using certain “checkpoints” that normally keep the immune system in check. For example, cancer cells often have a lot of a protein called PD-L1 on their surface that helps them evade the immune system. New drugs that block the PD-L1 protein, or the corresponding PD-1 protein on immune cells called T cells, can help the immune system recognize the cancer cells and attack them.
Nivolumab (Opdivo) and pembrolizumab (Keytruda) are anti-PD-1 drugs that are already used to treat advanced non-small cell lung cancer. These drugs have also been shown to shrink some small cell lung cancers in early studies.
Ipilimumab (Yervoy) is a drug that targets CTLA-4, another protein in the body that normally suppresses the immune response. The drug is also being studied in SCLC.
The combination of CTLA-4 and PD-1 targeted drugs has also shown early promise in 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.
Last Medical Review: February 22, 2016 Last Revised: May 16, 2016