What’s new in stomach cancer research and treatment?
Research is always being done in the area of stomach cancer. In addition to looking for the causes and ways to prevent stomach cancer, scientists continue to look for better treatments.
Research has clearly shown that differences in diet are an important factor in explaining variations in stomach cancer risk around the world. Recent research in countries with relatively low stomach cancer risk has provided some insight into risk factors. Diets high in preserved meats and low in fresh fruits and vegetables have been linked with higher risk.
Helicobacter pylori infection
Recent studies have shown that certain types of H pylori (especially the cagA strains) are more strongly linked to stomach cancer. Some inherited traits related to blood groups may also affect whether someone infected with H pylori will develop cancer. Further research is needed to help doctors determine how to use this information to test which people might be at higher risk for developing stomach cancer.
Recent research has also studied the interaction of H pylori infection with other risk factors. For example, they have found that a healthy diet is especially important for reducing stomach cancer risk for people infected with H pylori.
Chemoprevention is the use of natural or man-made chemicals to lower the risk of developing cancer. Some types of chemicals might be useful in helping prevent stomach cancer.
Many carcinogenic (cancer-causing) factors cause cells to form a type of chemical called a free radical. Free radicals can damage important parts of cells such as genes. Depending on how severe the damage is, the cells may die or they may become cancerous.
Antioxidants are a group of nutrients and other chemicals that can destroy free radicals or prevent them from forming. These nutrients include vitamin C, beta-carotene, vitamin E, and the mineral selenium. Studies that have looked at using dietary supplements to lower stomach cancer risk have had mixed results so far. There is some evidence that combinations of antioxidant supplements may reduce the risk of stomach cancer in people with poor nutrition to begin with. Further research in this area is needed.
Studies are being done to see whether antibiotic treatment of people who are chronically infected by H pylori will help prevent stomach cancer. Some studies have found that treating this infection may prevent pre-cancerous stomach abnormalities, but more research is needed.
Although not truly chemoprevention, antibiotics may help prevent stomach cancer from recurring in some cases. Researchers have shown that antibiotics may lower the risk that the cancer will come back in another part of the stomach in people who have been treated with endoscopic mucosal resection for early stage stomach cancer. Unfortunately, in the United States stomach cancers are more often found at a later stage, so it’s not clear how useful these results might be here.
Non-steroidal anti-inflammatory drugs (including aspirin)
Some (but not all) studies have found that people who take non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen might have a lower risk of stomach cancer. More research is needed to better define this possible link. In the meantime, doctors generally don’t recommend taking these medicines just to try to lower your risk of cancer, as they can cause serious side effects in some people.
Sentinel lymph node mapping
Doctors are trying to identify the spread of stomach cancer to lymph nodes using this technique, which has proved very successful in melanoma and breast cancer.
In sentinel lymph node mapping, the surgeon injects a blue dye and/or a radioactive tracer substance into the cancer. These concentrate in the lymph nodes that would be the first site of cancer spread. Doctors can remove these lymph nodes and look for cancer. If no cancer is found in these lymph nodes, then the cancer is unlikely to have reached others, and a full lymph node removal might not be needed. If cancer is found in the sentinel lymph node(s), then all the lymph nodes would still need to be removed.
This technique has been shown to help find more lymph nodes to remove, and to find lymph nodes that are more likely to contain cancer cells. But this technique is still being studied in stomach cancer and is not yet ready for widespread use.
Laparoscopy is sometimes used to help stage (determine the extent of) stomach cancer. Doctors are now studying the use of laparoscopic (keyhole) surgery to remove small stomach cancers.
In this technique, the surgeon creates several small holes in the abdomen, each about an inch long. Special long, thin instruments are inserted into these holes. One of the instruments has a small video camera on the end. The others are used to cut, staple, or sew sections of the stomach. Often, the doctor maneuvers the instruments using robotic arms while sitting at a specially designed control panel inside the operating room. This is known as robotic-assisted laparoscopic surgery.
An advantage of this type of surgery is that it does not require a large incision in the abdomen, so recovery time is usually quicker. In one early study, laparoscopy seemed to be about as effective as standard surgery. Still, it is not widely used to treat stomach cancer in the United States, and more studies are needed to prove that it is as good as the standard approach.
Chemotherapy drugs and combinations
Some studies are testing new ways to combine drugs already known to be active against stomach cancer or other cancers. Newer chemotherapy (chemo) drugs are also being studied. For example, S-1 is an oral chemo drug related to 5-FU. This drug is commonly used for stomach cancer in some other parts of the world, but it is not yet available in the United States.
Other studies are testing the best ways to combine chemo with radiation therapy, targeted therapies, or immunotherapy. A good deal of effort is being directed at improving the results of surgery by adding chemo and/or radiation therapy either before or after surgery. Several clinical trials of this approach are in progress.
New ways of giving chemo are also being studied. For example, some doctors are looking at infusing chemo directly into the abdomen (intraperitoneal chemotherapy) to see if it might work better with fewer side effects.
Chemo drugs target cells that divide rapidly, which is why they work against cancer cells. But there are other aspects of cancer cells that make them different from normal cells. In recent years, researchers have developed new targeted drugs to try to exploit these differences. Targeted drugs sometimes work when standard chemo drugs don’t. They also tend to have less severe side effects than chemo drugs.
Drugs that block HER2: Some stomach cancers have too much of the HER2 protein on the surface of their cells, which helps them grow. Drugs that target this protein might help treat these cancers. Trastuzumab (Herceptin) is already approved for use against advanced stomach cancer. Other drugs that target HER2, such as lapatinib (Tykerb®), pertuzumab (Perjeta®), and trastuzumab emtansine (TDM-1) are now being studied in clinical trials.
Drugs that block EGFR: EGFR is another protein found on some stomach cancer cells that helps them grow. Drugs that block EGFR, such as cetuximab (Erbitux®) and panitumumab (Vectibix®) have shown some promise against stomach cancer in early studies and are now being tested in larger clinical trials. These drugs are already FDA-approved to treat some other cancers.
Other targeted drugs: Other drugs target different parts of cancer cells. Targeted drugs that are FDA-approved for other types of cancer and are now being studied against stomach cancer include everolimus (Afinitor®) and sorafenib (Nexavar®), among others.
Most of the research in this area is looking at combining targeted agents with chemotherapy or with each other.
Immunotherapy is an approach that uses drugs to try and help the body’s immune system fight the cancer.
A Korean study showed that combining chemotherapy with an immunotherapy called polyadenylic-polyuridylic acid (poly A:U) slowed stomach cancer from returning when given as adjuvant therapy after surgery. It also helped some patients live longer.
You can learn more about immunotherapy in our document Immunotherapy. You can read it online or call us for a free copy.
If you want to search for clinical trials in your area, contact the American Cancer Society at 1-800-227-2345 or visit us on the Web at www.cancer.org/clinicaltrials.
Last Medical Review: 02/15/2013
Last Revised: 02/22/2013