Stomach Cancer: Causes, Prevention and Treatment

Gastrointestinal (GI) cancers are among the most widespread cancers in the world. The most common GI cancers include colorectal, liver (hepatocellular), esophageal, pancreatic and stomach cancer. Among the less common GI cancers are small bowel cancer, cholangiocarcinoma, gall bladder cancer, anal cancer and neuroendocrine cancers.  

In the United States, Stomach cancer may not be quite as common as other GI cancers, but globally, stomach cancer is quite common, with over 600,000 new cases of stomach (gastric) cancer diagnosed annually. In presenting the following information, we have an opportunity to focus on a disease that is far from rare but receives less public attention than other, more familiar types of cancer.  

For answers to your FAQs, see the following exchange with Dr. Manish Shah, who serves as Bartlett Family Professor in Gastrointestinal Oncology, Professor of Medicine and Attending Physician at Weill Cornell Medicine.  

Have new cases of stomach cancer been increasing? 

In the United States, cases of stomach cancer have actually fallen over the past 100 years, Dr. Shah says, largely because of technological improvements. “For example, since the 1930s, when refrigeration became common in the U.S., there has been less reliance on salted meats and canned foods, which are associated with increased stomach cancer risk. As well, we now treat H. Pylori infection—an environmental bacteria associated with chronic inflammation and stomach cancer—with antibiotics. 

“However,” he adds, “cancers of the gastroesophageal junction (the area between the esophagus and stomach) have increased dramatically over the past 30 years or so. It's more common in men than women and seems to be associated with stress, along with gastroesophageal reflux disease and obesity.” 

What are the main drivers of stomach cancer? 

Microbes  

H. Pylori and the Epstein Barr virus, for example, are associated with stomach cancer.  

Inflammation 

Inflammation in the form of chronic gastritis can lead to stomach cancer. Eating plenty of fruits and vegetables can reduce the risk.    

Genetics 

Certain genetic syndromes are associated with a higher risk of stomach cancer as well. The most common is Lynch Syndrome, caused by the loss of a critically important repair protein. Mutations in the CDH1 gene have been linked to another type of stomach cancer: hereditary diffuse gastric cancer. 

What are the symptoms of stomach cancer? 

The usual symptoms of stomach cancer include abdominal pain, early satiety—a feeling of fullness earlier than expected during a meal—and weight loss. People usually have symptoms for 6 to 9 months before they’re diagnosed.  

“We usually diagnose the disease via endoscopy combined with tissue biopsy,” says Dr. Shah. 

What are the treatment options for patients with stomach cancer? 

For patients with disease that’s limited to the stomach, treatment usually consists of a combination of chemotherapy and surgery. The goal is to eradicate the disease and hope for a cure. However, patients whose cancers have spread beyond the stomach have advanced disease. For most of these patients, Dr. Shah says, “we can use chemotherapy to improve survival, but only in a few patients can we eradicate the disease altogether.”  

But that grim picture has recently become brighter. For patients with advanced disease, there has been a revolution in the treatment of stomach cancer. “It’s called targeted therapy, meaning treatment is tailored to changes in the tumor, making it more effective and, often, with fewer side effects,” he says. 

Now, most patients with stomach cancer will be treated with chemotherapy plus a targeted drug. For example, if you overexpress a protein called PD-L1, you’ll receive immunotherapy with chemotherapy, and if you also overexpress another protein called HER2, we’ll add the monoclonal antibody trastuzumab, he explains.   

“We recently discovered a new target, called Claudin18.2—a protein that sits on the surface of the cell membranes in stomach tissue. But as the tissue becomes cancerous, these surface proteins become exposed. Zolbetuximab, another targeted drug, is able to bind to these newly exposed proteins and activate an anti-cancer immune response. 

“In the GLOW study, a clinical trial that we conducted at Weill Cornell, we showed that the addition of zolbetuximab to chemotherapy in CLDN18.2-positive patients was associated with an increase in survival of 25 percent compared with chemotherapy alone. Our data led to the recent approval of this new targeted therapy for stomach cancer.”  

How do you and your team of specialists manage the side effects of chemotherapy? 

Side effects can usually be well managed with anti-nausea medications and medications for diarrhea, if needed. “Sometimes, in the case of immunotherapy, where the side effect is caused by overactivation of the immune system, we balance the immune response by administering immunosuppressive therapy—steroids, for instance,” he says. 

What other types of patient support does your team provide?

At Weill Cornell Medicine, there’s a large team of people behind every patient. In addition to the treating physician, “our practice physician assistants and chemotherapy nurses are important sources of support, Dr. Shah says. “Additional support is provided by our gastroenterology group, radiation oncologists and surgeons, each of whom addresses different aspects of the disease. We also have social workers, patient navigators and dietitians.” 

Like many other types of GI cancer, he says, stomach cancer is en route to becoming a manageable disease, thanks to ongoing research into new targets and treatments. That may not happen as quickly as we’d like, he says, but we’ll get there. 

To consult with a stomach cancer specialist, please visit here or call (646) 962-6200 for an appointment.