Gastric Cancer

Causes  |  Symptoms  |  Diagnosis  |  Types  |  Treatment  |  Outlook  |  Next Steps

Gastric cancer (also known as stomach cancer) is an abnormal growth of cells in the stomach. Although its exact causes are unknown, it can be effectively treated when it is diagnosed early enough. Common treatment options include surgical removal of the tumor, chemotherapy, radiation therapy, or a combination.

Key Facts

  • Gastric cancer is the sixth most common form of cancer and the third most fatal. Although a variety of treatment options exist when it is detected early, gastric cancer is often diagnosed at later stages in the U.S.
  • Symptoms of gastric cancer can be subtle, such as indigestion and difficulty swallowing. As the disease progresses, symptoms may progress to fatigue, bloody stools, nausea and vomiting, and unintentional weight loss.
  • Surgery is the most common form of treatment, while chemotherapy and radiation therapy is used for tumors too large to remove. In general, the earlier gastric cancer is detected, the more successful treatment will be.

Causes

Gastric cancer occurs when the DNA within a stomach cell undergoes a change, or mutation, that causes it to multiply and continue living long after normal cells would die. This produces an accumulation of cells called a tumor, which can invade other healthy cells and eventually spread, or metastasize, to other parts of the body.

Although the exact causes of these mutations are still not known, several risk factors can increase their likelihood:

  • Age and Gender: Gastric cancer is more common in men and is most commonly diagnosed in people over the age of 65.
  • Diet: Eating lots of highly preserved foods (such as smoked fish, salted meats, and pickled vegetables) has been shown to increase the risk of developing gastric cancer.
  • Ethnicity: Gastric cancer is a disease of racial disparity. Koreans and Korean Americans are at highest risk among those living in the United States, followed by African American, Hispanic American, and other Asian Americans.
  • Family History: A family history of gastric cancer, breast cancer, and cancer syndromes, such as hereditary nonpolyposis colorectal cancer (HNPCC) and Li Fraumeni Syndrome, can all increase the risk.
  • Gastroesophageal Reflux Disease (GERD): Left untreated, GERD can damage the lining of the stomach and esophagus and increase the risk of cancer.
  • Helicobacter Pylori Bacteria: Left untreated, infection with this kind of bacteria can lead to chronic inflammation of the inner layer of the stomach. It may possibly lead to the development of precancerous lesions as well.
  • Previous Stomach Surgery: Removal of part of the stomach for ulcers or previous removal of stomach polyps can both increase gastric cancer risk.
  • Smoking and Alcohol Abuse: Both excessive alcohol and smoking have been shown to increase the risk of gastric cancer.
  • Weight: Obesity (defined as a body mass index of 30 or above) can increase the risk of developing gastric cancer.

As of 2021, the American Cancer Society estimates that gastric cancer accounts for 1.5 percent of all cancers in the United States. This breaks down to the following statistics:

  • About 26,560 new cases (16,160 in men and 10,400 in women)
  • About 11,180 deaths (6,740 men and 4,440 women)

Symptoms

Symptoms of early stage gastric cancers are usually vague and similar to those of minor stomach aches, indigestions, and infections. However, as the disease progresses, symptoms become more serious and persistent.

The following are some of the most common symptoms of gastric cancer:

  • Abdominal pain or discomfort
  • Bloody or dark stools
  • Constant fatigue
  • Difficulty swallowing
  • Fullness or bloating after eating small amounts of food
  • Heartburn, indigestion
  • Loss of appetite
  • Nausea and vomiting
  • Unintentional weight loss

Diagnosis

The following methods may be used to diagnose gastric cancer:

  • Blood Chemistry Studies: These analyze a small sample of blood for signs of cancer in both the stomach and in tissue and organs throughout the body. An unusual amount of certain substances may be a sign of cancer.
  • Imaging Tests: These are used to take detailed images of the stomach and any surrounding organs, such as the esophagus, in order to look for signs of cancer. They may include computed tomography (CT) scans, endoscopic ultrasound (EUS), or a special type of X-ray called a barium swallow, which involves looking at your digestive tract as a liquid moves down it .
  • Upper Endoscopy: This procedure involves inserting a thin tube containing a tiny camera down the esophagus and into the stomach. A doctor or medical specialist will then visually inspect the stomach for signs of cancer.
  • Biopsy: This involves removing a small sample of cells from the stomach with a thin needle, then viewing them under a microscope for signs of cancer. This procedure is typically done only if anything suspicious is found during an endoscopy.

Types of Stomach Cancers

Diagnosis will determine the type and spread of the cancer. The vast majority (90 to 95 percent) of patients will develop a type of gastric cancer called adenocarcinomas, which develop from gland cells located on the inner lining of the stomach wall. There are three types of adenocarcinomas:

  • Proximal (Cardia): Affects the first part of the stomach and may extend into the gastroesophageal junction, where the stomach and esophagus meet. Risk factors for this type of cancer include obesity and gastroesophageal reflux disease (GERD).
  • Non-cardia: Affects any other part of the stomach. May develop from prolonged periods of inflammation and irritation. Commonly associated with chronic infection with Helicobacter pylori bacteria.
  • Diffuse: Grows within the stomach wall as scattered cells without forming a distinct tumor. May have a genetic cause.

Other forms of gastric cancer include the following:

  • Gastrointestinal Stromal Tumors (GISTS): Abnormal growth of specialized cells in the stomach and intestinal walls called interstitial cells of Cajal (ICCs).
  • Lymphomas: Abnormal growth of immune cells called lymphocytes. While this form of cancer can begin anywhere, it can sometimes begin in the stomach walls.
  • Carcinoid Tumors: Abnormal growth of hormone-producing (endocrine) cells in the stomach.

Treatment

The most common forms of treatment for gastric cancer are surgery, chemotherapy, and radiation therapy. Other treatment options may include immunotherapy, hormonal therapy, and targeted therapy. Which treatment option is best will depend on several factors, such as the cancer’s stage, the patient’s age, and their general health.

Surgery

Surgery remains the primary treatment option for the majority of patients with gastric cancer. There are several types of surgery depending on the size and extent of the cancer.

  • Endoscopic Resection: This is used for very small and early-stage cancers that have not spread beyond the stomach lining. Using a thin tube called an endoscope that is inserted down the esophagus and into the stomach, special tools cut away any cancerous areas. The two types of endoscopic resection procedures are endoscopic mucosal resection (EMR) and endoscopic submucosal resection (ESR).
  • Subtotal Gastrectomy (also called Partial Gastrectomy): This procedure removes just the part of the stomach that contains cancer, as well as nearby lymph nodes and any other tissues or organs affected by cancer. The spleen, an organ that works primarily as a blood filter, may also be removed.
  • Total Gastrectomy: This procedure removes the entire stomach, nearby lymph nodes, and possible parts of the esophagus and any other affected tissues and organs. The spleen may also be removed. Afterward, the esophagus is connected directly to the small intestine so that digestion can continue.

In many cases, surgery to treat gastric cancer can be performed using minimally invasive laparoscopic approaches and robotic assistance.

Chemotherapy

Chemotherapy is a type of treatment that uses drugs to kill or stop the growth of cancer cells. It can be given before surgery in order to shrink the tumor and make it easier to remove, or after surgery in order to remove any remaining cancer cells. If the tumor is small enough, chemotherapy can also be used by itself. However, it is typically given in conjunction with either surgery or radiation therapy.

There are several types of chemotherapy:

  • Systemic Chemotherapy: This involves either taking chemotherapy drugs by mouth or injecting chemotherapy drugs into a vein or muscle so that they can reach cancer cells throughout the body.
  • Regional Chemotherapy: This involves placing chemotherapy drugs directly into an organ or body cavity so that they affect only the cells in that specific region.
  • Intraperitoneal (IP) Chemotherapy: This is a type of regional chemotherapy often used to treat gastric cancer that places the drugs in the peritoneal cavity, which contains the abdominal organs.

Radiation Therapy

Radiation therapy uses high-energy beams of X-rays or photons to kill cancer cells or stop them from growing. This treatment uses a machine to send radiation to the specific area of the body containing cancer. Similar to chemotherapy, this treatment can be used either before surgery in order to shrink the tumor, or after surgery to eliminate any remaining cancer cells.

Immunotherapy

Immunotherapy uses the body’s own immune system to attack and destroy cancer cells. Because cancer cells can inhibit the immune system by producing proteins that prevent it from recognizing them as dangerous, immunotherapy interferes with this process. This type of treatment is typically used when the cancer is in advanced stages.

Targeted Drug Therapy

Targeted drug therapy relies on identifying specific weaknesses in cancer cells, then administering drugs that exploit those weaknesses. This helps attack and kill cancer cells while causing less harm to healthy cells than chemotherapy or radiation therapy. Monoclonal antibodies are one prominent form of targeted drug therapy often used with gastric cancer. This type of treatment is typically combined with chemotherapy.

Screening & Prevention

Beyond the standard procedures for diagnosing gastric cancer, there is currently no process in place for proactively screening for it. Instead, patients should try to pay close attention to any possible symptoms of gastric cancer, especially if they persist for a long time.

Patients with one or more risk factors may want to consult with their doctor and take additional preventative steps to avoiding gastric cancer, such as:

  • Quitting smoking
  • Treating chronic Helicobacter pylori infections
  • Eating plenty of fresh fruits and vegetables
  • Avoiding salt and smoked meats
  • Taking vitamins, minerals, and other dietary supplements

More clinical trials are currently under way to find new ways of preventing gastric cancer.

Outlook

The outlook for gastric cancer depends heavily on its stage and extent at diagnosis. While early-stage gastric cancer is highly treatable, later-stage gastric cancer is associated with a lower survival rate.

The National Cancer Institute (NCI) divides gastric cancer survival rates into three distinct groups: localized (cancer that has not spread beyond the stomach), regional (cancer that has spread to nearby lymph nodes), and distant (cancer that has spread to other organs). The following is the five-year survival rate for gastric-cancer patients in each group:

  • Localized: 70 percent
  • Regional: 32 percent
  • Distant: 6 percent

The overall survival rate for gastric cancer is 32 percent.

Next Steps

We understand how frightening a gastric cancer diagnosis can be. That’s why our Gastric Cancer Care Program is committed to providing you with comprehensive treatment options and expert, quality care at every step. Our experienced team will work closely with you to build out a multidisciplinary approach to remove your tumor and eliminate any remaining cancer cells. To do this, we offer specialized services, such as robotic surgical options, not offered anywhere else, while our extensive postoperative and preventative care services will help you recover quickly and remain cancer free.

To make an appointment, call (212) 305-0273 or request an appointment online.

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