Gastric cancer is the third most common cause of cancer-related death in the world, and it remains difficult to cure in Western countries, primarily because most patients present with advanced disease. In the United States, stomach malignancy is currently the 15th most common cancer. The stomach begins at the gastroesophageal junction and ends at the duodenum. Almost all gastric cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids). Other types of gastric cancer are gastrointestinal carcinoid tumors, gastrointestinal stromal tumors, and lymphomas. Stomach cancer is uncommon in the United States, and the number of people diagnosed with the disease each year is declining. Stomach cancer is much more common in other areas of the world
Infection with bacteria called H. pylori is a common cause of gastric cancer.
Gastric cancer is often diagnosed at an advanced stage because there are no early signs or symptoms.
Signs and symptoms
Early gastric cancer has no associated symptoms; however, some patients with incidental complaints are diagnosed with early gastric cancer. Most symptoms of gastric cancer reflect advanced disease. All physical signs in gastric cancer are late events. By the time they develop, the disease is almost invariably too far advanced for curative procedures.
Signs and symptoms of gastric cancer include the following:
- Feeling bloated after eating
- Feeling full after eating small amounts of food
- Heartburn that is severe and persistent
- Indigestion that is severe and unrelenting
- Nausea that is persistent and unexplained
- Stomach pain
- Vomiting that is persistent
- Weight loss that is unintentional
- Loss of appetite
- Melena or pallor from anemia
- Palpable enlarged stomach with succussion splash
- Enlarged lymph nodes such as Virchow nodes (i.e., left supraclavicular) and Irish node (anterior axillary)
- Late complications of gastric cancer may include the following features:
- Pathologic peritoneal and pleural effusions
- Obstruction of the gastric outlet, gastroesophageal junction, or small bowel
- Bleeding in the stomach from esophageal varices or at the anastomosis after surgery
- Intrahepatic jaundice caused by hepatomegaly
- Extrahepatic jaundice
- Inanition from starvation or cachexia of tumor origin
It is not clear what causes stomach cancer. There is a strong correlation between a diet high in smoked and salted foods and stomach cancer. As the use of refrigeration for preserving foods has increased around the world, the rates of stomach cancer have declined. H. Pylori is a WHO listed carcinogen and implicated in the development of stomach cancer and MALT (Mucosal Associated Lymphoid Tumor)
In general, cancer begins when an error (mutation) occurs in a cell’s DNA. The mutation causes the cell to grow and divide at a rapid rate and to continue living when a normal cell would die. The accumulating cancerous cells form a tumor that can invade nearby structures. And cancer cells can break off from the tumor to spread throughout the body.
Factors that increase your risk of stomach cancer include:
- A diet high in salty and smoked foods
- A diet low in fruits and vegetables
- Eating foods contaminated with aflatoxin fungus
- Family history of stomach cancer
- Infection with Helicobacter pylori
- Long-term stomach inflammation
- Pernicious anemia
- Stomach polyps
The goal of obtaining laboratory studies is to assist in determining optimal therapy. Potentially useful tests in patients with suspected gastric cancer include the following:
- CBC: May be helpful to identify anemia, which may be caused by bleeding, liver dysfunction, or poor nutrition; approximately 30% of patients have anemia
- Electrolyte panels
- Liver function tests
- Tumor markers such as CEA and CA 19-9: Elevated CEA in 45-50% of cases; elevated CA 19-9 in about 20% of cases
Types of stomach cancer
The cells that form the tumor determine the type of stomach cancer. The type of cells in your stomach cancer helps determine your treatment options. Types of stomach cancer include:
- Cancer that begins in the glandular cells (adenocarcinoma).The glandular cells that line the inside of the stomach secrete a protective layer of mucus to shield the lining of the stomach from the acidic digestive juices. Adenocarcinoma accounts for the great majority of all stomach cancers.
- Cancer that begins in immune system cells (lymphoma).The walls of the stomach contain a small number of immune system cells that can develop cancer. Lymphoma in the stomach is rare.
- Cancer that begins in hormone-producing cells (carcinoid cancer).Hormone-producing cells can develop carcinoid cancer. Carcinoid cancer in the stomach is rare.
- Cancer that begins in nervous system tissues.A gastrointestinal stromal tumor (GIST) begins in specific nervous system cells found in your stomach. GIST is a rare form of stomach cancer.
Imaging studies that aid in the diagnosis of gastric cancer in patients in whom the disease is suggested clinically include the following:
- Esophagogastroduodenoscopy (EGD): To evaluate gastric wall and lymph node involvement
- Double-contrast upper GI series and barium swallows: May be helpful in delineating the extent of disease when obstructive symptoms are present or when bulky proximal tumors prevent passage of the endoscope to examine the stomach distal to an obstruction
- Chest radiography: To evaluate for metastatic lesions
- CT scanning or MRI of the chest, abdomen, and pelvis: To assess the local disease process and evaluate potential areas of spread
- Endoscopic ultrasonography (EUS): Staging tool for more precise preoperative assessment of the tumor stage
Biopsy of any ulcerated lesion should include at least six specimens taken from around the lesion because of variable malignant transformation. In selected cases, endoscopic ultrasonography may be helpful in assessing depth of penetration of the tumor or involvement of adjacent structures.
Histologically, the frequency of different gastric malignancies is as follows  :
- Adenocarcinoma – 90-95%
- Lymphomas – 1-5%
- Gastrointestinal stromal tumors (formerly classified as either leiomyomas or leiomyosarcomas) – 2%
- Carcinoids – 1%
- Adenoacanthomas – 1%
- Squamous cell carcinomas – 1%
See Workup for more detail.
Treatment and Management
The surgical approach in gastric cancer depends on the location, size, and locally invasive characteristics of the tumor.
Types of surgical intervention in gastric cancer include the following:
- Total gastrectomy, if required for negative margins
- Esophagogastrectomy for tumors of the cardia and gastroesophageal junction
- Subtotal gastrectomy for tumors of the distal stomach
- Lymph node dissection: Controversy exists regarding extent of dissection; the National Comprehensive Cancer Network (NCCN) recommends D2 dissections over D1 dissections; a pancreas- and spleen-preserving D2 lymphadenectomy provides greater staging information and may provide a survival benefit while avoiding its excess morbidity when possible 
Antineoplastic agents and combinations of agents used in managing gastric cancer include the following:
- Platinum-based combination chemotherapy: First-line regimens include epirubicin/cisplatin/5-FU or docetaxel/cisplatin/5-FU; other regimens include irinotecan and cisplatin; other combinations include oxaliplatin and irinotecan
- Trastuzumab in combination with cisplatin and capecitabine or 5-FU: For patients who have not received previous treatment for metastatic disease
- Ramucirumab for the treatment of advanced stomach cancer or gastroesophageal (GE) junction adenocarcinoma in patients with unresectable or metastatic disease following therapy with a fluoropyrimidine- or platinum-containing regimen
Neoadjuvant, adjuvant, and palliative therapies
Potentially useful therapies in gastric cancer include the following:
- Neoadjuvant chemotherapy
- Intraoperative radiotherapy (IORT)
- Adjuvant chemotherapy (eg, 5-FU)
- Adjuvant radiotherapy
- Adjuvant chemoradiotherapy
- Palliative radiotherapy
- Palliative-intent procedures (e.g., wide local excision, partial gastrectomy, total gastrectomy, simple laparotomy, gastrointestinal anastomosis, bypass)
Supportive (palliative) care
Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care. Palliative care can be used while undergoing other aggressive treatments, such as surgery, chemotherapy or radiation therapy.
When palliative care is used along with all of the other appropriate treatments, people with cancer may feel better and live longer.
Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.
By Srinivas Seela, MD
Srinivas Seela, MD moved to Orlando, Florida after finishing his fellowship in Gastroenterology at Yale University School of Medicine, one of the finest programs in the country. During his training he spent a significant amount of time in basic and clinical research, and has published articles in Gastroenterology literature.
His interests include advanced and therapeutic endoscopic procedures, colorectal cancer screening, Gastro Esophageal Reflux Disease (GERD), metabolic and other liver disorders.
Dr. Seela is board certified in both Internal Medicine and Gastroenterology. He is a member of the American Gastroenterological Association (AGA), the American Society for Gastrointestinal Endoscopy (ASGE), the American Association for the Study of Liver Diseases (AASLD), and Crohn’s Colitis Foundation (CCF).
In addition to being an Assistant Professor at the University of Central Florida School of Medicine, he is also a teaching attending physician at both the Florida Hospital Internal Medicine Residency and Family Practice Residence (MD and DO) programs. He is a regular contributing writer for Florida Md magazine. For an appointment with Dr. Seela, please call 407-384-7388.