Stomach Cancer

Risk Factors

Most of the digestive process occurs in the stomach, and then the partly digested food is moved along to the colon, where important nutrients will be assimilated into the body. In the United States, stomach cancer ranks as the 14th most common cancer, and is most commonly found in East Asian countries such as Japan and China. This may be due to their diet consisting heavily of salty or pickled foods. Cases of stomach cancer are also common in Thailand. Research has shown that occurrence of stomach cancer is associated with Helicobacter pylori, a microaerophilic bacterium found in the stomach. It has the ability to cause stomach ulcers and chronic gastritis. People with H. pylori are at a much higher risk of stomach cancer. More than 90 % of stomach cancers are found between gland cells and the lining of the stomach wall. Cancers that are associated with the glands are referred to as adenocarcinoma. Another type of cancer that may occur due to abnormalities in the stomach are lymphoma and squamous cell carcinoma

Symptoms

Stomach cancer often does not display specific or obvious symptoms. Patients may feel pain in the upper abdominal area, lack of appetite, intermittent vomiting, burping, less intake of food. Symptoms of stomach cancer may be similar to symptoms of stomach ulcers or gastritis, as such accurate diagnosis becomes more difficult. Other symptoms may include vomiting up blood, trouble swallowing, weight loss without a clear cause, weakness, and passing black stools. Stomach cancer is often found once it has already spread as it was not diagnosed in the early stages due to its unclear symptoms and indicators.

Diagnosis

An endoscope is effective for diagnosis in 95% of cases to determine the presence and stage of stomach cancer. Newer methods include Ultrasound with EVS, which can provide more detail regarding whether or not the cancer has spread to lymph nodes or surrounding areas. Other diagnostic techniques include the use of X-ray and PET/CT scans which are also effective in determining if the cancer has spread to vital organs such as the liver or lungs.

Treatment

Surgical treatment includes Subtotal (partial) gastrectomy: With this approach only part of the stomach is removed, sometimes along with part of the esophagus or the first part of the small intestine. Nearby lymph nodes are also removed, sometimes along with other nearby organs. The other option is Total gastrectomy: In this operation, the surgeon removes all of the stomach. The nearby lymph nodes are removed, and sometimes also the spleen and parts of the esophagus, intestines, pancreas, and other nearby organs.

The main choice of treatment of stomach cancer in its early stages is surgery.

In patients where the cancer has spread, surgical treatment will often result in recurrence in 2 in 3 cases. The cancer may come back and spread to lymph nodes or vital organs.

Chemotherapy and radiotherapy are recommended for stomach cancer in B1 stage or higher (cancer has spread to wall linings or lymph nodes). A combination of chemotherapy and radiotherapy will result in higher chance of successful treatment.

The standard chemotherapy for stomach cancer includes the use of 5-FU in conjunction with leucovorin injection into the vein. Side effects may include nausea, diarrhea, changes in skin, and mouth ulcers. Other chemotherapy medications are being researched such as oxaloplatin and epirubicin. However 5-FU and leucovorin injections are the standard treatment for stomach cancer.

Author

Dr. Wutthi Sumetchotimaytha Surgical Oncologist