Overview
After swallowing, food enters esophagus and is then passed onto a sac-like organ in the upper abdomen called stomach. It holds food and starts to digest it by secreting gastric juice. The food and gastric juice are mixed and then emptied into the first part of the small intestine called the duodenum.
Stomach wall is made of five layers of tissue. Stomach cancer begins in the inner most layer, mucus-producing cells that line the stomach. It then advances and spreads.
Types
Risk factors for stomach cancer
While stomach cancer is relatively rare compared to other types of cancer, one of the biggest dangers of this disease is the difficulty of diagnosing it. Since stomach cancer usually doesn’t cause early symptoms, it often goes undiagnosed until after it spreads to other parts of the body. This makes it more difficult to treat.
Symptoms of stomach cancer are:
Diagnosis
Diagnosis of stomach cancer is established by doing an upper endoscopy. It is a procedure in which a flexible thin tube with camera is passed and stomach is seen from inside. If any abnormality is seen then a small sample from it is obtained called as biopsy and examined under microscope confirming the diagnosis.
Determining extent of disease
Depending upon the suspected extent of disease some of the following investigations will be done to determine the exact stage. In addition various lab tests will be done to assess function of various organs.
Following this work-up a stage will be assigned to the tumor, which spans from I to IV. It is based on three key elements.
The extent (size) of the tumor (T): How far has the cancer grown into the 5 layers of the stomach wall? Has the cancer reached nearby structures or organs?
The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes? And to how many?
Treatment
Treatment will depend upon stage of tumor and fitness of patient to undergo major surgical procedure. Treatment can be broadly categorised into curative and palliative.
Palliative treatment is designed to relieve symptoms, and improve quality of life. Palliative treatment is considered when tumor is too advanced or disseminated. A patient unfit for major surgery is also treated with palliative intent. Blockage can be treated by inserting stent (a hollow metal tube). Chemotherapy can provide symptomatic relief along with prolonging life. Sometimes surgery such as gastrojejunostomy or gastrectomy is also needed for symptoms or complications.
Curative treatment aims to eradicate the disease. To obtain best results for advanced tumors chemotherapy and/or radiotherapy and surgery are combined in an approach called multimodal treatment. Depending upon the extent of tumor, chemotherapy or chemoradiation can be given before surgery or after surgery.
Chemotherapy is use of special drugs to kill cancer cells. Radiotherapy is use of high-powered X-ray beams to kill cancer cells.
Stomach cancer that has not spread requires surgery to remove the part of the stomach where the tumor is located. The goal of surgery is to remove all of the cancer and a margin of healthy tissue, when possible. Omentum and nearby lymph nodes are removed as well.
Gastrectomy used to be done as an open procedure with large incisions. Now in selected patients this surgery can be performed with minimally invasive techniques in which special surgical tools are inserted through small holes commonly known as laparoscopic gastrectomy. This results in faster recovery and reduced pain compared to the conventional open surgery.
According to the American Cancer Society, the percentages of people who live for at least five years after being diagnosed with stomach cancer is 68-82% for stage II and 18-54% for stage III cancers.
