Stomach Cancer

See Also:
Stomach Cancer: Overview
Stomach Cancer: Types
Stomach Cancer: Causes & Risk Factors
Stomach Cancer: Signs & Symptoms
Stomach Cancer: Stages
Stomach Cancer: Medical Tests & Diagnosis
Stomach Cancer: Treatment Options

ntroduction & Overview

Stomach cancer, also known as gastric cancer, is a form of cancer that develops in the lining and walls of the stomach. The cancer occurs when cancerous cells start to grow and divide abnormally resulting in tumors.

The stomach is a muscular, J-shaped organ located in the upper part of the abdomen. The stomach (also called gastrointestinal tract) is part of the digestive system where the food is deposited in order to be digested after being swallowed.

The stomach is divided in 3 main sections:

1. Cardia or proximal stomach: The upper part of the stomach located near the esophagus.
2. Fundus: This section of the stomach contains cells that produce acid and pepsin (a digestive enzyme) that digest food.
3. Distal stomach: The lower section of the stomach located near the small intestine.

The distal stomach is formed from two parts:
- Antrum: The area where food is mixed with the gastric fluids.
- Pylorus: A structure similar with a valve that controls the amount of food that passes into the small intestine.

The walls of the stomach are formed from four layers of tissue:

1.

Mucosa: The inner lining that contains glands which produce chemicals such as enzymes and acid which help digest food in the stomach.
2.

Submucosa: The layer of cells located directly beneath the inner lining (mucosa).
3.

Muscularis: The middle layer of tissue which moves and mixes the stomach content.
4.

Serosal: The outer layer of the stomach tissue which is a strong membrane that protects the stomach.

In most cases of stomach cancer, the tumors develop in the inner lining (mucosa) of the stomach and spread to the outer layer (serosal) as it grows. However, the location where the cancer starts varies from one case to another, causing different symptoms and outcomes. The location of the cancer plays a key role in determining the course of treatment.

Stomach cancer develops slowly and can span over many years before the first symptoms are recognized. The tissue or section of the stomach where the cancer develops undergoes a pre-cancerous stage before the actual cancer develops. During this pre-cancerous stage, the tissue suffers several modifications that if noticed in time can lead to a better treatment outcome. Unfortunately, these initial changes are not followed by symptoms and are difficult to detect.

Left untreated or diagnosed, stomach cancer grows and spreads to adjacent areas and organs. One way for the cancer to spread is through the lymph and blood vessels which form a complex rich network around the stomach. When it metastases, the stomach cancer spreads to the liver, lungs and bones. Once it spreads, the treatment plan becomes complicated and the outcome is not optimistic.