An abnormal finding during a stomach endoscopy, also known as an upper gastrointestinal endoscopy or esophagogastroduodenoscopy (EGD), is the start of a detailed diagnostic process, not an immediate cancer diagnosis. The procedure involves inserting a flexible tube equipped with a camera through the mouth to visualize the lining of the esophagus, stomach, and the first part of the small intestine (duodenum). An EGD is performed to investigate symptoms like unexplained pain, bleeding, or persistent nausea, providing a direct view of the upper digestive tract. When the physician notes something visually concerning, this initial assessment guides the next steps in clarifying whether the change is benign, pre-cancerous, or definitively malignant.
Interpreting Abnormal Visual Findings
The physician looks for irregularities in the color, texture, and contour of the stomach lining, which often appear as masses, ulcers, or areas of severe inflammation. Many non-cancerous conditions can create visual abnormalities that mimic malignant growths. For instance, severe inflammation, known as gastritis, can cause the stomach lining to look red, swollen, and irregular.
Gastric polyps are common findings, representing growths that project from the stomach wall, and they are frequently benign. Peptic ulcers, which are open sores, can also appear irregular and crater-like, sometimes developing raised borders that are visually indistinguishable from an ulcerated tumor.
Adenomatous polyps are considered pre-cancerous and carry a higher risk of turning malignant, especially if they are large or display high-grade cellular changes. Areas of intestinal metaplasia, where the stomach lining cells are replaced by intestinal-like cells, can also look like abnormal patches. The visual features, such as a reddish surface color change or mucosal ulceration, are recognized as predictive factors for cancer, but the visual interpretation alone is insufficient to confirm a diagnosis.
The Definitive Diagnosis: Biopsy and Pathology
The only way to confirm or rule out cancer after an abnormal finding is through a biopsy, which involves using tiny forceps passed through the endoscope to collect small tissue samples. These samples are then sent to a pathologist who examines them under a microscope to determine the precise nature of the cells. The pathologist’s report provides the definitive diagnosis.
The pathology report uses specific terminology to classify the degree of cellular abnormality. Dysplasia describes pre-cancerous changes where the cells look abnormal but are confined to the inner lining (mucosa) without invading deeper tissue layers. Low-grade dysplasia suggests minor cellular changes that may regress, while high-grade dysplasia indicates significant abnormal cells that carry a high likelihood of progressing to cancer.
A diagnosis of carcinoma in situ (Tis) means cancer cells are present but remain strictly within the most superficial layer of the stomach lining. When the cells break through the basement membrane and infiltrate the underlying connective tissue, the diagnosis becomes invasive carcinoma. For challenging tumors, the pathologist may employ immunohistochemistry, a technique that uses specific antibodies to stain cellular proteins, helping to confirm the cell type and guide potential targeted treatment options.
Primary Types of Gastric Cancer
If the biopsy confirms a malignant process, identifying the specific type of cancer is necessary, as treatment strategies vary significantly based on cellular origin. Gastric adenocarcinoma is the most common form, accounting for approximately 90% to 95% of all stomach cancer cases. This type originates in the gland cells that form the innermost lining of the stomach wall (mucosa).
Adenocarcinoma Subtypes
Adenocarcinomas are broadly categorized into the intestinal type and the diffuse type. The intestinal type often develops from chronic inflammation, tends to be more localized, and generally has a better prognosis. The diffuse type is characterized by scattered, poorly cohesive cells that infiltrate the stomach wall, leading to a thickened, rigid stomach, and tends to spread more quickly.
Less Common Types
Less common types of gastric malignancy originate from different tissue components. Gastrointestinal Stromal Tumors (GISTs) arise from specialized cells called the interstitial cells of Cajal. Gastric lymphomas originate from immune system cells found in the stomach wall, and neuroendocrine tumors develop from hormone-producing cells.
Overview of Staging and Treatment Planning
Following a cancer diagnosis, the immediate priority is staging, a process that determines the extent of the cancer’s spread throughout the body. Staging is performed using various imaging tests, such as computed tomography (CT) scans, positron emission tomography (PET) scans, and endoscopic ultrasound (EUS). These tests help visualize the tumor’s size, depth of penetration, and whether it has spread to nearby lymph nodes or distant organs.
The standard staging system is the TNM system, which uses three components to classify the cancer: T for the size and depth of the primary Tumor, N for the presence of affected regional lymph Nodes, and M for distant Metastasis. The results from the TNM classification are combined to assign the cancer a stage, ranging from Stage 0 (carcinoma in situ) to Stage IV (distant metastasis).
Treatment for gastric cancer is determined by the cancer’s stage, type, and the patient’s overall health, requiring a multidisciplinary team of specialists. Treatment options include surgery to remove part or all of the stomach, chemotherapy, radiation therapy, and targeted therapy. For early-stage cancers, treatment may be curative, while advanced-stage cancers focus on controlling the disease and managing symptoms.