Adenocarcinoma Gastric

Adenocarcinoma gastric is the most common form of stomach cancer, accounting for 90% to 95% of all stomach cancers. It develops in the cells that line the innermost layer of the stomach and often goes unnoticed in early stages, making it one of the leading causes of cancer death worldwide.

Table of contents

• What is adenocarcinoma gastric
• Types and classification
• Causes and risk factors
• Symptoms
• Diagnosis
• Stages of the disease
• Treatment options
• Nutrition and eating challenges
• Living with gastric adenocarcinoma

What is adenocarcinoma gastric

Adenocarcinoma gastric, also called gastric cancer or stomach cancer, is a type of cancer that starts in the cells lining the stomach. The stomach is an organ on the left side of the upper abdomen that plays a key role in digesting food. After food enters the stomach from the esophagus, stomach muscles mix it with digestive juices before passing it along to the small intestine^[4].

According to the American Cancer Society, adenocarcinomas account for 90% to 95% of stomach cancers. These cancers develop in certain mutated gland cells that exist in the mucosa, or the stomach’s innermost lining. These gland cells normally produce mucus and digestive juices^[3][7].

Stomach cancer is the fifth most common cancer worldwide and the fourth leading cause of cancer-related death globally, with nearly one million new cases diagnosed each year. In the United States, however, it is much less common, representing only about 1.5% of new cancer diagnoses annually^[3][13].

• Stomach
• Gastroesophageal junction
• Esophagus
• Small intestine

Types and classification

Adenocarcinoma of the stomach is divided into different types based on where it forms in the stomach and how the cells look under a microscope^[4].

Gastric cardia cancer begins in the top inch of the stomach, just below where it meets the esophagus. Non-cardia gastric cancer is cancer that begins in all other sections of the stomach. In the United States, most stomach cancers occur at the gastroesophageal junction, where the esophagus meets the stomach^[1][4].

Adenocarcinoma of the stomach may also be described as intestinal or diffuse, depending on how the cells look under a microscope. Intestinal adenocarcinomas are well differentiated, meaning the cancer cells look similar to normal cells. Diffuse adenocarcinomas are undifferentiated or poorly differentiated, meaning the cancer cells look very different from normal cells. Diffuse adenocarcinomas tend to grow and spread more quickly than the intestinal type and are harder to treat^[4].

A rare type of adenocarcinoma is called linitis plastica. This type spreads to the muscles of the stomach wall and makes it thicker and more rigid, so the stomach can’t hold as much food and doesn’t stretch or move properly during digestion. This stiff-walled stomach is sometimes called a leather bottle stomach. This type of cancer is very fast growing and is often at an advanced stage at diagnosis, which means surgery is usually not possible^[7].

Causes and risk factors

Like all cancers, adenocarcinomas develop when genetic mutations cause cells to grow in an uncontrolled way. Sometimes, a person inherits these cancer-causing genetic mutations from a biological parent. Infections can also cause adenocarcinoma^[3].

Scientists estimate that Helicobacter pylori (H. pylori) infections cause between 46% and 63% of stomach cancers. H. pylori is an infectious bacterium that affects the stomach’s inner lining. Long-term H. pylori infections cause inflammation of this lining, which can lead to adenocarcinoma. Infections from the Epstein-Barr virus may cause between 5% and 10% of adenocarcinomas^[3].

Several risk factors can increase your chances of developing stomach cancer. Nutritional factors include high salt intake, low vitamin A and C consumption, high intake of smoked or cured foods, drinking contaminated water, and high caloric intake. Exposure to tobacco smoke, radiation, and certain industrial substances like rubber, metal, and coal also increases risk^[3].

Additional risk factors include advanced age (most people diagnosed are 65 or older), being male, having chronic conditions like gastroesophageal reflux disease (GERD) or gastritis, having stomach ulcers or polyps, and obesity. Family history of stomach cancer and certain genetic conditions also play a role^[1][6].

Symptoms

Early stage adenocarcinomas typically do not cause symptoms. This is one reason why stomach cancer is often not discovered until later stages. When symptoms do occur, they can include^[3][17]:

• Low appetite
• Unintentional weight loss
• Abdominal pain or discomfort
• Feeling full quickly after eating small amounts
• Heartburn
• Indigestion
• Nausea
• Vomiting
• Abdominal swelling
• Bloody vomit or stool
• Tiredness or weakness

If the cancer has spread to the liver, jaundice (yellowing of the skin and eyes) may occur^[3].

Many of these symptoms are common in other conditions as well. If you experience any of these symptoms, especially if they persist, it’s important to see a healthcare provider for proper evaluation.

Diagnosis

To diagnose adenocarcinoma of the stomach, doctors may order several tests. The process typically begins with a medical history review and a physical exam focusing on the abdomen^[3].

Upper endoscopy is a key diagnostic procedure. During this test, a doctor places a thin, camera-mounted tube into the stomach through the esophagus. This allows them to view the inside of the stomach and look for abnormal areas^[3].

If unusual-looking tissue is found during endoscopy, the doctor will perform a biopsy, removing a small sample of tissue to examine under a microscope. This is the only way to confirm a cancer diagnosis^[3].

Imaging tests help determine the extent of the cancer. These may include CT scans (computed tomography), PET scans (positron emission tomography), and MRI scans (magnetic resonance imaging). These tests create detailed pictures of the inside of your body and can show whether cancer has spread to other areas^[3].

Blood tests may also be ordered to check overall health and determine if a patient is eligible for surgical treatment^[3].

Stages of the disease

The staging system for adenocarcinoma is complex. Understanding the stage of cancer helps doctors determine the best treatment approach^[3].

Stage 0 means there are either atypical-looking cells in the stomach lining or cancer cells only in the mucosa^[3].

Stage 1 means the cancer has grown from the mucosa into deeper layers of the stomach wall but hasn’t spread far^[3].

Stages 2 and 3 indicate the cancer has grown deeper into the stomach wall and may have spread to nearby lymph nodes^[12].

Stage 4 means the cancer has spread to distant parts of the body, such as the liver, lungs, or distant lymph nodes. This is also called metastatic cancer^[12].

The prognosis of patients with gastric cancer is related to how far the tumor has spread, including whether it has involved lymph nodes or extended beyond the gastric wall. When stomach cancer is found and treated early, more than 50% of patients with localized disease can be cured. However, early-stage disease accounts for only 10% to 20% of cases diagnosed in the United States^[14].

Treatment options

Treatment for adenocarcinoma gastric depends on where the cancer started, how far it has spread, your overall health, and your personal preferences. Many patients receive more than one type of treatment^[11].

Surgery is the main treatment for stomach cancer when possible. The type of surgery depends on where the cancer is located. Subtotal gastrectomy is the removal of the part of the stomach that contains cancer, along with nearby lymph nodes and parts of other nearby tissues. Total gastrectomy is the removal of the entire stomach, nearby lymph nodes, and parts of the esophagus, small intestine, and other tissues near the tumor. When the entire stomach is removed, the surgeon attaches the esophagus directly to the small intestine so the patient can continue to eat and swallow^[11].

For very early-stage cancer, endoscopic mucosal resection may be possible. This procedure uses an endoscope to remove cancer from the lining of the digestive tract without major surgery^[11].

Chemotherapy uses drugs to kill cancer cells or stop them from growing. It may be given before surgery to shrink the tumor, making it easier to remove. This is called neoadjuvant therapy. Chemotherapy given after surgery to kill any remaining cancer cells is called adjuvant therapy. For advanced stomach cancer, chemotherapy can help control the disease and improve quality of life^[11][13].

Radiation therapy uses high-energy rays to kill cancer cells. It is sometimes used along with chemotherapy, especially after surgery or when the cancer cannot be completely removed^[11].

Targeted therapy uses drugs that attack specific features of cancer cells. For stomach cancer, these include trastuzumab and trastuzumab deruxtecan, which target cancers with high levels of a protein called HER2. Another targeted drug, ramucirumab, works by blocking blood vessel growth to tumors^[11][13].

Immunotherapy helps your own immune system fight cancer. Drugs like pembrolizumab, nivolumab, and dostarlimab are checkpoint inhibitors that have been approved for certain types of stomach cancer. They work best in cancers that have specific markers, such as high levels of PD-L1 or DNA mismatch repair deficiency^[11][13][16].

The treatment landscape for gastric cancer has evolved significantly in recent years, with new immunotherapy and targeted therapies becoming available. Classification based on molecular biomarkers provides opportunities to identify patients who may benefit from these newer treatments^[13][15].

Nutrition and eating challenges

Stomach cancer and its treatments can cause significant problems with eating and digesting food. These problems may be caused by the cancer itself, by the removal of all or part of the stomach, or by side effects of treatments like chemotherapy^[19][22].

Weight loss is a very common problem for people with stomach cancer. A stomach tumor can cause blockages so food can’t pass normally. When cancer is advanced, the body’s ability to use energy from food changes, and energy is burned at a faster rate. After stomach surgery, you may not be able to eat large meals and may feel full after eating small amounts of food^[22].

To maintain your weight, try not to skip meals and eat regularly, even if it’s only a few bites. Choose foods and drinks that are high in protein and calories. Add whole milk or cream to cereals or soups, use sauces and gravies, or add extra butter to potatoes. Keep nutritious, high-calorie snacks readily available^[22].

Dumping syndrome can occur after part or all of the stomach is removed. This happens when food moves too quickly from the stomach into the small intestine. Symptoms include nausea, diarrhea, stomach cramps, bloating, feeling faint, and sweating. To reduce dumping syndrome, eat slowly and rest after eating. Reduce sugary foods, increase fiber intake, and eat smaller meals more frequently. Avoid very liquid foods and soups^[26].

Other eating problems can include diarrhea, feeling bloated, indigestion, and morning sickness. A registered dietitian can provide valuable guidance about proper nutrition tailored to your specific needs and help you manage side effects^[22][24].

Living with gastric adenocarcinoma

Living with advanced stomach cancer brings unique challenges that affect your physical, mental, and emotional health. Your relationships with food, physical fitness, social interactions, and future planning may all need modification^[23].

You will need increased medical attention throughout your treatment. Most people receive a combination of chemotherapy and surgery. Chemotherapy typically happens every two weeks, and appointments are usually needed once every other week. Progress is measured by looking at scans done every two to three months. Working with palliative medicine specialists can help with pain management and strategies for staying comfortable^[23].

Advanced care planning is critical. In the days after receiving a diagnosis, it’s important to talk with your family or loved ones about what matters most to you. Consider discussing advance directives, which are legal documents that determine what your healthcare providers should do in emergencies. A living will tells providers what medical care you do and don’t want. A durable power of attorney designates someone who can make medical decisions for you if you’re unable to do so^[23].

Emotional support is important throughout your journey. Speaking up about any problems or concerns gives you a greater sense of control. Your healthcare team can talk with you about ways to reduce side effects and help you feel better. Many resources are available to help you cope with the emotional side effects of cancer^[19][20].

After treatment, you will need regular follow-up care. Your doctor will schedule routine exams and tests to check for any signs that cancer has returned. This ongoing monitoring is an important part of survivorship care^[21].