Stomach

Types of stomach cancer

Stomach cancer generally progresses slowly and may not show symptoms in its early stages. It is more common in men over 60 years old. When symptoms do appear, they typically include weight loss, loss of appetite, abdominal pain, and fatigue.

What is stomach cancer?

Stomach cancer, also known as gastric cancer, occurs due to abnormal growth of cells. This abnormal growth often develops slowly, over years.

Before cancer appears, precancerous changes can be seen in the mucosa, which is the inner lining of the stomach. These changes rarely cause symptoms and therefore often go unnoticed, making their diagnosis even more challenging.

Getting to Know the Primary Form of Stomach Cancer

Gastric cancer can affect any part of the stomach, although it is most commonly observed in a region called the body of the stomach. The histological type adenocarcinoma accounts for about 95% of cases of malignant stomach tumors.

Adenocarcinoma of the stomach primarily affects men around the age of 60-70. About 80% of patients are over 50 years old.

In Brazil, stomach cancer is the third most common type among males and the fifth among females. It is estimated that in 2020 there were 21,230 new cases, with 13,360 in men and 7,870 in women.

Other types of tumors (besides adenocarcinomas) can also occur in the stomach. Among these are MALT type lymphomas and gastrointestinal stromal tumors, better known as GISTs.

Types of stomach cancer

Adenocarcinomas can be divided into two subtypes: intestinal and diffuse. Learn more about them:

• Intestinal – the intestinal type commonly occurs in older patients, mostly males, and is associated with chronic atrophic gastritis and intestinal metaplasia (a set of small lesions) resulting from chronic gastric inflammation related to H. pylori infection;
• Diffuse – the diffuse type occurs in younger patients, with an equal distribution between sexes, and has a more aggressive behavior compared to the intestinal type. It originates from the normal gastric epithelium, without apparent precancerous lesions, and may be related to a genetic mutation (of a gene called CDH1).

Symptoms and signs of stomach cancer

There are no specific symptoms of stomach cancer that lead to a rapid identification of stomach cancer. However, some signs may indicate the development of a stomach tumor:

• Weight loss;
• Loss of appetite;
• Fatigue;
• Feeling of fullness in the stomach;
• Difficulty swallowing;
• Vomiting;
• Nausea;
• Persistent abdominal discomfort.

These symptoms, however, are common to various other benign conditions, such as ulcers and gastritis. Therefore, experiencing them is not synonymous with having stomach cancer. It is necessary to consult with a specialist experienced in detecting the symptoms and signs of the disease.

During the physical examination, the patient with cancer may feel pain when the stomach is palpated. If there is an enlargement of the liver and the presence of a lump in the lower left area of the neck and nodules around the navel, the doctor may consider them as indications that the disease is in a more advanced stage.

Vomiting with blood occurs in about 10% to 15% of stomach cancer cases. Additionally, changes such as blood in the stool, dark and pasty stools, and very strong-smelling stools (indicative of digested blood) may be observed.

Diagnosis of stomach cancer

Diagnosis of stomach cancer is done through upper gastrointestinal endoscopy. To perform this exam, the patient is sedated with the assistance of an anesthesiologist.

Upper gastrointestinal endoscopy allows the doctor to visualize the esophagus and stomach, as well as to take biopsies (removal of small tissue samples). The biopsy material is sent to a laboratory to confirm (or not) the diagnosis of a malignant tumor and define its type.

If the diagnosis of gastric cancer is confirmed, additional tests may be necessary to assess the extent of the disease. This process is called staging and involves the performance of a computed tomography (CT) scan of the chest and abdomen.

On the other hand, when the cancer appears to be in an earlier stage, endoscopic ultrasound (a procedure similar to upper gastrointestinal endoscopy, in which an ultrasound device is attached to the end of a tube inserted through the throat) may be indicated for a more accurate staging.

Depending on the case, the doctor may choose to perform a more invasive evaluation through laparoscopy. This is an exploratory surgery usually done by video. In this procedure, the medical team investigates whether the cancer has spread beyond the stomach (metastasized) to a membrane that lines the internal organs called the peritoneum. This laparoscopy is a diagnostic surgical procedure performed by the surgeon. In this procedure, the surgeon makes small incisions in the abdomen and inserts a special camera that transmits images to a monitor in the operating room.

Treatment

The treatment options for stomach cancer depend on its location, stage, and aggressiveness. Additionally, the overall health of the patient and their preferences are taken into account by the doctor. Here are the main treatment alternatives available:

Surgery – The main goal of surgery is to remove all cancer and also a portion of the healthy tissue around it, a procedure called surgical margin. The types of surgery for stomach cancer are:

• Partial removal of the stomach (subtotal gastrectomy);
• Complete removal of the stomach (total gastrectomy);
• It is important to note that standard oncological surgery for stomach cancer with curative intent involves removing the tumor in the stomach along with the removal of local/regional lymph nodes.

In patients with advanced disease and no curative prospects, surgery with palliative intent may be indicated to alleviate symptoms.

Chemotherapy – It can be initiated before surgery (called neoadjuvant) to help shrink the cancer, thus facilitating its removal. It can also be prescribed after surgery (adjuvant chemotherapy) to eliminate any remaining cancer cells that are not detectable by imaging tests.

Radiation therapy – In advanced cancer that cannot be operated on, radiation therapy can be used to control symptoms such as bleeding, which can occur as the tumor grows. Depending on the case, the doctor may combine chemotherapy with radiation therapy.

In advanced cancer that cannot be operated on, radiation therapy can be used to alleviate adverse effects such as bleeding, which can occur as the tumor grows. Depending on the case, the doctor may combine chemotherapy with radiation therapy.

Targeted therapies – Targeted therapies focus specifically on the weak points of cancer cells, leading to their death. In gastric cancer, the use of targeted therapies is usually associated with chemotherapy.

Immunotherapy – Immunotherapy is a treatment that helps the immune system fight cancer. Normally, the immune system cannot attack cancer because cancer cells produce proteins that make it difficult for immune cells to recognize them as dangerous. Immunotherapy works by interfering with this process.

Prevention

There are several factors that can increase the risk of stomach cancer:

• Gastroesophageal reflux disease;
• Obesity;
• High-sodium (salt) and smoked food diet;
• Low intake of fruits and vegetables;
• Family history;
• Infection with the H. Pylori virus;
• Stomach polyps;
• Smoking.

To reduce the risk of developing stomach cancer, it is important to avoid the factors described above.

Maintaining a healthy weight according to your age, height, and body structure, opting for a diet with more natural ingredients, focusing on vegetables and fruits, reducing the amount of salt and processed foods in your diet, and not smoking are actions that decrease the risk of the disease.