What is Stomach Cancer?

Stomach cancer, also called gastric cancer, occurs when cancer cells form in the inner lining of the stomach. The 5-year survival rate for localized stomach cancer is 75%. Men are statistically more likely to develop stomach cancer compared to women, and those over 55 should be aware of the signs.

The stomach on the left side of the upper abdomen breaks down food. It is part of the digestive system, a series of connected organs that process food from the mouth to the anus.

In most cases, stomach cancer grows into the gastroesophageal junction (the place where the stomach meets the esophagus).

What Causes Stomach Cancer?

Stomach cancer starts when there is a change (mutation) in the DNA of stomach cells. DNA acts like a set of instructions for cells, telling them when to grow and when to die. When a mutation happens, the cells grow too quickly and form a tumor instead of dying off.

These cancer cells can then take over healthy cells and may spread to other body parts (metastasize). Advanced stomach cancer may not be operable, and different treatments like immunotherapy and targeted therapies can enhance patients' survival and response to treatment.

The main reason for mutation is unknown. Yet, there are several factors putting patients at risk of stomach cancer:

• 🦠 Helicobacter pylori infection. Long-term infection of the stomach lining with H. pylori bacteria is a considerable risk factor. The bacterium spreads through direct contact with saliva, vomit, or stool.

• 🙋🏼‍♀️ Family history.

• 🍔 Diet. Eating salty food and having poorly preserved products regularly.

• 👷🏽‍♂️ Occupational exposures, for example, working in a rubber or coal industry.

• 🚬 Tobacco use.

What are the Types and Stages of Stomach Cancer, including Gastric Cardia Adenocarcinoma?

The doctors classify stomach cancer into the following types:

• Adenocarcinoma. It is the most common type of stomach cancer. Adenocarcinoma starts in the cells that produce mucus;

• Gastrointestinal stromal tumors (GIST). GIST is a type of cancer that starts in particular nerve cells found in the walls of the stomach and other digestive organs. It belongs to a group of cancers called soft tissue sarcomas.

• Lymphoma. A slow-growing tumor that responds well to early treatment. Over 90% of stomach lymphomas are associated with Helicobacter pylori infections.

• Leiomyosarcoma. It is an aggressive tumor, one of the subtypes of sarcoma. Leiomyosarcoma starts in a muscle layer and is extremely rare in the stomach area.

The stages of stomach cancers depend on the severity of cancerous cell growth and spread. Different systems describe how far cancer has spread. For stomach cancer, doctors often use the TNM staging system. It stands for Tumor-Node-Metastasis and helps to measure cancer progression and coordinate treatment plans. Different stages require different approaches to treat stomach cancer, including surgery, chemotherapy, and radiation therapy.

The stomach wall has five layers:

• Mucosa. Contains glandular cells that make mucus and digestive juices;

• Submucosa, which has blood vessels, lymph vessels, and nerves.

• The muscle layer helps mix food and move it to the small intestine.

• The subserosa and serosa are the outer layers, with the serosa being the outermost.

Stomach cancers become advanced as they spread across different wall structures. There are five main stages of disease progression (table 1)

• Stage 0 (carcinoma in situ). The abnormal cancer cells grow into the mucosa, the innermost layer of the stomach wall;

• Stage I (also called stage 1). The stomach cancer may spread to the submucosa or even the muscle layer;

• Stage II (also called stage 2). Cancer cells spread to the nearby lymph nodes and deeper into the stomach wall;

• Stage III (also called stage 3). This stage has three sub-stages. The disease spreads all over the stomach wall and can even reach the other organs (such as spleen, colon, liver, diaphragm, or pancreas);

• Stage IV (also called stage 4). The cancer spreads to all body parts, including the lungs and liver.

What Are the Warning Signs of Stomach Cancer, including Lymph Nodes Stomach Cancer Symptoms?

The early signs of stomach cancer include:

• 🔥Heartburn;

• 😶‍🌫️ Bloated feeling after eating;

• 😰 Indigestion;

• 🤢 Mild nausea;

• 🧩 Changes in appetite;

• 😖 Stomach pain.

Stomach cancer doesn’t often cause many symptoms in the early stages. In the same way, it may not appear at the Stage IV. Most symptoms are purely digestive, and the rest depend on the organs where cancer spreads.

How to Detect Stomach Cancer Early?

Diagnosing stomach cancer typically involves:

• Physical exam to assess the overall health;

• Medical history to check if anyone blood-related has stomach cancer;

• Blood tests. Doctors may order a blood test to check for anemia, which can result from cancer, causing internal bleeding in the stomach. Another test may look for hidden blood in the stool, indicating stomach bleeding;

• Instrumental tests.

The instrumental methods are:

Upper endoscopy with biopsy

An upper endoscopy allows doctors to look inside the esophagus, stomach, and the first part of the small intestine. A thin, lighted tube called an endoscope is passed through the mouth and throat. A small tissue sample (biopsy) can also be taken to check for signs of cancer under a microscope.

Barium swallow

The patient drinks barium (a silver-white metallic compound) and then undergoes a series of X-rays. The liquid coats the esophagus and stomach, increasing their visibility and improving the chances for tumor diagnostics.

Biomarker testing

Biomarker testing checks for specific genes, proteins, and other substances in the body, known as biomarkers or tumor markers. These biomarkers can give insights into stomach cancer and its treatment response.

The most popular markers of stomach cancer include:

• HER2;

• PD-L1;

• Microsatellite instability;

• NTRK.

PET-CT scan

A PET-CT scan combines images from a positron emission tomography (PET) scan and a computed tomography (CT) scan. Both scans are done at the same time using the same machine. Combining the images provides a clearer, more detailed picture than either scan alone.

Magnetic resonance imaging (MRI) with gadolinium

The other name for the procedure is nuclear magnetic resonance imaging (NMRI). Before scanning, the patient receives a gadolinium injection for a brighter stomach image. The substance gathers around cancer cells, making the tumor more visible and sharp in pictures.

How to Treat Stomach Cancer at Early Stages?

In some cases of stage 1 stomach cancer, doctors may recommend surgery to remove part or all of the stomach. For stage 2 and stage 3 stomach cancers, surgery is often not the initial treatment option.

The main approaches for treating stomach cancer include:

Surgery

In stage I-II, the doctors may solve the problem by simply removing the cancerous part of the stomach. At some medical centers, these operations involve laparoscopic gastrectomy. The other facilities prefer robotic-assisted surgery for these procedures.

Sometimes, surgery is an option for palliative care. If the cancer has spread too much to be removed entirely, it helps to stop bleeding from the tumor. It’s the solution to manage symptoms and relieve pain or at least prevent the stomach from becoming blocked by the tumor's growth. 

When stomach cancer blocks digestion, doctors use several procedures to improve quality of life:

• Endoluminal Stent Placement. Surgeons place a thin, expandable tube (stent) from the esophagus to the stomach or from the stomach to the small intestine when a tumor blocks the passage. This procedure allows normal eating by reopening the pathway.

• Endoluminal Laser Therapy. Doctors use a thin, lighted tube with a laser attached, to cut through blockages in the gastrointestinal tract. The laser acts like a knife to clear the obstruction.

• Gastrojejunostomy. Surgeons remove the tumorous part of stomach cancer that blocks the small intestine. They then connect the remaining part of the stomach to the jejunum, a section of the small intestine, to restore the normal flow of food and medicine.

Chemotherapy

Oncologists mostly combine chemotherapy with surgery in case of locally advanced disease, which spreads to the nearby lymph nodes. Chemotherapy utilizes medications to destroy cancer cells, specifically highlighting its application in treating various types of stomach cancer.

• Chemo before surgery is known as neoadjuvant treatment. It can make the surgery more accessible by “shrinking” the tumor. It can also reduce the risk of cancer returning and extend life expectancy (5-year survival rate increases to 38% compared to 24% for perioperative chemotherapy);

• Chemo after surgery (or adjuvant treatment) aims to kill any left-out cancer areas that are hard to see. It helps to prevent stomach cancer relapse. Often, the doctors prescribe chemotherapy with radiation therapy after surgery to ensure no traces of cancer cells have left.

Targeted Drug Therapy

Targeted drug therapy works on specific proteins in cancer cells or other aspects of tumors.

The latest recommendations to treat stomach cancer include:

• Tyrosine kinase inhibitors to slow cancer growth;

• Cell structure remodeling therapies to destroy cancer cells by stimulating their death;

• Targeting of DNA damage repair proteins, which cause a normal cell to mutate into a cancer cell. These proteins lead to ineffective repairing of genetic material, increasing the potential for tumor growth;

• Immunotherapy stimulates the body’s response to disease by activating its immune system to identify and combat stomach cancer cells, highlighting its advantages over traditional treatments like chemotherapy.

When Is It Better to Apply Radiation Therapy?

Radiation therapy aims to target stomach cancer with precise radiation from different angles. It helps to focus on mutated areas without damaging the healthy tissues. Doctors at stomach cancer treatment centers apply the following procedures:

• 📌Three-dimensional conformal radiation therapy (3D-CRT);

• 📌Intensity-modulated radiation therapy (IMRT);

• 📌Respiratory gating is a supplement technique before surgical resection of the stomach.

Radiation therapy can be applied in several cases, depending on how advanced stomach cancer is:

• For some earlier-stage cancers, the top stomach cancer treatment centers combine radiation therapy with chemotherapy. This approach makes tumor removal much easier and is called chemoradiation.

• After surgery, radiation therapy, along with chemotherapy, may target any remaining cancer cells that couldn't be removed during the operation. This approach aims to reduce the chances of stomach cancer recurrence.

• For cancers that can't be removed with surgery, radiation therapy can sometimes slow the tumor's growth and help relieve symptoms like pain, bleeding, or difficulty eating.

How Does Diet Contribute to the Risk of Stomach Cancer?

The studies show that a higher intake of fruits and vegetables lowers the risk of stomach cancer by 13-25%. This suggests that including more fruits and vegetables could reduce the likelihood of developing stomach cancer.

The main reason why these food groups are so influential is that they prevent DNA damage. Fruits and vegetables often have many antioxidants, working against cell mutation and abnormal tumor growth.

How To Find the Best Hospital for Stomach Cancer?

Searching for the best stomach cancer hospital in the world requires precise attention to the following details:

• 🏥Center's location. Bookimed advises picking the country that is faster to reach. Depending on the cancer stage and severity, there might be less to zero time for itinerary changes. That's why the best hospital for gastric cancer is the one patients can access via direct flight.

• 🏥Oncologist's qualification. Acknowledged specialists hold certifications and receive positive patient feedback. The top stomach cancer hospitals have technological advancements, such as robotic surgery and precise radiation therapy tools.

• 🏥Hospital affiliations. What kind of specialists work in the hospital? What is the cost of stomach cancer treatment? What support staff is available? Answering these questions will help to reduce anxiety before starting a treatment course.

Where are the Best Gastric Cancer Hospitals Located?

Bookimed has a rating of the best stomach cancer treatment centers. Based on our Smart Ranking System, most are in Germany, Izrael, and Turkey. They have modern equipment for diagnosis and treatment, such as:

• DaVinci Surgical system is a method of interventional radiology similar to traditional laparoscopy. However, the DaVinci system makes a few small incisions rather than a large one.

• GammaKnife, which is applicable for brain metastases of stomach cancer. The mechanical accuracy of GammaKnife is less than 0.3 millimeters, making incisions practically invisible to patients.

• NanoKnife. It involves placing long, thin needles directly into the tumor to deliver targeted therapy. NanoKnife is an option for patients with inoperable stomach cancer or if they do not qualify for other treatment options.

What is the Gastric Cancer Treatment Cost?

Today, stomach cancer screening and treatment are relatively cheap. For example, the total cure for stomach cancer starts from $20,000, while

the gross payment for prostate cancer begins from $33,607.

Here's an overview of the best hospitals for gastric cancer treatment in Europe and their estimated prices for diagnostics and treatment.

*The prices may vary depending on the center's policy, exchange rates, etc. The Bookimed MD will suggest the total cost after reviewing each individual case. 

References

1. Fruit and vegetable intake about gastric cancer risk: A comprehensive and updated systematic review and dose-response meta-analysis of cohort studies. PubMed Central (PMC). URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9939448/ (date of access: 06.09.2024).

2. Gastric Cancer: A Comprehensive Review of Current and Future Treatment Strategies. PubMed Central (PMC). URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7680370/ (date of access: 06.09.2024).

3. Gastric cancer: a comprehensive review of current and future treatment strategies - Cancer and Metastasis Reviews. SpringerLink. URL: https://link.springer.com/article/10.1007/s10555-020-09925-3#article-info (date of access: 06.09.2024).

4. Gastric Lymphoma - StatPearls - NCBI Bookshelf. National Center for Biotechnology Information. URL: https://www.ncbi.nlm.nih.gov/books/NBK567799/ (date of access: 06.09.2024).

5. Stomach Cancer Diagnosis and Tests. Comprehensive Cancer Information - NCI. URL: https://www.cancer.gov/types/stomach/diagnosis (date of access: 06.09.2024).

6. Stomach motion and deformation: implications for pre-operative gastric cancer radiotherapy / M. Bleeker et al. International Journal of Radiation Oncology*Biology*Physics. 2023. URL: https://doi.org/10.1016/j.ijrobp.2023.08.049 (date of access: 08.09.2024).