Understanding Stomach Cancer. What Are the Risks, Treatment & Prevention?

Cancer is composed of abnormal cells that increase even though the body has no use for them. In most cancers, the faulty cells develop to create a mass or lump. Cancer cells can spread to neighboring regions if they remain in the body long enough. They are even capable of spreading to other organs (metastasis). Among all cancers, stomach cancer is the fifth most frequent. It ranks as the fourth most prevalent cancer for men, while for women, it ranks as the seventh most common. By 2020, there had been over a million new instances of stomach cancer.

The stomach is a component of the gastrointestinal system responsible for breaking down and digesting food and removing waste from the body. There are five distinct stomach layers. Stomach cancer most frequently develops in the mucosa, the innermost layer of the stomach. Small changes occur in the DNA of stomach cells, telling them to multiply and forming an abnormal growth which we call a tumor. It can develop when the cells that line your stomach transform and expand uncontrollably. The medical term for his tumor is adenocarcinoma.

The annual number of cases of stomach carcinoma in the United States is estimated at 25,000 by the American Cancer Society. Due to the lack of early signs, stomach cancer is commonly identified at an advanced stage. This makes it more challenging to treat.

Types of Stomach Cancer. 

Adenocarcinomas make up most stomach cancers (almost 90%), which begin in the cells producing mucus and other fluids. Other, less common forms of stomach cancer include:

• Gastrointestinal stromal tumor (sarcoma): It is an uncommon form that develops in a specific kind of cell in the stomach lining called interstitial cells of Cajal (ICCs). Cells from a GIST appear like muscle or nerve cells under the microscope. However, these tumors can appear anywhere in the digestive system but usually develop in the stomach (60–70% cases). These tumors may also bleed, causing blood to appear in the vomit and stool, promoting people for a doctor’s visit.
• Carcinoid tumors of the GI tract: Carcinoid tumors originate in the stomach’s hormone-making cells. These tumors cause approximately 3% of all carcinoma cases and seldom metastasize to other organs.
• Lymphomas: Lymphoma is a malignancy of immune system tissue that can begin in any organ where lymph tissues are present, including the stomach. However, stomach lymphomas are uncommon, accounting for around 4% of all stomach malignancies.
• Hereditary Diffuse Gastric Cancer (HDGC): Hereditary diffuse gastric cancer (HDGC) accounts for just 1% to 3% of all cases of stomach cancer, citing data from the National Cancer Institute. This hereditary carcinoma forms in numerous stomach sections and spreads swiftly to other body parts. An individual’s susceptibility to HDGC can be determined by genetic testing and familial history.

Risk Factors

• Bacterial Infection: Some research suggests that bacterial infection (with Helicobacter pylori) is a key contributor to the development of stomach cancer. Stomach irritation and damage might result from a prolonged infection with these microorganisms. (1) (2).
• Genetic Mutations: About 5% of cases of stomach cancer may be traced back to a malfunction in the CDH1 gene. CHD1 mutations increase the risk of gastric cancer.
• Age: Stomach cancer primarily affects the elderly. The average age of those diagnosed is 68 years old. About 6 out of 10 people diagnosed annually with stomach cancer are 65 or older.
• Gender: Men are more susceptible to stomach cancer than women, as common as twice times.
• Alcohol and Smoking. Like many other forms of cancer, alcohol can also be the reason for this cancer. This relationship is stronger for people who consume 3+ drinks each day. The same is true for smoking, doubling the risk of such cancer if a person smokes.
• Obesity: Overweight and obesity are key contributors to developing several types of cancer, including stomach cancer. CDC reports find that those who are overweight or obese are twice as likely to acquire stomach cancer as those with a BMI between 18.5 and 24.9.
• Racial Difference: Hispanics and blacks have a greater stomach cancer risk than whites. In comparison, the Asian and Pacific Islander population has the highest rates.
• Family History: Those with multiple relatives diagnosed with stomach cancer are at a higher risk of developing the disease.
• Previous Stomach Surgery. People who have undergone curative surgery on their stomach for conditions like ulcers are at an increased risk of developing this cancer in the future. Lower acid production in the stomach might be to blame for this since it would allow for an increase in potentially dangerous bacteria. It manifests itself years after the surgery.
• Blood Group: It has been studied that people with type A blood have an increased chance of developing stomach cancer for unexplained causes.
• Polyps Formation: Most polyp types do not increase the risk of stomach cancer. Specifically, adenomatous polyps have been linked to an increased risk of this kind of cancer.

Signs and Symptoms.

Cancer of the stomach usually evolves gradually over a long period. Before full-fledged cancer develops, pre-cancerous modifications commonly occur in the stomach’s inner lining (mucosa). This is because these changes occur before symptoms appear. Thus, they are frequently missed. Signs of other gastrointestinal issues, such as ulcers or infection, might be easily mistaken. Here are a few possible red flags:

• Abdominal pain
• Difficulty in Swallowing
• Heartburn, indigestion, or ulcer-type symptoms
• A feeling of bloating, fullness, or fullness followed by pain or discomfort in the stomach.
• The feeling of fullness following a light meal.
• Diarrhea or sickness
• Experiencing blood loss through vomiting or diarrhea.
• There’s been a mysterious drop in weight.

Even the most frequent early indicators of stomach cancer, unexplained weight loss, and stomach discomfort, don’t appear until the disease has advanced. Many people, including medical professionals, may not detect stomach cancer as a major factor in its late diagnosis. Black stools are a rare indication of stomach cancer that often manifests in the latter stages of the disease (a sign of bleeding in the stomach). It is always wise to consult your physician if you have any of these symptoms. Even if the cause is not stomach cancer, they may be symptoms of other treatable health conditions.

Diagnosis & Staging.

Unfortunately, gastrointestinal cancer is typically not recognized until it has progressed significantly since its early stages are rarely accompanied by any noticeable symptoms. The first step in diagnosing stomach cancer begins with a thorough physical examination and an overview of your family history. This will assist in identifying recognized risks for this type of cancer. In addition to standard physical examinations, the following tests can help detect stomach cancer in patients with various symptoms or risk factors.

• Blood Test. The doctor might suggest a blood test to check for anemia that the cancer bleeding could cause in the stomach. Another test that is utilized is the fecal occult blood test. This test can detect hidden blood in the feces. This method requires only a tiny bit of feces to be collected on a specific card, analyzed at the doctor’s office, or submitted to a lab.
• Tumor markers. They are specialized marker antigens that are used to support the diagnosis of cancers. The tumor markers reported in this type of cancer are CEA, CA 72-4, and CA 19-9. For a detailed overview and insight into all the tumor markers and their efficacy in case of stomach malignancies, refer to our article here.
• Endoscopy. For this procedure, the doctor will place an endoscope (a thin, flexible, illuminated tube with a tiny video camera at the end) into your throat. Your doctor can examine your esophagus, stomach, and the beginning of your small intestine in this way. The endoscope can insert instruments to remove biopsy samples from suspicious regions. Tissue samples are evaluated for the presence of cancer in a laboratory setting. In certain situations, endoscopy can be utilized to remove tumors in their earliest stages. Additionally, it can be used to prevent or alleviate symptoms and other problems of stomach cancer without the need for more extensive surgery.
• Biopsy.  During an endoscopy, if the doctor notices anything out of the ordinary with the stomach lining, he or she can send biopsy tools through the endoscope to take a deep insight. A biopsy involves the surgical removal of a tiny tissue sample from a suspicious location. Upper endoscopy is the preferred method for doing biopsies to detect cancer. A lab will examine the biopsy specimens under a microscope. The samples are analyzed to determine the presence and kind of malignancy.
• Radiological Screening.

Tumors and other abnormalities that may be cancer-related can be detected by radiologic testing, such as a CT scan, barium swallow, or MRI. Consuming barium before an X-ray examination allows doctors to examine the stomach’s lining better. If cancer has spread to other parts of the body, a PET scan will show it.

Staging.

Cancer staging is often done using the American Joint Committee on Cancer’s TNM method. This helps doctors to plan the best treatment regimen for the patient and is always used with other methods of diagnosis and detection. Three factors are taken into account by the system.

• T: Tumor size and spread.
• N: Amount of lymph node metastasis.
• M: The M category assesses whether or not cancer has metastasized (spread) to other body parts.

Results from each group are added together to obtain a score from 0 to 4. As the stage of cancer decreases, the likelihood of survival increases. Each stage is represented in the clinical method as follows,

It will be between stages 0 and 3 if cancer hasn’t spread to other places of the body. Stage 4 stomach cancer is diagnosed when the disease has spread to other parts of the body. As cancer spreads more into the body, a patient’s prognosis worsens. Like other types of cancer, a malignant tumor can grow in the stomach, spread to the liver, pancreas, and intestines, and even further through the circulatory system to the lymph nodes, bones, and lungs.

Treatment. 

The outcome of stomach cancer has substantially improved over the past two decades as our understanding of the condition has grown. Reasons for this growth include the introduction of novel treatments and the refinement of surgical and postoperative care. Still, if anyone is suggested to go for a treatment, health care professionals employ the following methods to treat the disease and extend the lifespan.

1. Surgery

Treating stomach cancer in its early stages may be a viable option. A preoperative examination is important since the type of surgery is determined by the size and location of the tumor. The two most common kinds of gastric surgery are partial and complete. The histological pattern of the tumor, the tumor’s size and extent, and its location all play a role in deciding what kind of resection will be performed.

Surgeons often remove lymph nodes during surgery due to the possibility of cancer spreading to them.  This operation is known as lymph node removal. Even when stomach cancer has progressed to an advanced stage, surgery may be recommended to lessen the risk of consequences such as organ obstruction or internal bleeding. Among those who had their tumors removed surgically, the 1-year, 3-year, and 5-year survival rates were 82.7%, 46.3%, and 31.1%, respectively.

2. Radiotherapy.

Radiation treatment, commonly known as radiotherapy, involves using X-rays and other focused radiation beams to kill cancer cells. Patients typically undergo external-beam radiation treatment, in which radiation is delivered by a machine rather than a human being. Before surgery, radiation can reduce the size of the tumor, and after surgery, it can eliminate any leftover cancer cells.  It is usually used with chemotherapy after surgery to eliminate any cancer cells missing during the first procedure, as it is not useful as a sole treatment.

Radiotherapy has the potential to be helpful in the treatment of advanced stomach cancer by removing obstructions in the digestive tract. Blood loss from inoperable tumors may also be stemmed with this method. Side effects include tiredness, moderate skin responses, stomach distress, and loose stools. The majority of adverse effects disappear shortly after therapy has ended.

3. Chemotherapy.

The goal of chemotherapy (chemo) is to reduce the size of cancer cells so that they may be more easily removed during surgery or after surgery. Bioactive molecules are used in chemotherapy to reduce the number and size of malignant tumors.  Additionally, chemotherapy can be used to eradicate any cancer cells that may still be present following surgery. After surgery, it may be administered alone or in conjunction with radiation. For patients with advanced stomach cancer who are no longer surgical candidates, it may also be utilized to alleviate their symptoms or extend their life expectancy.

Usually, 2-3 drugs, are used and these medicines are commonly combined (sometimes along with a targeted drug as well). This depends on the cancer’s stage, the patient’s condition, and if chemo is paired with radiation.

4. Targeted Therapy

As researchers understood more about cancer-causing cell mutations, they devised new medications to target them. The doctor may investigate your tumor’s genes, proteins, and other features to select therapy. Targeted therapy is rapidly becoming the preferred method of treating cancer because of its superior efficacy over chemotherapy. In contrast to chemotherapy’s 30% success rate, tailored treatment can achieve this goal in as many as 80% of patients.

• HER2 Therapy. Overexpression of the growth-promoting HER2 protein on the surface of cancer cells has been linked to some cases of stomach cancer. One such synthetic antibody is trastuzumab (registered trademark Herceptin®), which inhibits the activity of the HER2 protein in cancer cells. This medication improves survival in individuals with HER2-positive, advanced stomach cancer when used with chemotherapy.
• Anti-angiogenesis Therapy. Anti-angiogenesis drugs are intended to stop the production of new blood vessels, also known as angiogenesis. The purpose of anti-angiogenesis therapy is to essentially “starve” a tumor by cutting off its supply of nutrients, which it receives through new blood vessels.

5. Immunotherapy.

This type of treatment aids your immune system in identifying and eliminating cancer cells that may be difficult to detect. It is often reserved for cases of advanced or recurrent malignancy. Opdivo (nivolumab) in conjunction with some forms of chemotherapy, has been given the green light by the U.S. Food and Drug Administration in 2021. Immunotherapy can produce varying side effects. Skin rashes, flu-like symptoms, diarrhea, and weight fluctuations are common.

6. Palliative Care.

A cancer patient’s quality of life can be greatly enhanced by receiving palliative care. Medical professionals such as physicians, nurses, and others trained to alleviate suffering through palliative care are available. They may also be able to give one supplementary help that will supplement the services of their usual doctors. Palliative care can be provided in conjunction with other medical interventions.

It’s important to discuss the desired outcomes of each therapy modality with your doctor before beginning treatment. You should also discuss palliative care choices and any potential adverse effects of the prescribed therapy.

7. Nutrition Management.

Feeling better, keeping your strength up, and recovering faster from cancer treatment are all possible outcomes of a healthy diet.  Improved nutritional status, metabolism, adherence to potential anticancer medicines, quality of life, and disease progression are all possible outcomes of nutritional therapy.

• Know The Risk: Both stomach cancer and its treatment can raise the likelihood of nutritional problems, including malnutrition. Health problems, hospitalizations, and a lower quality of life are all things that can be brought on by malnutrition. Weight loss or other symptoms should be reported to your healthcare provider.
• Maintain Healthy Weight: Keep your weight steady throughout treatment. When undergoing cancer treatment, a strict diet is not advised. Energy levels and the immune system’s capacity might also drop as you lose weight.
• Smaller Meals= Better Results: Eating frequently and in little amounts can help you maintain a healthy weight and ensure your body has the energy and nutrition it needs to deal with therapy. Eating fewer, smaller meals may also lessen treatment-related nausea. Try spacing out your meals to around every three hours, with five or six smaller meals.

In conjunction with symptomatic therapy, the nutrition and its consistency must be modified to the symptoms.

 Prevention.

Many incidences of stomach cancer can still be avoided even though its precise origin is still unknown. Early detection may be the best strategy to increase the likelihood of effective treatment and decrease the number of deaths caused by the diseases.

Fruits and Veggies: The antioxidants included in fruits and vegetables have been shown to aid in the body’s combat against cancer.  Eat at least five servings of fruit and vegetables every day.

Use of Alternative Methods for Food Storage: Stomach cancer rates has decreased over the past 60 years due to changes in nutrition and the widespread adoption of refrigeration for food preservation (as opposed to salting, pickling, and smoking).

It is unclear at this time if patients who have had a Helicobacter pylori infection for a long time should be treated to reduce their risk of developing stomach cancer. The research on this subject continues.