Stomach cancer, also known as gastric cancer, refers to cancer that starts in the stomach. It is a relatively common type of cancer, but early detection greatly improves chances for successful treatment. There are several different types of stomach cancers, and prognosis can vary depending on the specific subtype. However, with advances in diagnosis, staging, and treatment, cure rates for stomach cancer have improved over the last several decades.
What are the different types of stomach cancers?
The stomach has several anatomical regions, and cancers can start in any part of the stomach. The different types of stomach cancers include:
- Cancer of the proximal stomach – This starts in the upper portion (closest to the esophagus)
- Cancer of the distal stomach – This starts in the lower portion (closest to the small intestine)
- Cancer of the gastric cardia – This starts in the area where the esophagus joins the stomach
- Cancer of the gastric fundus – This starts in the upper part of the stomach
- Cancer of the gastric body – This starts in the main part of the stomach
- Cancer of the gastric antrum – This starts in the lower part of the stomach
- Cancer of the pylorus – This starts in the furthest part of the lower stomach, right next to the small intestine
The most common type is cancer of the distal stomach, accounting for 50-60% of gastric cancers. The location of the tumor can affect symptoms and outlook.
What causes stomach cancer?
Researchers do not fully understand the exact causes of stomach cancer, but these factors are believed to increase risk:
- H. pylori infection – The bacteria Helicobacter pylori is a major risk factor, responsible for around 60% of stomach cancer cases.
- Diet – Diets high in smoked, pickled, or salty foods seem to increase stomach cancer risk. Low fruit and vegetable intake may also contribute.
- Smoking tobacco – Smokers have around twice the risk of developing stomach cancer compared to non-smokers.
- Genetics and family history – People with close relatives who have had stomach cancer have a higher risk.
- Previous stomach surgery – Those who have had certain stomach surgeries, like to remove ulcers, are more susceptible.
Other potential risk factors include obesity, radiation exposure, workplace exposure (coal dust), and Epstein-Barr virus infection. Age and gender also play a role, as stomach cancers mostly affect older individuals and are more common in men.
What are the symptoms of stomach cancer?
Stomach cancer often does not cause specific symptoms in its early stages. As the cancer grows, symptoms may include:
- Feeling bloated or full after eating only a small amount
- Frequent heartburn or indigestion
- Nausea and vomiting
- Increased abdominal pain and discomfort
- Feeling very tired and weak
- Loss of appetite and unexplained weight loss
- Dark stool from occult (hidden) blood
- Anemia from bleeding within the stomach
Unfortunately, these vague symptoms overlap with many other benign conditions. Stomach cancer tends to be diagnosed at later stages after symptoms have worsened. Early detection greatly improves prognosis.
How is stomach cancer diagnosed?
If stomach cancer is suspected based on risk factors and symptoms, these tests may be used to make a diagnosis:
- Endoscopy – A gastroscopy procedure allows the doctor to visually examine the lining of the stomach and take biopsies of any concerning lesions.
- Barium swallow radiography – The patient swallows a liquid containing barium, which coats the stomach and shows up on x-rays. This can reveal abnormalities.
- CT scan – A computed tomography (CT) scan takes cross-sectional x-ray images of the abdomen to look for tumors.
- PET scan – A positron emission tomography (PET) scan can find cancer deposits based on their increased metabolic activity.
- Laparoscopy – In this surgical procedure, a camera instrument is inserted through the abdomen to look directly at the stomach.
If cancer is confirmed, further testing will be done to determine the stage and grade of the tumor. This helps inform prognosis and guides treatment planning.
What are the stages of stomach cancer?
Staging describes how far the stomach cancer has spread within the body. Higher stages indicate more advanced disease.
Stage 0 – Cancer is only in the innermost stomach lining.
Stage I – Cancer is growing in the layers below the inner lining but has not spread deeper into the stomach wall or other organs.
Stage II – Cancer has spread through the stomach wall into the muscle layer or nearby lymph nodes.
Stage III – Cancer has spread to the major blood vessels and/or more lymph nodes but not distant organs.
Stage IV – Cancer has metastasized to distant sites like the liver, lungs, bones, or brain.
Knowing the stage guides treatment options and helps determine patient prognosis. Earlier stage cancers confined to the stomach have better outcomes.
How is stomach cancer treated?
Treatment plans are tailored to each patient’s cancer characteristics and overall health status. Options may include:
Surgery – For earlier stage cancers, removing part or all of the stomach (gastrectomy) gives the best chance at a cure. Nearby lymph nodes are also removed.
Chemotherapy – Drugs that damage cancer cells are given systemically, usually before and/or after surgery. This helps eliminate any stray cancer cells.
Radiation – High energy radiation beams delivered externally target cancer sites. This can reduce recurrence risk.
Targeted therapies – Advanced cancers may be treated with newer drugs that focus on specific molecular abnormalities in cancer cells.
Treatment often involves a combination of surgery, chemotherapy, radiation, and sometimes targeted therapy for more advanced disease. The goal is to remove all detectable stomach cancer.
What are the survival rates for stomach cancer?
Survival rates give an estimate of the percentage of people with a given cancer type who will survive for a designated period of time after diagnosis. However, each individual’s outlook can vary.
For all stages of stomach cancer combined, general 5-year survival rates are:
– Stage 0 – Greater than 95%
– Stage I – 80-90%
– Stage II – 50-70%
– Stage III – 20-40%
– Stage IV – Less than 10%
But 5-year survival rates for early stage stomach cancer confined to the stomach can be significantly higher, in the range of 90-95% or greater with proper treatment and follow-up.
So early diagnosis and treatment are critical for improving stomach cancer prognosis. Patient factors like overall health and response to therapy also affect individual outcomes.
Can stomach cancer be prevented?
There is no guaranteed way to prevent stomach cancer, but these steps may lower risk:
– Getting tested and treated for H. pylori infection, especially if at higher risk
– Eating a diet centered around vegetables, fruits, whole grains – avoid processed and salty foods
– Quitting smoking and avoiding secondhand smoke
– Avoiding known occupational risk factors if possible
– Managing other conditions like obesity and GERD
Early detection is also key. People with stomach cancer risk factors or concerning symptoms should speak to their doctor about screening endoscopy. Treating precancerous changes in the stomach when they are found can prevent progression to cancer.
Conclusion
Stomach cancer refers to malignant tumors starting in the stomach. While still somewhat common and often fatal if found late, prognosis has improved in recent decades. Earlier diagnosis, improved surgical techniques, more effective chemotherapy drugs, and advanced radiation therapy have increased survival, especially for cancers detected before extensive spread.
Although some stomach cancers grow and spread rapidly, many cases can be treated successfully if found early. Symptoms like indigestion and abdominal pain often overlap with benign conditions, emphasizing the importance of recognizing risk factors and undergoing appropriate screening.
Research continues on better understanding stomach cancer biology, refining classification, and developing targeted drugs. Prevention is also a focus. All in all, with a combination of increased awareness, early detection, and improved treatment options, stomach cancers are certainly becoming more curable.