Health Guide for Stomach Cancer: Detecting Danger, Early and Advanced Stages

Stomach cancer, also known as gastric cancer, develops in the tissues lining the stomach. It is an aggressive disease that tends to spread quickly to other parts of the body. Stomach cancer is the 5th most common cancer worldwide and causes over 1 million deaths per year, making it the 3rd leading cause of cancer deaths globally.

Cancer begins when the cells in this mucosal lining start to grow out of control, creating a mass called a tumor. As the tumor grows, cancer cells may break away and spread (metastasize) to lymph nodes near the stomach first, before reaching more distant parts of the body.

Stomach cancer is usually one of two main histological subtypes when examined under the microscope:

Adenocarcinoma

This makes up about 90-95% of stomach cancers. The cancer develops from the cells that form the innermost mucus-producing stomach lining. There are also sub-categories of adenocarcinoma based on microscopic appearance.

Lymphoma

This cancer begins in immune system cells present in the stomach lining. Lymphoma accounts for about 4% of stomach cancers.

Other rarer subtypes like squamous cell carcinoma, carcinoid tumors and sarcomas can occasionally occur. Identifying the microscopic appearance helps determine treatment approaches.

Early and Advanced Stomach Cancers Stomach cancer is staged based on the size and spread of the tumor, which indicates how far the disease has progressed.

Early stage stomach cancers are small tumors just on the surface lining of the stomach (T1), with no or few spread to nearby lymph nodes. Patients diagnosed at these initial stages generally have better treatment outcomes.

Locally advanced stomach cancers are larger tumors (T2 or T3) that invade deeper layers of stomach tissue. The cancer has often metastasized to a greater number of nearby lymph nodes but not distant sites. At this stage, tumors can start obstructing the stomach pathway causing a backup of food when eating.

Advanced stage or metastatic stomach cancers have spread more extensively to distant lymph nodes and organs like the liver, lungs or bones through the bloodstream. Additional tumors form and grow at these distant sites. Patients are considered Stage IV at this point.

Cellular Pathogenesis

– Stomach cancer originates when healthy stomach cells accumulate genetic and epigenetic changes over time

– These changes cause cells to grow uncontrollably and avoid normal programmed cell death

– Common gene abnormalities seen in stomach cancer cells include mutations in APC, KRAS, PIK3CA, ARID1A and ERBB2 genes

Precancerous Lesions

– Chronic stomach inflammation from H. pylori infection or autoimmune conditions can cause precancerous lesions like atrophic gastritis and intestinal metaplasia 

– Over time low grade dysplasia can progress to high grade dysplasia, then finally to stomach adenocarcinoma

Angiogenesis

– As the stomach tumors grow larger, they stimulate new blood vessel formation (angiogenesis) to supply nutrients and oxygen 

– This allows for further cancer growth and provides a pathway for cells to spread hematogenously to other body sites

Invasion and Metastasis

– Cancer cells invade through the mucosal stomach lining into the muscularis propria layer underneath

– Next, they breach the serosa outer layer and can spread to nearby organs like the pancreas, spleen and colon

– Cells enter lymphatic channels to form metastatic deposits in lymph nodes

– Eventually, cells enter blood vessels to hematogenously spread to liver, lungs and bones

Paraneoplastic Syndromes

– Advanced stomach cancer may indirectly cause other issues like blood clots, skin rashes, or hormonal disorders through immune and hematologic dysfunction

The most common symptoms of stomach cancer include:

– Persistent indigestion or heartburn

– Abdominal pain or discomfort

– Nausea and vomiting

– Bloating after meals

– Loss of appetite and unexplained weight loss

– Fatigue and weakness

– Vomiting blood or coffee ground-like material

However, these symptoms may also be caused by other benign conditions. It’s important to see your doctor if you have any persistent gastric issues to determine the underlying cause.

Risk Factors

The exact cause of stomach cancer is unknown, but certain risk factors are linked to higher chances of developing the disease: 

– Age: Risk increases with age, with most cases occurring in people over 55

– Gender: Men are twice as likely to develop stomach cancer compared to women

– Diet: Eating a diet high in smoked, salted and pickled foods increases risk. A diet low in fruits and vegetables also raises the chances of getting stomach cancer.

– Bacteria: An H. pylori infection of the stomach can lead to inflammation and ulcers, which may progress to cancer over time.

– Family history: Having a first-degree relative (parent, sibling or child) with stomach cancer increases your risk.

– Previous health issues: Those who have had stomach surgery, gastric polyps or pernicious anemia have a higher risk of stomach cancer.

Prevention

There’s no guaranteed way to prevent all stomach cancers, but the following steps may lower your chances:

– Test and treat H. pylori infection if present

– Eat a nutritious diet high in fruits, vegetables and whole grains

– Cut down on processed and salted foods

– Maintain a healthy weight

– Don’t smoke cigarettes and limit alcohol intake

– Take steps to avoid exposure to asbestos and other occupational carcinogens 

If you have a family history of stomach cancer, discuss screening options with your doctor as this may detect the disease at an early and more treatable stage.

Diagnosis

Stomach cancer screening is generally not recommended for those at average risk. However, people with stomach symptoms will receive one or more of the following tests:

– Physical exam to press on the abdomen to check for abnormalities

– Upper endoscopy to examine the lining of the esophagus, stomach and first part of the small intestine

– Biopsy of stomach tissue to check for cancer cells under a microscope

– Barium swallow or upper GI series: the patient drinks a chalky liquid to coat the esophagus and stomach so they are more visible on X-rays

– CT scan of the abdomen and pelvis to create detailed cross-sectional images that can show the size, shape and position of tumors

– PET scan to analyze the metabolic activity of body tissues, helpful for detecting spread of cancer 

These tests allow doctors to confirm a stomach cancer diagnosis and determine the stage of progression.

Treatment

Treatment options for stomach cancer depend on the stage, size and position of the tumor, along with the patient’s overall health. Common treatment approaches include:

Surgery

– Removing all or part of the stomach (gastrectomy)

– Removing nearby lymph nodes

– Joining the remaining part of the stomach to the small intestine 

Chemotherapy

Using cytotoxic drugs to kill fast-growing cancer cells. Chemotherapy may be given before surgery to shrink the tumor or after surgery to kill any remaining cancer cells. Common chemotherapy drugs used include 5-FU, capecitabine, cisplatin and oxaliplatin.

Radiation Therapy

Using high-energy beams like X-rays to destroy cancer cells. Radiation may be used before surgery to shrink large tumors or post-surgery to destroy residual cancer cells.

Targeted Drug Therapy

Newer medications that specifically target cancer growth proteins or blood vessels that supply the tumor. Examples include trastuzumab and ramucirumab.

Immunotherapy

Immunotherapy stimulates the body’s immune system to identify and attack cancer cells more effectively. Pembrolizumab is an immunotherapy drug used to treat advanced stomach cancer.

Prognosis

Prognostic Factors

The stage of stomach cancer at diagnosis is the most significant prognostic factor. Other factors that negatively impact prognosis include:

– Older patient age

– Male gender

– Tumor location in the upper (proximal) part of the stomach

– Large tumor size (>5 cm)

– Diffuse type histology on microscopy

– Depth of invasion into stomach wall layers

– Higher number of involved lymph nodes 

– Positive surgical resection margins after gastrectomy 

– Presence of signet ring cells in tumor tissue

Conversely, the following are associated with better prognosis:

– Early stage disease

– Younger patient age

– Tumor located in lower (distal) stomach

– Small localized tumor

– Intestinal type histology

– No lymph node involvement

Staging Systems

Two common staging systems help guide prognosis: 

1. AJCC TNM Staging

Uses the extent of the primary Tumor, spread to nearby Nodes, and Metastasis to assign stages I through IV.

2. Japanese Classification

Has similar staging criteria but further divides stage I tumors based on depth of invasion to better distinguish early cancer prognosis after surgery. 

These systems allow clinicians to give patients estimates for 5-year survival rates based on published data. Stage I 5-year survival is around 60-90%, while stage IV survival drops to 5-20% given the systemic spread.

Beyond 5 Years 

5-year survival statistics are standard benchmarks, but lifetime outcomes vary. Approximately 65% of patients surviving 5 years remain cancer-free long-term. However recurrences after 5 years are still possible, requiring continued monitoring.

FAQ

What are the first signs of stomach cancer?

Common early signs include indigestion, heartburn, nausea, vomiting, bloating, loss of appetite, abdominal pain, fatigue and unexplained weight loss. However, these may also be caused by less serious conditions. See your doctor if symptoms persist.

How is stomach cancer diagnosed?

Diagnostic tests for stomach cancer include endoscopy with biopsy, barium swallow x-rays, CT scans, PET scans, and blood tests. These help confirm the cancer diagnosis and determine the stage.

What causes stomach cancer?

The exact cause is unknown but risk factors include age over 55, male gender, diet high in processed meats, H. pylori infection, smoking, obesity, and family history of stomach cancer.

What are the types of stomach cancer?

Adenocarcinoma (90-95% of cases) arises from stomach gland cells. Lymphoma develops from immune cells in stomach tissue. Other rare types like sarcoma and carcinoid tumors occur less frequently. 

Can stomach cancer be cured?

When detected early while still confined to the stomach lining, stomach cancer can often be cured with surgery alone for long term disease-free survival. The cure rates decrease with more advanced staged cancers.

What is the best treatment for stomach cancer?

Treatment options include surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy. The best treatment depends on the stage, location, and type of stomach cancer.

What is the survival rate for stomach cancer?

Overall 5-year survival rate is about 30%. But survival is as high as 90% when stomach cancer is diagnosed early before it has spread. Advanced cancer 5-year survival is lower at 5-20%.

How can I lower my risk of stomach cancer?

You can lower risk by treating H. pylori infection, avoiding processed meats, increasing fruits/vegetables, quitting smoking, avoiding asbestos exposure, and getting genetic counseling if you have a strong family history.

1. Stomach cancer is an aggressive disease that often spreads quickly. It ranks among the most common and deadly cancer types globally.

2. Risk factors like H. pylori infection, diet, smoking and family history play a role, but the exact cause is unknown. Early detection provides the best outcomes.

3. Adenocarcinoma arising from stomach gland cells accounts for 90-95% of stomach cancers. Lymphoma and other types are less common.

4. Multi-modal treatment typically includes surgery along with some combination of chemotherapy, radiation, or targeted therapies.

5. Prognosis varies greatly by cancer stage at diagnosis. 5-year survival ranges from 90% for early localized tumors down to 5-20% for advanced metastatic disease.

In summary, stomach cancer is a complex disease that warrants further research into improving early detection and treatment effectiveness. Public health initiatives promoting healthy lifestyles may also curb rising incidence rates. Raising awareness and outcomes will require cross-disciplinary, evidence-based approaches centered around patient wellbeing.