Stomach Gastric Cancer

Stomach (gastric) cancer begins when abnormal cells in the stomach lining grow and divide in an uncontrolled way. Because every patient’s situation is unique, our team at Illinois CancerCare focuses on early detection, accurate diagnosis, and personalized treatment plans designed to give you the best possible outcome. Most stomach cancers in the U.S. are adenocarcinomas that arise from the inner lining (mucosa) of the stomach.

Understanding the Stomach

The stomach is a J-shaped organ in the upper abdomen that mixes food with digestive juices and passes partially digested food into the small intestine. The stomach wall has several layers; gastric cancers usually start in the mucosa and can grow outward through deeper layers over time.

Types of Stomach Cancer

Adenocarcinoma

≈90–95% of cases) — includes cardia (upper) and noncardia (distal) tumors and may be described as intestinal or diffuse type based on cell appearance.

Gastrointestinal stromal tumor (GIST), lymphoma, and neuroendocrine tumors

less common stomach cancers treated differently than typical adenocarcinoma.

Signs & Symptoms

Early stomach cancer may cause no symptoms. As it progresses, symptoms can include:

Indigestion, heartburn, or persistent stomach discomfort/pain
Early satiety (feeling full after small amounts), bloating, nausea, or vomiting
Unintentional weight loss or fatigue
Difficulty swallowing (when tumors involve the upper stomach/GE junction)

These symptoms can be caused by many conditions, but persistent or worsening symptoms should be evaluated.

Risk Factors

Helicobacter pylori (H. pylori) infection
Older age and male sex
Smoking; heavy salt/smoked/preserved foods; low fruit/vegetable intake
Chronic gastritis, intestinal metaplasia, pernicious anemia, gastric adenomatous polyps
Family history and certain inherited syndromes (e.g., hereditary diffuse gastric cancer), for which genetic counseling/testing may be appropriate

Talk with your care team about your personal risk and whether additional evaluation is warranted.

Prevention

Treat H. pylori when present and follow clinician guidance for surveillance of precancerous stomach changes.
Avoid tobacco, limit alcohol, maintain a healthy weight, and emphasize fruits/vegetables while limiting salted/smoked/preserved foods.

Screening

There is no standard screening test for average-risk people in the U.S. Screening may be considered for high-risk groups (e.g., certain hereditary syndromes or significant precancerous lesions) and typically involves upper endoscopy.

Diagnosis

When stomach cancer is suspected, your Illinois CancerCare team may use:

the primary test to confirm diagnosis and assess tumor location/extent.

evaluates depth of invasion and nearby lymph nodes.

assesses spread to lymph nodes or distant organs.

and, in select cases, diagnostic laparoscopy to evaluate the abdominal cavity (peritoneum) before treatment.

Your pathology report will describe the histology, tumor location (cardia vs noncardia), and may include biomarker testing (e.g., HER2, PDL1, MSI/dMMR) that can influence treatment decisions in advanced disease.

Staging

Stomach cancer is staged using TNM (tumor depth, lymph node involvement, and metastasis) to group tumors from Stage 0 (carcinoma in situ) through Stage IV (metastatic); stage helps guide treatment and prognosis.

Treatment Options

Treatment is individualized based on stage, tumor location, pathology, biomarkers, overall health, and your goals. Care is coordinated by a multidisciplinary team.

Very Early Cancers / High-Grade Dysplasia

Endoscopic mucosal resection (EMR)/endoscopic submucosal dissection (ESD) to remove lesions confined to the inner lining, when criteria are met.

Localized/Resectable Disease

Surgery (subtotal or total gastrectomy with lymph node removal) is a key component of cure. Perioperative (before/after surgery) chemotherapy or chemoradiation may be used to increase cure rates, depending on stage and location.

Locally Advanced/Borderline-Resectable

Neoadjuvant (pre‑operative) chemotherapy ± chemoradiation to shrink tumors and improve surgical outcomes, followed by gastrectomy when feasible.

Advanced/Metastatic or Unresectable

Systemic therapy options include chemotherapy, targeted therapy (e.g., HER2‑directed agents for HER2‑positive disease), and immunotherapy in biomarker‑selected settings (e.g., MSI‑H/dMMR, PD‑L1 positive). Palliative procedures (stents, radiation, or surgery) may help relieve symptoms and improve quality of life.

Your Illinois CancerCare team will review benefits/risks of each option and discuss whether a clinical trial may be appropriate for you.

Prognosis

Prognosis depends on stage at diagnosis, tumor biology, response to therapy, and overall health. While stomach cancer is less common in the U.S. than in many regions worldwide, early detection and modern multimodality treatments have improved outcomes; your doctor will explain what your individual features mean.

Follow-Up Care

After treatment, follow-up often includes:

Regular clinic visits, nutritional counseling, and symptom review
Imaging and/or endoscopic assessments when indicated
Surveillance for treatment effects, including vitamin/mineral deficiencies after gastrectomy

Your plan will be tailored to your diagnosis and treatment.

Living With Stomach Cancer

Illinois CancerCare offers comprehensive support, including counseling, nutrition services (important for appetite, weight, and digestion during/after treatment), survivorship programs, caregiver resources, and access to clinical trials close to home. ACS and national stomach-cancer organizations provide additional education, navigation, and peer support.

Why Choose Illinois CancerCare

Experienced multidisciplinary team in GI oncology
Advanced diagnostics and timely, coordinated care
Access to innovative treatments and clinical trials
Compassionate, patient-centered care focused on your goals and quality of life

Sources & Patient Friendly References

All information was taken from the NCI (National Cancer Institute) and ACS (American Cancer Society).