Diagnosis and Treatment, Featured, Prevention and Screening, Stomach Cancer

As stomach cancer rates rise in younger people, knowing symptoms and family history is key

By Nicole Ferrara • February 11, 2025

Estimated reading time: 6 minutes

By Jessica Saenz

Stomach cancer rates in the United States have been steadily decreasing for decades, but recent trends reveal an increase in early-onset stomach cancer in people younger than 50, particularly women. Trends also reveal younger people have more advanced stomach cancer at the time of diagnosis.

While cancer experts don't yet fully understand why younger people are getting stomach cancer, they know that early diagnosis saves lives. Mojun Zhu, M.D., a Mayo Clinic medical oncologist who specializes in gastrointestinal cancers, says knowing your family history and the symptoms of stomach cancer can help you get diagnosed before the disease has spread. She notes early treatment is most likely to be successful.

Dr. Zhu explains what you should know:

Stomach cancer symptoms can be vague.

Stomach cancer doesn't always cause symptoms in the early stages. When it does, symptoms are vague, and people often treat them with over-the-counter medications or dismiss them.

"The symptoms are not clear-cut, and they overlap with many other benign conditions," says Dr. Zhu. "A lot of our younger patients attribute their symptoms to indigestion or reflux, so they don't follow up or seek medical care immediately."

This delay allows stomach cancer to advance to later stages that are more difficult to treat.

Advanced stomach cancer may cause symptoms such as fatigue, unexplained weight loss, appetite loss, feeling full after eating a small amount of food, anemia, vomiting blood and black stools. Dr. Zhu says these symptoms often prompt her patients to seek medical care. "When people feel their symptoms are not getting better — they've started losing weight, struggling with eating and swallowing — that's when they come to see us."

A family history of cancer might indicate increased stomach cancer risk.

There are no screening recommendations for people at average risk of stomach cancer, but if you have symptoms that align with stomach cancer and a family history of cancer, your healthcare professional might recommend additional screening or genetic testing.

"It's really important to know your first-degree family's history — that's parents, siblings and children — and second-degree family, such as your grandparents, uncles and aunts," says Dr. Zhu. "If you have heard about first- or second-degree family members having breast, stomach, or other types of gastrointestinal cancers before age 50, discuss that with your primary care professionals to see if you should consider more advanced genetic testing or genetic counseling."

If genetic test results indicate you carry an inherited condition that increases your risk of stomach cancer, your healthcare professional may recommend a screening plan tailored to your risk.

Screening for stomach cancer in the U.S. is often done through an upper endoscopy, a procedure where a thin tube with a camera is inserted through the mouth and down the throat into the stomach.

Genetic conditions that increase your risk of stomach cancer include Lynch syndrome, juvenile polyposis syndrome, Peutz-Jeghers syndrome, familial adenomatous polyposis and hereditary diffuse gastric cancer.

Hereditary diffuse gastric cancer is an inherited syndrome caused by a mutation in the CDH1 gene that increases the risk of stomach and breast cancer. "For patients with this syndrome, we recommend early screening — usually beginning in their 20s — for stomach and breast cancer," says Dr. Zhu.

Stomach cancer can be difficult to treat, but therapies are improving.

Though stomach cancer is less common than other cancers, it can be more aggressive, has higher mortality rates, and often recurs. In earlier stages, when stomach cancer is localized, meaning it hasn't spread to other organs or lymph nodes, treatment may be more successful. "If you have stage 1 stomach cancer, it can usually be cured by surgery," says Dr. Zhu. "When you have stage 2 or 3 stomach cancer, despite surgery and chemotherapy, the risk of recurrence can be as high as or greater than 50%. Even though we consider localized stomach cancer to be a curable condition, the risk of having relapse is high."

Dr. Zhu says cancer researchers are making progress in stomach cancer treatment for all stages.

Early-stage stomach cancer

Mayo Clinic cancer researchers are investigating how and why stomach cancer develops and trying to find ways to detect it early in people with high risk. "Our colleagues in Gastroenterology are researching ways to help identify early-stage stomach cancer. This includes upcoming clinical trials to investigate the effectiveness of MRI as a screening test for people at high risk of stomach cancer," she says.

Dr. Zhu adds that researchers are also advancing minimally invasive surgical techniques to improve quality of life for people with early-stage stomach cancer. "Locoregional therapies such as endoscopic mucosal resection may help people with very early-stage stomach cancer avoid a full or partial gastrectomy (removal of all or part of the stomach)," she says.

Similar to an upper endoscopy, an endoscopic resection passes a long narrow tube called an endoscope down the throat and into the stomach. The endoscope can be used to identify and remove abnormal or cancerous tissue.

Advanced stomach cancer

Dr. Zhu says Mayo Clinic is researching new therapies for advanced stomach cancer in clinical trials. These include immunotherapy, which leverages your immune system to attack cancer cells, and targeted drug therapies, which target certain aspects of cancer cells that help them grow, divide and spread.

"There are newer classes of medications called antibody drug conjugates and bispecific antibodies that have demonstrated promising results in early-phase clinical trials," she says. Antibody drug conjugates attach a cancer-killing drug to an antibody that targets cancer cells, delivering the drug directly to cancer cells to minimize damage to healthy cells. Bispecific antibody drugs bind to cancer cells and immune cells, bringing them together so the immune cells can attack and destroy the cancer cells.

In late 2024, the FDA also approved the use of a new monoclonal antibody drug that uses a lab-made protein that binds to a specific target on a cancer cell to help the immune system identify and attack it. This drug can be used in combination with first-line chemotherapy in patients with certain advanced stomach cancers that cannot be surgically removed, have spread to other parts of the body, and are HER2-negative.

Hyperthermic intraperitoneal chemotherapy (HIPEC), a heated liquid form of chemotherapy, is also an option for some people with advanced stomach cancer. It can be used in combination with surgery to kill any remaining cancer cells left behind in the abdominal cavity after tumor removal. Recent studies have shown this drug combination is extending the lives of people with stage 4 gastric cancers that have spread in the abdominal cavity.

Stomach cancer spread and related cancer development

People with stomach cancer have a high risk of developing peritoneal carcinomatosis, a metastatic disease that occurs when cancer spreads and grows in the membrane that drapes over the organs in the abdomen and pelvis. "Up to 50% of stomach cancer patients develop peritoneal disease down the road despite having a total gastrectomy. Our surgeons are developing clinical trials to look at the use of intraperitoneal therapy (treatment placed directly in the abdominal cavity) to lower the risk," says Dr. Zhu.

Though there are still many unanswered questions about the increasing incidence of stomach cancer in younger people, knowing your family history and stomach cancer symptoms can help you catch the disease early when it's most treatable. If you have new symptoms associated with stomach cancer, don't delay — talk to your healthcare professional. Ask if screening or genetic testing is right for you.