Stomach cancer is the fifth most common cancer in the world, with roughly 970,000 new cases diagnosed in 2022. That accounts for about 4.9% of all cancers globally. How likely you are to develop it, though, depends heavily on where you live, your sex, your age, and a few modifiable risk factors.
Global and U.S. Numbers
Worldwide, stomach cancer trails only lung, breast, colorectal, and prostate cancers in frequency. Nearly a million new diagnoses each year makes it a major public health concern, but the burden is not spread evenly across the globe.
In the United States, stomach cancer is far less common. It doesn’t even rank among the top 15 cancers. The age-adjusted rate is about 9.4 new cases per 100,000 men and 5.9 per 100,000 women each year, based on SEER data from 2019 to 2023. For context, colorectal cancer hits roughly four times as many Americans annually. So while stomach cancer is a significant global disease, the average American’s individual risk is relatively low.
Where Rates Are Highest
East Asia has dramatically higher rates than the West. South Korea’s stomach cancer incidence is about 11.7 times higher than the U.S. rate. Among men, native Koreans averaged 65.4 cases per 100,000, compared to as few as 5.9 per 100,000 among Filipino Americans, the lowest-risk group studied. For women, the pattern held: 24.7 per 100,000 among native Koreans versus 2.7 per 100,000 among Filipino American women.
These differences are driven by a combination of diet, rates of a specific bacterial infection (more on that below), and screening practices. Countries like South Korea and Japan run national screening programs that catch stomach cancer earlier, which is partly why their survival outcomes are better despite the higher incidence.
Who Gets Stomach Cancer
Men are roughly 1.6 times more likely to develop stomach cancer than women. The median age at diagnosis in the U.S. is 68, so this is predominantly a disease of older adults. Most cases occur between the ages of 60 and 80.
That said, a worrying trend has emerged: rates of early-onset stomach cancer, meaning cases in people younger than 50, are rising in the United States, particularly among women. Overall U.S. stomach cancer rates have been falling for decades, but this younger subgroup is moving in the opposite direction. The reasons aren’t fully understood, though changes in diet, obesity rates, and shifting patterns of bacterial infection are all suspected contributors.
The Role of H. pylori Infection
The single biggest risk factor for stomach cancer is infection with a bacterium called H. pylori, which colonizes the stomach lining. The majority of stomach adenocarcinomas, the most common type, are attributed to this infection. H. pylori is also behind nearly all cases of a rarer form called gastric MALT lymphoma.
About half the world’s population carries H. pylori, but only a small fraction of infected people ever develop cancer. The infection causes chronic inflammation over years or decades, which in some individuals progresses through a series of changes in the stomach lining that can eventually become cancerous. H. pylori can be detected with a simple breath test or stool test and treated with a course of antibiotics, which is one reason screening in high-risk populations matters.
Other Risk Factors
Beyond H. pylori, several factors raise your risk. Diets high in salt-preserved, smoked, or pickled foods have long been linked to higher rates, which partly explains the geographic pattern in East Asia. Processed meat consumption also increases cancer risk in the digestive tract. Smoking roughly doubles the risk of stomach cancer. Heavy alcohol use, obesity, and a family history of stomach cancer all contribute as well.
A small percentage of cases are hereditary. Inherited mutations, most notably in a gene involved in cell adhesion, can cause a syndrome that leads to a diffuse type of stomach cancer at unusually young ages. If multiple close relatives have had stomach cancer, genetic counseling can help determine whether you carry one of these mutations.
Why Stage at Diagnosis Matters So Much
Stomach cancer’s prognosis varies enormously depending on how far it has spread when it’s found. The five-year survival rate for localized stomach cancer, meaning the tumor is still confined to the stomach wall, is about 75%. Once it has spread to nearby lymph nodes or organs (regional stage), that drops to 35%. For metastatic stomach cancer that has reached distant parts of the body, the five-year survival rate falls to just 7%.
The problem is that stomach cancer rarely causes obvious symptoms in its early stages. Vague discomfort, mild nausea, loss of appetite, and feeling full quickly can all be easily dismissed or attributed to something routine. By the time symptoms become hard to ignore (unintended weight loss, difficulty swallowing, vomiting, or blood in the stool), the cancer is often advanced. This is the core challenge: in countries without routine screening, most cases are caught late.
In the U.S., there is no standard screening program for stomach cancer in the general population because the overall incidence is too low to justify it. Screening is typically reserved for people at elevated risk, such as those with a strong family history, known genetic syndromes, or certain precancerous stomach conditions. In South Korea and Japan, where the disease is far more common, population-wide screening with endoscopy has meaningfully improved early detection and survival.