Age Range and Risk Factors for Stomach Cancer

About 6 out of 10 people diagnosed with stomach cancer are over the age of 65. The average age of diagnosis is 68.

Roughly 2% to 8% of stomach cancers are diagnosed in people under 40.

According to data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results program, the rates of stomach cancer per 100,000 people in 2019 were:

Many people incorrectly believe that stomach cancer only affects older people and ignore the early warning signs. Delaying diagnosis gives the cancer a chance to spread and makes it more difficult to treat.

The number of people being diagnosed with stomach cancer each year in the United States is decreasing. However, the percentage of stomach cancers in younger people (called early onset gastric cancer) has been steadily rising. It now makes up more than 30% of stomach cancers in the United States.

The number of stomach cancers in young adults has decreased in most countries, but rates in the United States in people under 40 have remained stable or increased slightly.

It’s not clear why this is occurring, but factors such as increasing obesity rates and lifestyle factors may be contributing. Rates of colorectal cancer in people under 50 are also increasing and have nearly doubled since the early 1990s.

In a 2018 study, researchers analyzed cancer registration data covering 80% of the population of the United States. They found decreasing rates of a type of lower stomach cancer called noncardia stomach cancer in older adults but increasing rates in people under 50. The most drastic increase was seen in non-Hispanic white women.

Noncardia stomach cancer is primarily caused by Helicobacter pylori infection and autoimmune gastritis. The researchers speculated that increased use of antibiotics in recent years may be linked to increased rates of autoimmune gastritis, and this might be contributing to increased rates of noncardia stomach cancer.

Researchers have identified the following risk factors for developing stomach cancer:

• Age: Most people are over 60 when they’re diagnosed with stomach cancer and about 60% of people are over the age of 65.
• Sex: Men are about twice as likely as women to develop stomach cancer.
• H. pylori infection: H. Pylori is a bacteria that’s thought to live in the stomach of more than 44% of the world’s population. Infection with H. pylori is thought to be one of the main risk factors for stomach cancer.
• Ethnicity: In the United States, stomach cancer is mostly diagnosed in:
  • African Americans
  • Hispanic Americans
  • Native Americans
  • Asian and Pacific Islanders
• Diet: Eating a high-salt diet has been linked to an increased risk of stomach cancer. Eating fruits and vegetables may lower the risk.
• Previous health condition: Some previous health conditions may increase your risk of stomach cancer such as:
  • previous stomach surgery
  • vitamin B12 deficiency
  • low stomach acid (achlorhydria)
  • some type of stomach polyps
• Occupational exposure: Exposure to certain types of dust and fumes may increase your risk of stomach cancer. People at increased risk may include:
  • miners and quarry workers
  • well-drillers
  • blacksmiths
  • toolmakers
  • carpenters
  • construction workers
• Tobacco and alcohol: People who smoke have about double the risk of stomach cancer as non-smokers. Researchers have also identified a link with alcohol consumption, especially in people who consume three drinks or more per day.
• Obesity: Obesity has been linked to an increased risk of stomach cancer in men, but it’s unknown if it increases the risk in women.
• Family history: People with a sibling or parent with stomach cancer are at an increased risk of developing it too. Some cancer syndromes such as hereditary diffuse gastric cancer are passed through families.
• Common variable immune deficiency: People with common variable immune deficiency are more likely to develop lymphoma and stomach cancer.
• Type A blood: According to the American Cancer Society, people with type A blood develop stomach cancer more often for unknown reasons.

According to the American Cancer Society, stomach cancer rarely causes symptoms in the early stages. Most stomach cancers aren’t found until they’ve grown large or spread to other body parts.

Symptoms are often general and can have many other potential causes. They may include:

• blood in your stool
• loss of appetite
• unintentional weight loss
• abdominal pain, often above your belly button
• heartburn or indigestion
• nausea or vomiting
• swollen belly
• fatigue
• jaundice

How is stomach cancer diagnosed?

The most common test used to diagnose stomach cancer is called an endoscopy. It involves putting a long tube down your throat with a tiny camera that allows doctors to see the inside of your stomach. Doctors can take a small tissue sample with tools on the endoscope to confirm a cancer diagnosis after lab analysis.

How is stomach cancer treated?

The primary treatments for stomach cancer are:

• surgery
• chemotherapy
• targeted therapy
• immunotherapy
• radiation therapy

Is stomach cancer curable?

Stomach cancer caught in the early stages may be curable, but it becomes harder to treat the farther it spreads. The 5-year relative survival rate of stomach cancer contained to the stomach is 70%, but it drops to 6% if it spreads to distant organs.

What is the most common type of stomach cancer?

About 90% to 95% of stomach cancers are adenocarcinomas. These cancers develop in cells that produce mucus in your stomach’s inner lining.

Stomach cancer most often develops in people over the age of 60. The average age at the time of diagnosis is about 68. Some of the main risk factors include H. pylori infection, male sex, and eating a high-salt diet.

The overall rate of stomach cancer in the United States is going down, but the percentage of stomach cancers in young people has been increasing. It’s not clear why this is happening, but factors such as increasing obesity rates, dietary factors, and increased use of antibiotics may be playing a role.