Stomach cancer is different from other cancers that can occur in the abdomen, like cancer of the colon or rectum (large intestine), liver, pancreas, or small intestine. These cancers can have different symptoms, different outlooks, and different treatments. The cancer’s location can also affect treatment options.

Colorectal Cancer

Colorectal cancer starts in the colon or the rectum. These cancers can also be called colon cancer or rectal cancer, depending on where they start. The stage (extent of spread) of a colorectal cancer depends on how deeply it grows into the wall and if it has spread outside the colon or rectum.

Signs and symptom

Colorectal cancer might not cause symptoms right away, but if it does, it may cause one or more of these symptoms:

  • A change in bowel habits, such as diarrhea, constipation, or narrowing of the stool, that lasts for more than a few days
  • A feeling that you need to have a bowel movement that’s not relieved by having one
  • Rectal bleeding with bright red blood
  • Blood in the stool, which might make the stool look dark brown or black
  • Cramping or abdominal (belly) pain
  • Weakness and fatigue
  • Unintended weight loss

Colorectal cancers can often bleed into the digestive tract. Sometimes the blood can be seen in the stool or make it look darker, but often the stool looks normal. But over time, the blood loss can build up and can lead to low red blood cell counts (anemia). Sometimes the first sign of colorectal cancer is a blood test showing a low red blood cell count.

Risk Factors

  • Being overweight or obese
  • Laziness or lack or physical activity
  • Certain types of diet: A diet that’s high in red meats (such as beef, pork, lamb, or liver) and processed meats (like hot dogs and some luncheon meats) raises your colorectal cancer risk.
  • Smoking
  • Alcohol use
  • If you have inflammatory bowel disease such as ulcerative colitis then your risk of colorectal cancer is increased. IBD is a condition in which the colon is inflamed over a long period of time. People who have had IBD for many years, especially if untreated, often develop cancer cells called dysplasia.
  • A family history of colorectal cancer or adenomatous polyps: People with a history of colorectal cancer in a first-degree relative (parent, sibling, or child) are at increased risk.
  • Having type 2 diabetics

Liver Cancer

A cancer that starts in the liver is called primary liver cancer. Most of the time when cancer is found in the liver it did not start there but has spread (metastasized) from somewhere else in the body, such as the pancreas, colon, stomach, breast, or lung. Because this cancer has spread from its original (primary) site, it is called a secondary liver cancer. These tumors are named and treated based on their primary site (where they started). For example, cancer that started in the lung and spread to the liver is called lung cancer with spread to the liver, not liver cancer. It is also treated as lung cancer.

Sign and Symptom 

  • Weight loss (without trying)
  • Loss of appetite
  • Feeling very full after a small meal
  • Nausea or vomiting
  • An enlarged liver, felt as fullness under the ribs on the right side
  • An enlarged spleen, felt as fullness under the ribs on the left side
  • Pain in the abdomen (belly) or near the right shoulder blade
  • Swelling or fluid build-up in the abdomen (belly)
  • Itching
  • Yellowing of the skin and eyes (jaundice)

Other symptoms can include fever, enlarged veins on the belly that can be seen through the skin, and abnormal bruising or bleeding.

Risk Factors

  • Chronic viral hepatitis:  Worldwide, the most common risk factor for liver cancer is chronic (long-term) infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). These infections lead to cirrhosis of the liver and are responsible for making liver cancer the most common cancer in many parts of the world.
  • Cirrhosis: Cirrhosis is a disease in which liver cells become damaged and are replaced by scar tissue. People with cirrhosis have an increased risk of liver cancer. Most (but not all) people who develop liver cancer already have some evidence of cirrhosis.
  • Non- alcoholic fatty liver disease: Non-alcoholic fatty liver disease is a common condition in obese people. 
  • Inherited metabolic diseases: People with hereditary hemochromatosis absorb too much iron from their food. The iron settles in tissues throughout the body, including the liver. If enough iron builds up in the liver, it can lead to cirrhosis and liver cancer.
  • Heavy alcohol use
  • Tobacco use
  • Obesity
  • Type 2 diabetics

Pancreatic Cancer

The most common type of pancreatic cancer, adenocarcinoma of the pancreas, starts when exocrine cells in the pancreas start to grow out of control. Most of the pancreas is made up of exocrine cells which form the exocrine glands and ducts. The exocrine glands make pancreatic enzymes that are released into the intestines to help you digest foods (especially fats). Endocrine cells make up a smaller percentage of the cells in the pancreas. These cells make important hormones like insulin and glucagon (which help control blood sugar levels), and release them directly into the blood. 

Exocrine cancers are by far the most common type of pancreas cancer. If you are told you have pancreatic cancer, it’s most likely an exocrine pancreatic cancer.

Sign and Symptom

  • Jaundice and related symptom: jaundice is yellowing of the eyes and skin. Most people with pancreatic cancer will have jaundice as one of their first symptoms. Yellowing of eye and skin, dark urine, light colored or greasy stool and itchy skin are both the symptom of jaundice and pancreas cancer.
  • Belly or back pain
  • Weight loss and poor appetite
  • Nausea and vomiting
  • Gallbladder or liver enlargement: Pancreatic cancer can also sometimes enlarge the liver, especially if the cancer has spread there. The doctor might be able to feel the edge of the liver below the right ribcage on an exam, or the large liver might be seen on imaging tests.
  • Blood clot: Sometimes, the first clue that someone has pancreatic cancer is a blood clot in a large vein, often in the leg. Symptoms can include pain, swelling, redness, and warmth in the affected leg. 
  • Diabetics

Risk Factors

  • Tobacco use
  • Being overweight
  • Diabetics
  • Chronic pancreatitis: Chronic pancreatitis, a long-term inflammation of the pancreas, is linked with an increased risk of pancreatic cancer.  
  • Workplace exposure to certain chemicals: Heavy exposure at work to certain chemicals used in dry cleaning and metal working industries may raise a person’s risk of pancreatic cancer.
  • Family history
  • Inherited genetic syndrome: Inherited gene changes (mutations) can be passed from parent to child. These gene changes may cause as many as 10% of pancreatic cancers. Sometimes these changes result in syndromes that include increased risks of other cancers.
  • Chronic pancreatitis: Chronic pancreatitis is sometimes due to an inherited gene mutation. People with this inherited (familial) form of pancreatitis have a high lifetime risk of pancreatic cancer.

Small Intestine Cancer

Small intestine cancer starts when cells in the small intestine start to grow out of control. The small intestine is part of the gastrointestinal (GI) tract, also known as the digestive tract. Most experts think that cancer of the small intestine develops much like colorectal cancer. It first begins as a small growth on the inner lining of the intestine, called a polyp. Over time, the polyp can change into a cancer.

Signs and symptom: The symptoms of small intestine cancers are often vague and can have other, more common causes. Unfortunately, this means that it’s often at least several months from the time symptoms start until the cancer is diagnosed.

Some of the more common symptoms of small intestine cancer are:

  • Pain in the belly (abdomen)
  • Nausea and vomiting
  • Weight loss (without trying)
  • Weakness and feeling tired (fatigue)
  • Dark-colored stools (from bleeding into the intestine)
  • Low red blood cell counts (anemia)
  • Yellowing of the skin and eyes (jaundice)

Often, the first symptom is pain in the stomach area. This pain is often crampy and may not be constant. For example, it may start or get worse after you eat.

Risk Factors

  • Smoking
  • alcohol use
  • Diet
  • Celiac disease: For people with celiac disease, eating gluten (a protein that is found in wheat and some other types of grain) causes the body’s immune system to attack the lining of the intestines. They may also have an increased risk of small intestine cancer.
  • Colon cancer: people who have had colon cancer have increased risk of getting cancer of the small intestine. This could be due to shared risk factors.
  • Inherited syndrome: People with certain inherited conditions have a higher risk of small intestine cancer.