types of cancer

Gastrointestinal Cancer


Overview Cancers of the gastrointestinal region is a term for a group of cancers that affect the digestive system. This includes:

  • Oesophageal Cancer: Oesophageal cancer is cancer that occurs in the oesophagus — a long, hollow tube that runs from the throat to the stomach. Oesophageal cancer usually begins in the cells that line the inside of the oesophagus and can occur anywhere along the oesophagus. This cancer type is more commonly found in men in comparison to women. You can read more about oesophageal cancer here
  • Gallbladder Cancer: Gallbladder cancer, a relatively uncommon type, occurs when malignant (cancer) cells form in the tissues of the gallbladder. The gallbladder is a pear-shaped organ that lies just under the liver in the upper abdomen. It stores bile, a fluid made by the liver to digest fat. Read more about gallbladder cancer here.
  • Liver Cancer: Liver cancer, otherwise known as hepatic cancer, affects the liver. Liver cancers are malignant tumours that grow on the surface of or inside the liver. Liver cancer consists of malignant hepatic tumours (growths) in or on the liver. The most common type of liver cancer is hepatocellular carcinoma (or hepatoma or HCC). Find out more about liver cancer here.
  • Pancreatic Cancer: Pancreatic cancer is a malignant neoplasm originating from transformed cells arising in tissues forming the pancreas. The most common type of pancreatic cancer, accounting for 95% of these tumours, is adenocarcinoma (tumours exhibiting glandular architecture on light microscopy) arising within the exocrine component of the pancreas. A minority arise from islet cells, and are classified as neuroendocrine tumours. More on pancreatic cancer here.
  • Stomach Cancer: Stomach cancer or gastric cancer, refers to cancer developing in any part of the stomach. These cancers are classified according to the type of tissue they originate in. The most common type of stomach cancer is adenocarcinoma, which starts in the glandular tissue of the stomach and accounts for 90-95% of all stomach cancers. You can read more about stomach cancer here.
  • Small Intestine Cancer: Small bowel cancer is an uncommon type of cancer that occurs in the small intestine. Your small intestine, which is also called the small bowel, is a long tube that carries digested food between your stomach and your large intestine (colon).
  • Neuroendocrine Tumours: A neuroendocrine tumor begins in the hormone-producing cells of the body’s neuroendocrine system, which is made up of cells that are a combination of hormone-producing endocrine cells and nerve cells. Neuroendocrine cells are found throughout the body in organs such as the lungs and gastrointestinal tract, including the stomach and intestines.
  • Colorectal Cancer: Colorectal cancer is a cancer that starts in the colon or the rectum. These cancers can also be named colon cancer or rectal cancer, depending on where they start. Colon cancer and rectal cancer are often grouped together because they have many features in common. Read more about colorectal cancer here.
  • Anal Cancer: Anal cancer is an uncommon type of cancer that occurs in the anal canal. The anal canal is a short tube at the end of your rectum through which stool leaves your body. Anal cancer is very different from colorectal cancer, which is much more common. Anal cancer, though rare, is a lump created by the abnormal and uncontrolled growth of cells in the anus. Find out more about anal cancer here.
  • Gastro-intestinal Stromal Tumour: Gastrointestinal stromal tumors (GISTs) may be malignant (cancer) or benign (not cancer). Commonly found in the stomach and small intestine but may be also found in other parts near or inside the GI tract. Scientists believe that GISTs begin in cells called interstitial cells of Cajal (ICC), in the wall of the GI tract.
  • The symptoms that manifest are related to the organ affected. GI cancer can be diagnosed through an endoscopy, followed by biopsy of suspicious tissue. The treatment depends on the location of the tumour, as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere in the body.


    Since the cancer of a number of organs of the digestive system is clubbed under Gastrointestinal Cancer, the symptoms may vary. Some of the common symptoms may include the following:

  • Abdominal pain, tenderness or discomfort
  • Change in bowel habits, such as frequency or consistency or shape
  • Rectal bleeding or blood in stool
  • Bloated feeling after eating, even when eating a small amount
  • Loss of appetite
  • Nausea/vomiting
  • Unintentional weight loss
  • Fatigue
  • These are common symptoms of gastrointestinal cancer, but there are more symptoms that relate specifically to each type.


    The following are considered to be the causes or the risk factors that could lead to the various gastrointestinal cancers:

  • Smoking
  • Excessive alcohol consumption
  • Increasing age
  • Diet high in animal fat
  • Diet containing high amounts of salted, cured, or poorly preserved foods
  • Chronic pancreatitis
  • Obesity
  • Family history of GI cancer
  • Diagnosis

    The detection and confirmation of gastrointestinal cancers are done through various and following are the key diagnostic modalities.

    Physical exam and history: An examination of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.

    Blood chemistry studies: This is a procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it.

    Complete Blood Count (CBC): A procedure in which a sample of blood is drawn and checked for the following:

  • The number of red blood cells, white blood cells and platelets
  • The amount of haemoglobin (the protein that carries oxygen) in the red blood cells
  • The portion of the sample made up of red blood cells
  • CAT scan: In this procedure, a series of detailed pictures of areas inside the body are taken from different angles. The pictures are made by a computer linked to an X-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called Computed Tomography, Computerised Tomography or Computerised Axial Tomography.

    Biopsy: The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. A biopsy of the stomach is usually done during the endoscopy.


    Some gastrointestinal cancer cases are treated with a single treatment modality or with a combination of two or more. The suitable treatment option for each case is decided based on various parameters such as the type of cancer, location and size, the stage of the cancer, patient’s age and the overall condition of the patient. Below are some of the major treatment modalities:

    Surgery: When used to treat cancer, surgery is a procedure in which a surgeon removes cancer from the body. It could be non-invasive, minimally-invasive or open surgery depending on the factors mentioned above. The surgery is often preceded or succeeded by chemotherapy.

    Radiation therapy: Radiation therapy is a type of cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumours. Radiation can either be delivered externally or internally. Radiation therapy is always used in combination with the surgery or chemotherapy for enhanced efficacy.

    Chemotherapy: Chemotherapy is a type of cancer treatment that uses drugs to kill cancer cells. Chemotherapy is used along with radiation therapy and surgery. Chemotherapy is usually prescribed in the following cases:

  • Along with radiotherapy as an alternative to surgery (called chemoradiation)
  • After surgery to decrease the risk of the relapse
  • To slow the growth of a tumour and control symptoms when the cancer cannot be completely treated (palliative treatment)
  • Immunotherapy: Immunotherapy boosts the body’s immune system to fight against cancer. Once the immunity is boosted, the body detects and destroys the cancer cells throughout the body. Although not as popular as chemotherapy or radiotherapy, immunotherapy is used to treat a few types of cancers.

    Targeted therapy: Targeted therapy is a type of cancer treatment that targets biomolecules that control how cancer cells grow, divide, and spread. By targeting these biomolecules, this treatment modality may promote stronger immunity, stop cancer cells from growing, deliver tumour-killing molecules to the cancer, cut-off nutrient supply to the tumour cells or kill the cancer cells.

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