The pancreas is one of the vital glandular organs of the body located in the abdomen horizontally behind the stomach. Being an endocrine gland, it secretes very important hormones like insulin, glucagon, and a pancreatic polypeptide which control the metabolism of sugar. It also secretes several digestive enzymes through pancreatic juices that help in the digestion process.
Pancreatic cancer is the cancer of the pancreatic tissue and is of major concern as it grows and spreads very rapidly and has a poor prognosis even if it is detected early. It rarely produces any symptoms in its early stage. The signs and symptoms always appear when the cancer is in the advanced stage and the symptoms may include pain in the upper abdomen that often radiates to back, loss of weight and appetite, yellowish discolouration of the skin and eyes, blood clots and associated depression.
The exact cause of pancreatic cancer is not known but there are some factors that increase your risk of developing pancreatic cancer. These include:
- Advancing age
- Obesity or excessive body weight
- Chronic inflammation of the pancreas
- Race- common in Africans and Americans
- Genetic inheritance
- A family history of some genetic problems like BRCA2 gene mutation, FAMMM (familial atypical mole-malignant melanoma) or Lynch syndrome
- A family history of pancreatic cancer
- Diabetes and smoking
Tests and procedures to detect, diagnose, and stage pancreatic cancer are usually done at the same time in single procedure. In order to plan treatment, it is important to know the stage of the disease and whether pancreatic cancer can be removed by surgery or not.
The following tests and procedures may be used:
- Physical exam and history: An physical observation 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 in this.
- Blood chemistry studies: In this procedure, blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues of the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
- Tumor marker test:In this procedure , sample of blood, urine, or tissue is checked to measure the amounts of certain substances, such as CA 19-9, and carcinoembryonic antigen (CEA), made by organs, tissues, or tumor cells in the body. Certain substances are linked to specific types of cancer when found in increased levels in the body. These are called tumor markers.
- MRI (magnetic resonance imaging): This procedure uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- CT scan (CAT scan): In this procedure a series of detailed pictures of areas inside the body, 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, computerized tomography, or computerized axial tomography. A spiral or helical CT scan makes a series of very detailed pictures of areas inside the body using an x-ray machine that scans the body in a spiral path.
- PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do. A PET scan and CT scan may be done at the same time. This is called a PET-CT.
- Abdominal ultrasound: An ultrasound exam used to make pictures of the inside of the abdomen. The ultrasound transducer is pressed against the skin of the abdomen and directs high-energy sound waves (ultrasound) into the abdomen. The sound waves bounce off the internal tissues and organs and make echoes. The transducer receives the echoes and sends them to a computer, which uses the echoes to make pictures called sonograms. The picture can be printed to be looked at later.
- Endoscopic ultrasound (EUS): A procedure in which an endoscope is inserted into the body, usually through the mouth or rectum. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography.
- Endoscopic retrograde cholangiopancreatography (ERCP): A procedure used to x-ray the ducts(tubes) that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. Sometimes pancreatic cancer causes these ducts to narrow and block or slow the flow of bile, causing jaundice. An endoscope (a thin, lighted tube) is passed through the mouth, oesophagus, and stomach into the first part of the small intestine. A catheter (a smaller tube) is then inserted through the endoscope into the pancreatic ducts. A dye is injected through the catheter into the ducts and an x-ray is taken. If the ducts are blocked by a tumor, a fine tube may be inserted into the duct to unblock it. This tube (or stent) may be left in place to keep the duct open. Tissue samples may also be taken.
- Percutaneous transhepatic cholangiography (PTC): A procedure used to x-ray the liver and bile ducts. A thin needle is inserted through the skin below the ribs and into the liver. Dye is injected into the liver or bile ducts and an x-ray is taken. If a blockage is found, a thin, flexible tube called a stent is sometimes left in the liver to drain bile into the small intestine or a collection bag outside the body. This test is done only if ERCP cannot be done.
- Laparoscopy: A surgical procedure to look at the organs inside the abdomen to check for signs of disease. Small incisions (cuts) are made in the wall of the abdomen and a laparoscope (a thin, lighted tube) is inserted into one of the incisions. The laparoscope may have an ultrasound probe at the end in order to bounce high-energy sound waves off internal organs, such as the pancreas. This is called a laparoscopic ultrasound. Other instruments may be inserted through the same or other incisions to perform procedures such as taking tissue samples from the pancreas or a sample of fluid from the abdomen to check for cancer.
- Biopsy: This involves removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. There are several procedures to do a biopsy for pancreatic cancer . During this procedure a fine needle or a core needle may be inserted into the pancreas during an x-ray or ultrasound to remove cells. Tissue may also be removed during laparoscopy or surgery to remove the tumor.
Stages of Pancreatic cancer
Pancreatic cancer can be staged as;
Stage I: cancer is confined to the pancreas. This stage is subdivided into 2;
- Stage IA: In this stage, cancer is limited to the pancreas and tumour is smaller than 2 cm and has not spread to lymph nodes or other parts.
- Stage IB: In this stage, cancer confined to pancreas but larger than 2 cm and has not spread to lymph nodes or other body parts.
Stage II: divided into 2 substages
- Stage IIA: cancer has started growing to the nearby tissue like duodenum or biliary duct but is limited to large blood vessels
- Stage IIB: cancer of variant size has grown into the surrounding tissues and it is also found in the adjacent lymph node but not in the blood vessels.
Stage III: cancer is invading outside the pancreas into the blood vessels but may or may not have spread to the lymph nodes and other areas in the body
Stage IV: cancer has spread to other parts of the body most often affecting the liver or lungs.
Following are the options to treat the cancer of the pancreas:
It is symbolized when the cancer is confined to the pancreas. This includes surgery of either the head or tail of the pancreas depending on where the tumour is present in pancreas. Different types of surgery are:
- Pancreatoduodenectomy: commonly known as the Whipple procedure, it is done when the cancer is located in the head of the pancreas. This procedure includes excision of the head of the pancreas with a small portion of the duodenum (part of small intestine), gall bladder and some part of the biliary duct. The residual parts are then reconnected to allow proper digestion of food.
- Distal pancreatectomy: this is performed to remove the tail of the pancreas along with a small portion of the body of the pancreas. The spleen may or may not be removed depending on the extent of disease. These procedures can be done either through a traditional method in which the single incision is made to perform the surgery or the minimally invasive (laparoscopic) approach is used to lessen the risk and complication which are common in the traditional approach.
Radiation therapy :
Radiation therapy involves the use of high powered energy beam to kill cancerous cells. A patient may need radiation therapy either before or after the surgery or in combination with the chemotherapy. The radiation can be delivered using;
- External beam radiation therapy: the machine that emits radiation beam moves around the patient targeting the specific area of the body.
- Intraoperative radiation: radiation therapy is used as a part of surgery or given during the surgery.
Involves using one or a combination of drugs that may be injected or taken orally that helps in killing the cancer cells. If the cancer is not confined to the pancreas and has spread to nearby organs, then chemotherapy is combined with the radiation therapy often called chemoradiation is used to treat cancer.
Targeted drug therapy:
Involves the use of drugs that restrict the substances that provoke the cancer cell to divide and grow. One of the drug is Erlotinib , if combined with the chemotherapy, can be used to treat more advanced cases of pancreatic cancer.
Also known as biological therapy. It entails using the patient’s own body’s immune system to fight cancer. Some of the patient’s own immune cells are taken and genetically modified in the lab and are injected back in the body to fight the cancer cells. Biological agents like monoclonal antibodies, therapeutic vaccines, checkpoint inhibitors, immune modulators, adoptive T cell and cytokines are used as the special immune system cells to stimulate the body’s immune system , this destroy and kill the cancerous cells.