Pancreatic Cancer

Pancreas

Pancreas is a long, flat, pear shaped glandular organ that lies in the abdomen. The pancreas consists of exocrine and endocrine glands which secrete pancreatic juices, hormones, and insulin.

Endocrine gland is responsible for the secretion of the hormones insulin and glucagon that controls our blood sugar level.
Exocrine gland secret pancreatic juices that are released into the intestine by pancreatic ducts in order to help digest fat, proteins, and carbohydrates.

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Functions

It serves as two glands in one: a digestive exocrine gland and a hormone-producing endocrine gland.
The pancreas secretes enzymes to break down the proteins, lipids, carbohydrates, and nucleic acids in food.
The pancreas secretes the hormones insulin and glucagon to control blood sugar levels.

Pancreatic Cancer:

Cancer is a class of disease characterized by mutated cell growth in an uncontrolled way. Pancreatic cancer occurs when this uncontrolled cell growth begins in any part of the pancreas. Rather than developing into normal, healthy pancreas tissue, these abnormal cells continue dividing and form lumps or masses of tissue called tumours. Tumours then interfere with the main functions of the pancreas.

If a tumour stays in one spot and demonstrates limited growth, then it is considered to be benign. The tumor which sheds cells that migrate to different parts of the body is called a malignant tumor.

When a tumour successfully spreads to other parts of the body and grows, invading and destroying other healthy tissues, it is said to have metastasized. This process itself is called metastasis, and the result is a more serious condition that is very difficult to treat.

Types of Pancreatic Cancer:

Pancreatic Cancer is classified into two types, based on the part of pancreas that is affected –

Exocrine tumors: Most tumours affecting the exocrine gland are called adenocarcinomas. This type of cancer forms in the pancreas ducts and treatment for these tumours is based on stage of growth. About 95 % of Pancreatic Cancers begin in the exocrine cells of the pancreas.
Other less common types of exocrine tumors are :
- Adenosquamous carcinoma
- Squamous cell carcinoma
- Giant cell carcinoma
- Acinar cell carcinoma
- Small cell carcinoma

Endocrine tumors : These tumors are less common and are most often benign. Though rare, cancer stemming from a pancreatic endocrine tumor (PET) affects the hormone-producing cells. These tumors are also called islet cell tumours or neurendocrine tumours.
Endocrine Pancreatic Cancers are uncommon, and are named according to the type of hormone produced:
- Insulinomas
- Glucagonomas
- Somatostatinomas
- Gastrinomas
- VIPomas
- Non-secreting islet tumors.

Occurrence Rate of Pancreatic Cancer

Pancreatic Cancer is more common in western countries as compared to developing countries like India. However, data from recent studies and surveys have revealed that there is an alarming rise in Pancreatic Cancer cases.

The one year survival rate for this rare and aggressive form of cancer is about 20% and 5 year survival rate declines to 7%. Though the 5 year survival rate is low, it can rise upto 20% – 35%, if the tumor is detected at early stage (before metasizing) and is removed completely.

Pancreatic Cancer is aggressive with few symptoms until the cancer is advanced. In the early stages, the cancer doesn’t usually show any signs or symptoms. By the time the symptoms are visible, the cancer has already spread beyond the pancreas.

Jaundice and related symptoms
- Dark urine
- Light-coloured stools
- Itchy skin
Abdominal or back pain
Loss of appetite, nausea, and vomiting
Digestive problems
- Pale, greasy stools
- Nausea and vomiting
Gallbladder enlargement
Blood clots
Fatty tissue abnormalities
Diabetes

These symptoms of Pancreatic Cancer have numerous other causes, making it difficult to diagnose the disease before it is in an advanced stage.

Cancer is the result of cells that grows uncontrollably and do not die naturally. Normal cells in the body follow an orderly path of growth, division, and death. Programmed cell death is called apoptosis, and when this process breaks down, it results into cancer.

Pancreatic Cancer cells do not experience programmatic death, but instead continue to grow and divide. Although scientists do not know exactly what causes these cells to behave this way, they have identified several potential risk factors. Some of the causes are discussed below:

DNA Cells

DNA cells may sometime experience uncontrolled growth due to mutations in the DNA, and damage the genes involved in cell division. Four key types of genes are responsible for the cell division process:

Oncogenes tell cells when to divide,
Tumour suppressor genes tell cells when not to divide,
Suicide genes control apoptosis and tell cells to kill themselves if something goes wrong,
DNA-repair genes instruct cells to repair damaged DNA.

Cancer occurs when a cell’s gene mutations results in permanent DNA damage. DNA mutations that lead to Pancreatic Cancer are mostly a resultant of factors that affected DNA after birth rather than a merely inheritance from parents.

Genes – the family type

Pancreatic Cancer can be the result of a genetic predisposition inherited from family members. About 10% of Pancreatic Cancers are caused by inherited gene mutations. Genetic syndromes that are associated with Pancreatic Cancer include hereditary breast and ovarian cancer syndrome, melanoma, pancreatitis, and non-polyposis colorectal cancer (Lynch syndrome).

Carcinogens

Carcinogens are a class of substances that are directly responsible for damaging DNA, promoting or aiding cancer. Certain pesticides, dyes, and chemicals used in metal refining are thought to be carcinogenic, increasing the risk of developing Pancreatic Cancer.

When our bodies are exposed to carcinogens, free radicals are formed that try to steal electrons from other molecules in the body. These free radicals damage cells, affecting their ability to function normally, and the result can be cancerous growths.

Other lifestyle factors that might lead to Pancreatic Cancer are:

Tobacco use: The risk of getting Pancreatic Cancer increases with the use of tobacco. It is twice as high among smokers compared to those who have never smoked. The good thing is that it is a controllable factor and one can choose to avoid it.

Overweight and obesity: Obese people are about 20% more likely to develop Pancreatic Cancer. Extra weight around the waistline may be a risk factor. People who exercise regularly have about half the risk of Pancreatic Cancer as sedentary people do.

Workplace exposure to certain chemicals : Heavy exposure at work to certain pesticides, dyes, and chemicals used in metal refining may increase the risk of developing Pancreatic Cancer.

Age : Most of the patients reported for Pancreatic Cancer are above 45 years of age.

Gender : Men are about 30% more likely to develop Pancreatic Cancer than women.

Diabetes : Pancreatic Cancer is more common in people who have diabetes. In some people, though, the cancer seems to have caused the diabetes. This can happen when cancer spreads through the pancreas and damages enough of the insulin-making cells to cause diabetes.

Chronic pancreatitis : This condition is linked with an increased risk of Pancreatic Cancer, but most people with pancreatitis never develop Pancreatic Cancer.

Stomach problems : Infection of the stomach with the ulcer-causing bacteria Helicobacter pylori (H. pylori) may increase the risk of getting Pancreatic Cancer.

The best way to lower the risk of Pancreatic Cancer is to avoid risk factors and get an early diagnosis, with regard to natural factors. Some of the lifestyle changes mentioned below do offer some shielding to the disease:

Exercising and maintaining healthy weight.
Staying away from tobacco, smoking and alcohol.
Controlling diabetes.
Ensuring workplace safety.

The “stage of cancer” is a term used to describe the spread and extent of the Cancer cells. During diagnosis, a stage is assigned to the cancer to facilitate planning and proper treatment of the disease. The stages of Pancreatic Cancer are categorized as follows:

Stage 0 (Tis, N0, M0):

Pancreatic Cancer is limited to a single layer of cells in the pancreas. The Pancreatic Cancer is not visible on imaging tests.

Stage I(T1/T2, N0, M0)

Pancreatic Cancer is limited to the pancreas, but has grown to less than 2 centimeters across (stage IA) or greater than 2 centimeters (stage IB). It has not spread to lymph nodes or other parts of the body.

Stage II (T1, T2, or T3; N0/N1; M0)

A tumor of any size may have extended beyond the pancreas, but the tumor has not spread to nearby arteries or veins. It has not spread to any lymph nodes or other parts of the body.

Stage III (T4, N1, M0):

A tumor has spread to nearby arteries, veins, and/or lymph nodes but has not spread to other parts of the body.

Stage IV (any T, any N, M1):

Any tumor that has spread to other parts of the body.

Survival rate is a calculation of the probability of surviving the disease based on the earlier track records of a number of patients having the same disease at the same stage. Since, the prognosis and treatment of each individual may vary based on a number of other factors like health history, immunity, family history etc., so predicting the outcome of any particular case to precision is not possible.

Exocrine Pancreatic Cancer

Stage	5 year Survival Rate
Stage IA	14%
Stage IB	12%
StageIIA	7%
Stage IIB	5%
Stage III	3%
Stage IV	1%

Neuroendocrine Pancreatic Tumors

Stage	5 year Survival Rate
Stage I	61%
Stage II	52%
Stage III	41%
Stage IV	16%

Pancreatic Cancer is hard to find early. The pancreas is located deep inside the body, so early tumors can’t be seen or felt during routine physical exams. People usually have no symptoms until the cancer has already spread to other organs. Screening tests are used to look for a disease in people with no evident symptoms.

Tests for Pancreatic Cancer

If a person has spotted any of the signs and symptoms that might be caused by Pancreatic Cancer, certain exams and tests needs to be done at the earliest.

Medical history and physical exam

The signs of Pancreatic Cancer along with other health problems are examined. The examination mostly focuses on the belly. Pancreatic Cancers can sometimes cause the liver or gallbladder to swell. Skin and the whites of the eyes will also be checked for jaundice (yellowing).

Imaging tests

Imaging tests use x-rays, magnetic fields, sound waves, or radioactive substances to create pictures of the pancreas. Imaging tests might be done for a number of reasons both before and after a diagnosis of Pancreatic Cancer, including:

To look for suspicious areas that might be cancer
To learn if and how far cancer has spread
To help determine if treatment is working
To look for signs of cancer coming back after treatment.

Computed tomography (CT) scan

The CT scan makes detailed cross-sectional images of the body. CT scans are often used to diagnose Pancreatic Cancer because they can show the pancreas clearly. They can also help show if cancer has spread to organs near the pancreas, as well as to lymph nodes and distant organs. A CT scan can help determine if surgery might be a good treatment option.

Magnetic resonance imaging (MRI)

MRI is a procedure that 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).

Ultrasound

Ultrasound tests use sound waves to create images of the pancreas.

Abdominal ultrasound: A wand-shaped probe called ultrasound transducer is moved over the skin of the abdomen. It gives off sound waves and detects the echoes as they bounce off organs. The transducer receives the echoes and sends them to a computer, which uses the echoes to make pictures called sonograms.
Endoscopic ultrasound (EUS): In this procedure, 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 off internal tissues or organs and make echoes to produce the sonogram. This procedure is also called endosonography.

Endoscopic retrograde cholangiopancreatography (ERCP): An endoscope is passed down the throat, through the esophagus and stomach, and into the first part of the small intestine.

A small amount of dye is then injected into the common bile duct, and x-rays are taken. This dye outlines the bile and pancreatic ducts. The x-rays can show narrowing or blockage in these ducts that might be due to Pancreatic Cancer. Sometimes, a small brush is put through the tube to remove cells for a biopsy.

Percutaneous transhepatic cholangiography (PTC): In this procedure, a thin, hollow needle is put through the skin of the belly and into a bile duct within the liver. A contrast dye is then injected through the needle, and x-rays are taken as it passes through the bile and pancreatic ducts. As with ERCP, this approach can also be used to take fluid or tissue samples. Because it is more invasive, PTC is not usually used unless ERCP has already been tried or can’t be done for some reason.

Somatostatin receptor scintigraphy (SRS)/OctreoScan

It can be very helpful in finding pancreatic neuroendocrine tumors (NETs). A hormone-like substance called octreotide that is bound to a radioactive substance is injected into a vein. Octreotide travels through the blood and attaches to the tumor cells of many types of NETs. A special camera is then used to trace the radioactivity in the body.

Positron emission tomography (PET) scan

For a PET scan, a slightly radioactive form of sugar is injected. A special camera is then used to create a picture of areas of radioactivity in the body.

This test is sometimes used to look for spread from exocrine Pancreatic Cancers, but because NETs grow slowly, they do not show up well on PET scans.

Angiography

This is an x-ray test that looks at blood vessels. A small amount of contrast dye is injected into an artery to outline the blood vessels, and then x-rays are taken.

An angiogram can show if blood flow in a particular area is blocked or compressed by a tumor. It can also show abnormal blood vessels in the area. This test can be useful in finding out if a Pancreatic Cancer has grown through the walls of certain blood vessels. Mainly, it helps surgeons decide if the cancer can be removed completely without damaging vital blood vessels, and it can also help them plan the operation.

Blood tests for

A procedure in which a blood sample is checked to measure the amounts of certain substances, such as bilirubin, 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.

Liver function tests: Jaundice (yellowing of the skin and eyes) is often one of the first signs of Pancreatic Cancer, but it can have many causes other than cancer.

Tumor markers: In this procedure a sample of blood, urine , or tissue is checked to measure the amounts of certain substances, such as CA 19-9, and carcinoembryonic antigen (CEA). Certain substances are linked to specific types of cancer when found in increased levels in the body. These are called tumor markers.

Biopsy

A small sample of tumor is removed and observed closely under the microscope. This procedure is called a biopsy. Biopsies can be done in different ways.

Percutaneous biopsy: A thin, hollow needle is inserted through the skin over the abdomen and into the pancreas to remove a small piece of a tumor. This is known as a fine needle aspiration (FNA).
Endoscopic biopsy: An endoscope is passed down the throat and into the small intestine near the pancreas. At this point, either endoscopic ultrasound (EUS) is used to pass a needle into the tumor or endoscopic retrograde cholangio pancreatography (ERCP) to remove cells from the bile or pancreatic ducts.
Surgical biopsy: Surgical biopsies are useful to find if cancer has spread beyond the pancreas and to other organs in the abdomen. The most common way to do a surgical biopsy is to use laparoscopy.

Once the cancer is diagnosed and its stage is determined then the treatment is planned based on the type of tumor and patients’ overall health condition. The treatment plan may indulge multiple phases involving more than one type of treatment.

Before rooting for a specific treatment plan, the doctor conducts multiple tests of the genes, tumor and other factors. Based on the results of these tests the most acute treatment strategy is formulated. Some of the advanced treatment options are discussed below:

Surgery
Surgery is the most preffered treatment when the tumor is restricted to the pancreas only and has not spread beyond it. Surgery includes removing all or part of the tumour depending on its location, size and extent of spread. It is highly efficient for treating cancers of early stages. However, the later stages of Pancreatic Cancer is difficult to treat and may involve more complex treatment plan
Neoadjuvant therapy
Neoadjuvant treatments are the preliminary treatment that aids in shrinking the tumor before proceeding for surgerical treatments. Some of the most commonly used neoadjuvant therapies are chemotherapy, radiation therapy and hormone therapy.
Adjuvant therapy
Adjuvant therapy refers to the after surgery treatments that helps to decrease the risk of recurring cancer incidences. Adjuvant therapy may begin within 8 weeks after surgery, based on the recovery rate and the overall health condition of the patient. Adjuvent therapy may include chemotherapy, radiation therapy, targeted therapy and palliative treatment.

Pancreatic Cancer is a very rare and aggressive type of Cancer. It grows very fast and does not show any sign and symptom at the earlier stages and hence finding a cure for the same becomes a bit difficult. There are several options for treatment but the outcome of the treatment may not be favourable.

If you encounter any of the symptoms then consulting a doctor is the smartest move though the symptom might not necessarily indicate the presence of the fatal disease. Also having any prior history or familial history of the disease calls for a regular examination alteast once a year. If one is suffering from diabetes or jaundice it is better to test for Pancreatic Cancer to be on the safer side.

Considering the location of the pancreas and the nature of Pancreatic Cancer it is very difficult to detect it at an early stage. However, being alert and going for regular examinations can definitely help one in diagnosing the disease.

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Pancreatic Cancer