Definition: Defining the Meaning of Pancreatic Cancer
Pancreatic cancer arises when cells in the pancreas, a glandular organ behind the stomach, begin to multiply out of control and form a mass. These cancer cells have the ability to invade other parts of the body. There are a number of types of pancreatic cancer. The most common, pancreatic adenocarcinoma, accounts for about 85% of cases, and the term "pancreatic cancer" is sometimes used to refer only to that type.
The pancreas is a gland that is about six inches in length and is located in the abdomen. The pancreas is surrounded by the stomach, liver, spleen and small intestine, and is shaped somewhat like a small pear. The wide end of the pancreas is referred to as the, 'head,' while the middle portion of it is called the, 'body.' The thin, end section of the pancreas is referred to simply as the, 'tail.' Bending backwards and underneath the head of the pancreas is an uncinate process of the gland.
The pancreas has two essential functions; the first is called the exocrine function, which involves production of enzymes that assist in digestion. The pancreas' second function is an endocrine one involving production of two hormones; insulin and glucon. Cells inside the pancreas create and secrete both glucon and insulin into the bloodstream; these hormones work in conjunction with each other to preserve proper levels of sugar in the blood.
If the cells within the pancreas begin to grow out of control, a tumor may develop. In the majority of cases of pancreatic cancer the cells which line the pancreatic duct are the ones that are involved. In these cases, the form of tumor is an exocrine tumor known as an, 'Adenocarcinoma.' There is another, less common form of pancreatic tumor that starts in islet cells in the pancreas; it is known as an, 'endocrine tumor.'
Forms of Exocrine Pancreatic Cancer
Ninety-five percent of all pancreatic cancers are Exocrine tumors; there are many types of Exocrine tumors. The most common type of Exocrine tumor is an Adenocarcinoma.
Acinar Cell Carcinoma
An Acinar Cell Carcinoma is a rare, cancerous tumor that might cause excessive production of pancreatic digestive enzymes.
An Adenocarcinoma is a form of tumor that accounts for nearly seventy-five percent of all forms of pancreatic cancers. It commonly starts in the cells that line the pancreatic duct. Adenocarcinomas might form glands or a collection of cells which surround an empty space.
An Adenosquamous Carcinoma is a form of tumor that is similar to an Adenocarcinoma because it creates glads, yet is different because it begins to flatten as it grows, and can imitate other types of cancers, showing squamous differentiation.
Giant Cell Tumor:
Giant Cell Tumors are very rare, and not as aggressive as Adenocarcinomas. They have unusually large cells. Still, they do not grow any larger than other forms of pancreatic tumors.
Intraductal Papillary-Mucinous Neoplasm (IPMN):
An Intraductal Papillary-Mucinous Neoplasm is a tumor that begins its growth in the pancreatic duct, or possibly from one of the side branches of the duct. The IPMN tumor seems to be somewhat finger-like, projecting into the duct, and can either be diagnosed as benign or malignant.
A Mucinous Cystadenocarcinoma is a rare, fluid-filled and cystic tumor that has the potential to develop into cancer over a period of time. It is a spongy tumor and the space inside is filled with a fluid called, 'mucin.' Among tumors, this form has a better prognosis that other forms of pancreatic tumors.
Pancreatoblastoma is another rare form of tumor, but is a malignant one. Pancreatoblastomas are usually found in children under the age of ten, which is why it is many times called the,'pancreatic cancer of infancy.' Fortunately, the prognosis for this form of cancer is better than some other forms of pancreatic cancer.
A Serous Cystadenocarcinoma is also rare. It is a benign, fluid-filled and cystic tumor that is sponge-like in appearance. Even though it can grow to be very large, it is almost always benign.
Solid and Pseudopapilslary Tumors:
Solid and Pseudopapilslary Tumors might begin anywhere in the pancreas. The parts of the tumor differ; some parts of solid, other parts have finger-like projections (papillary). Solid and Pseudopapsilslary tumors are found primarily in women in their thirties.
Metastatic Pancreatic Cancer
When a cancer spreads it is called, 'metastasizing.' As pancreatic cancer spreads outside of the pancreas itself, one of the places it spreads to is the lymph nodes which are nearby. These lymph nodes are a part of a more extensive lymph system that consists of ducts and vessels that exist throughout the entire body. These help the body to filter out foreign materials and remove them. With cancer cells in the lymph nodes it is very possible that cancer has spread to other tissues and organs in the body like the lungs or liver. Even though cancer may have spread to other organs in the body, it began in the pancreas, and is still referred to as Pancreatic Cancer and treated as such.
Types of Endocrine Pancreatic Cancer
Five-percent of pancreatic tumors are Endocrine tumors, also called, 'neuroendocrine tumors,' or, 'islet cell tumors.' In the pancreas are islet cells that produce hormones which are responsible for the production of glucon, insulin, and somatostatin. One of the major functions of these hormones is the control of the amount of sugar in the blood stream. Endocrine tumors are often slower to grow than other tumors, and can be either benign or malignant. Endocrine tumor may be either functional, in that they produce hormones; or they may be non-function, in that they do not. The tumors that are non-functional are malignant ninety-percent of the time. Below is a description of different types of Endocrine tumors.
Gastrinoma (Zollinger-Ellison Syndrome):
A Gastrinoma is commonly associated with abdominal pain, diarrhea, and recurrent ulcers; obtaining a diagnosis is often dependent upon finding elevated gastrin hormone levels, as well as imaging studies. Sometimes a Gastrinoma can be inherited, and when it is a part of a genetic syndrome called, 'Multiple Endocrine Neoplasia Type 1 (MEN1),' there is the potential for multiple tumors which may be located within the head of the pancreas, or within the duodenum. The majority of Gastrinomas are malignant; if they are not they have to potential to become malignant. With improved awareness and screening techniques, diagnosis of tumors while they are still benign is increasing.
A Glucogonoma is a form of tumor that is located in the tail and body of the pancreas, and is usually large. Many times it will metastasize. About seventy percent of all Glucagonomas are malignant; this form of pancreatic cancer can also be associated with diabetes, severe skin rashes, confusion and depression.
An Insulinoma is a common form of islet cell tumor; they are often small and hard to find. Fortunately, they are usually benign, but they tend to cause low blood sugar levels. Forms of tumors such as Multiple Endocrine Neoplasia Type 1 (MEN1), or, 'Wermer Syndrome,' many times present multiple tumors in the parathyroid glands and the pancreas. These tumors may be malignant as well. Symptoms from these tumors include muscle weakness and pain, fatigue, kidney stones, constipation, and bone thinning. People in their thirties and forties are usually the groups of people that experience these tumors.
Nonfunctional Islet Cell Tumor:
Nonfunctional Islet Cell Tumors are usually a malignant form of tumor, and do not cause well-defined symptoms like over-production of pancreatic hormones such as insulin.
Somatostatinomas are tumors that may arise in the Ampulla of Vater, but they can also occur anywhere in the pancreas itself. Their ability to become malignant varies, like most pancreatic endocrine tumors, and if they are not removed they have the potential to spread to other areas of the body.
Vasoactive Intestinal Peptide-Releasing Tumor:
Vasoactive Intestinal Peptide-Realizing Tumors, or, 'VIpoma,' or, 'Verner-Morrison Syndrome,' tumors are usually found in the tail and body of the pancreas. One of the symptoms of a Vasoactive Intestinal Peptide-Releasing tumor is severe diarrhea, as well as the loss of large amounts of potassium, a condition also known as, 'hypokalemia.' Around two-thirds of these tumors are found in women. This syndrome is known by another name; 'Watery Diarrhea,' but is called, 'Hypokalemia Achlorhydria,' (WDHA) Syndrome as well.
- Obesity; a BMI greater than 35 increases relative risk by about half.
- Most cases occur after age 65, while cases before age 40 are uncommon.
- The risk of pancreatic cancer in individuals with familial pancreatitis is particularly high.
- Diabetes mellitus is a risk factor for pancreatic cancer and new-onset diabetes may also be an early sign of the disease.
- Chronic pancreatitis appears to almost triple risk, and as with diabetes, new-onset pancreatitis may be a symptom of a tumor.
- The disease is slightly more common in men than women, and in the United States is over 1.5 times more common in African Americans.
- Family history; 5 to 10% of pancreatic cancer cases have an inherited component, where people have a family history of pancreatic cancer.
- People who have been diagnosed with Type 2 diabetes for longer than ten years may have a 50% increased risk, as compared with non-diabetics.
- Dietary factors for which there is some evidence of slightly increased risk include processed meat, red meat, and meat cooked at very high temperatures (e.g. by frying, broiling or barbecuing).
- Cigarette smoking is the best-established avoidable risk factor for pancreatic cancer, approximately doubling risk among long-term smokers, the risk increasing with the number of cigarettes smoked and the years of smoking.
Facts: Pancreatic Cancer Symptoms &
There are usually no symptoms in the disease's early stages, and symptoms that are specific enough to suspect pancreatic cancer typically do not develop until the disease has reached an advanced stage. By the time of diagnosis, pancreatic cancer has often spread to other parts of the body.
Signs and symptoms of the most common form of pancreatic cancer may include:
- dark urine
- yellow skin
- loss of appetite
- light-colored stools
- abdominal or back pain
- unexplained weight loss
Statistics: Pancreatic Cancer
The American Cancer Society's most recent estimates for pancreatic cancer in the United States are for 2015:
- About 40,560 people (20,710 men and 19,850 women) will die of pancreatic cancer
- About 48,960 people (24,840 men and 24,120 women) will be diagnosed with pancreatic cancer.
- Pancreatic cancer accounts for about 3% of all cancers in the US, and accounts for about 7% of cancer deaths.
- The average lifetime risk of developing pancreatic cancer is about 1 in 67 (1.5%). A person's risk may be altered by certain risk factors.
- The 5-year survival for localized pancreas cancer is 25.8%.
- Prevalence of this cancer: In 2011, there were an estimated 43,538 people living with pancreas cancer in the United States.
- Pancreatic cancer is the eighth most common cancer in women and the fourth leading cause of cancer death in men and women.
- Lifetime Risk of Developing Cancer: Approximately 1.5 percent of men and women will be diagnosed with pancreas cancer at some point during their lifetime, based on 2009-2011 data.
- Number of New Cases and Deaths per 100,000: The number of new cases of pancreas cancer was 12.3 per 100,000 men and women per year. The number of deaths was 10.9 per 100,000 men and women per year. These rates are age-adjusted and based on 2007-2011 cases and deaths.
- If the cancer is detected at an early stage when surgical removal of the tumor is possible, the five-year survival rate is about 26%. If the cancer has spread to the surrounding organs or tissue (regional spread), the five-year survival rate is 10%. If the cancer has spread to parts of the body far away from the ovary (distant spread), the five-year survival rate is 2%.