Pancreatic Cancer Staging and Survival Rates

Tests and procedures to stage pancreatic cancer are usually done at the same time as diagnosis. For the proper staging of Pancreatic Cancer we should first highlight on how the cancer may spread in the human body.

The three ways that cancer spreads in the body are:

• Through tissue. Cancer invades the surrounding normal tissue.
• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

Pancreatic Cancer Stages

The following stages are used for pancreatic cancer:

Stage 0 (Carcinoma in Situ)

In stage 0, abnormal cells are found in the lining of the pancreas. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

In stage I, cancer has formed and is found in the pancreas only. Stage I is divided into stage IA and stage IB, based on the size of the tumor.

• Stage IA: The tumor is 2 centimeters or smaller.
• Stage IB: The tumor is larger than 2 centimeters.

Stage II

In stage II, cancer may have spread to nearby tissue and organs, and may have spread to lymph nodes near the pancreas. Stage II is divided into stage IIA and stage IIB, based on where the cancer has spread.

• Stage IIA: Cancer has spread to nearby tissue and organs but has not spread to nearby lymph nodes.
• Stage IIB: Cancer has spread to nearby lymph nodes and may have spread to nearby tissue and organs.

Stage III

In stage III, cancer has spread to the major blood vessels near the pancreas and may have spread to nearby lymph nodes.

Stage IV

In stage IV, cancer may be of any size and has spread to distant organs, such as the liver, lung, and peritoneal cavity. It may have also spread to organs and tissues near the pancreas or to lymph nodes.

• Stage IVA: Cancer has spread to organs, such as the stomach, spleen, and colon, that are near the pancreas, but it has not spread to distant organs, such as the liver or lungs.
• Stage IVB: Cancer has spread to organs, such as the stomach, spleen, or colon, that are near the pancreas or to places far away from the pancreas, such as the liver or lungs.

Recurrent

The cancer has come back (recurred) after it has been treated. It may come back in the pancreas or in another part of the body.

TNM System

One way to describe the stages of pancreatic cancer is to use the TNM system. This system uses three different codes to describe the size and location of the tumor, whether it has spread to the lymph nodes around the tumor, and whether it can be found in other parts of the body. Because doctors usually classify tumors during surgery and many patients with pancreatic cancer do not have surgery, the TNM system is not used as much with pancreatic cancer as it is for other diseases.

In the TNM system, “T” plus a letter or number (0 to 4) is used to describe the size and location of the tumor. The tumor stages are:

TX - The primary, or original, tumor cannot be evaluated because of incomplete information.

TO - There is no evidence of the primary site.
Tis (carcinoma in situ) - The cancer is present only in the lining of the pancreatic ducts.  

T1 - The cancer has not spread beyond the pancreas and is smaller than 2 centimeters (about ¾ inch).
T2 - The cancer has not spread beyond the pancreas, but is larger than 2 centimeters (about ¾ inch).
T3 - The cancer has spread from the pancreas to surrounding tissues near the pancreas but not blood vessels.
T4 - The cancer has spread from the pancreas into nearby large blood vessels.

The "N" in the TNM system stands for node. Lymph nodes are tiny organs shaped like beans that can be found throughout the body. Lymph nodes help the body fight infections. Regional lymph nodes are near the cervix, while distant lymph nodes are in other parts of the body. Lymph node stages are:

NX - The regional lymph nodes cannot be evaluated because of incomplete information.
N0 - The cancer has not spread into the regional lymph nodes.
N1 - The cancer has spread into the regional lymph nodes.

The "M" in the TNM system is used for cancer that has spread, or metastasized, to other parts of the body. The stages for metastatic pancreatic cancer are:

MX - Distant metastasis cannot be evaluated because of incomplete information.

M0 - The cancer has not metastasized, or spread, to distant lymph nodes (those not near the pancreas) or distant organs.

M1 - The cancer has spread to other parts of the body beyond the pancreas, such as the liver, lungs, or brain.

Stages for Surgery Availability

Determining pancreatic cancer's stage is often tricky. Imaging tests like CT scans and MRIs provide some information, but knowing exactly how far pancreatic cancer has spread usually requires surgery.

Since surgery has risks, doctors first determine whether pancreatic cancer appears to be removable by surgery (resectable). Pancreatic cancer is then described as follows:

• Resectable: On imaging tests, pancreatic cancer hasn't spread (or at least not far), and a surgeon feels it might all be removable. About 10% of pancreatic cancers are considered resectable when diagnosed.
• Locally advanced (unresectable): Pancreatic cancer has grown into major blood vessels on imaging tests, so the tumor can't safely be removed by surgery.
• Metastatic: Pancreatic cancer has clearly spread to other organs, so surgery can't remove it.

If pancreatic cancer is resectable, surgery could extend life and offer a small chance of cure.

Pancreatic cancer survival by stage

Survival rates are often used by doctors as a standard way of discussing a person's prognosis (outlook). Some patients with cancer may want to know the survival statistics for people in similar situations, while others may not find the numbers helpful, or may even not want to know them. Whether or not you want to read about the survival statistics below for cancer of the pancreas is up to you.

The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Of course, many people live much longer than 5 years (and many are cured).

Five-year relative survival rates assume that some people will die of other causes and compare the observed survival with that expected for people without the cancer. This is a better way to see the impact of the cancer on survival.

In order to get 5-year survival rates, doctors have to look at people who were treated at least 5 years ago. Improvements in treatment since then may result in a more favorable outlook for people now being diagnosed with cancer of the pancreas.

Survival rates are often based on previous outcomes of large numbers of people who had the disease, but they cannot predict what will happen in any particular person's case. Many other factors may affect a person's outlook, such as the patient's overall health and how well the cancer responds to treatment. Your doctor can tell you how the numbers below may apply to you, as he or she is familiar with the aspects of your particular situation.

The numbers below come from the National Cancer Institute's SEER database and are based on people diagnosed with exocrine cancer of the pancreas between 1988 and 2001.

Exocrine pancreatic cancer (5-year relative survival by stage)

               

Stage IA: 37%

Stage IB: 21%

Stage IIA: 12%

Stage IIB: 6%

Stage III: 2%

Stage IV: 1%

Overall, about 20% of people with pancreatic cancer live at least 1 year after diagnosis, while less than 4% will be alive after 5 years.

The statistics for pancreatic neuroendocrine cancers are not broken down by AJCC stages like cancers of the exocrine pancreas. Instead the statistics are broken down into different stages: localized (only in the pancreas), regional (spread to nearby lymph nodes or tissues), and distant (spread to distant sites, such as the liver). These numbers also come from the National Cancer Institute's SEER database:

Pancreatic neuroendocrine tumors (5-year relative survival by stage)

Localized: 87%

Regional: 70%

Distant: 24%

Overall: 42%

Sources and Additional Information:

http://www.cancer.gov/cancertopics/pdq/treatment/pancreatic/Patient/page2

http://www.umgcc.org/gi_program/pan-stages.htm

http://www.webmd.com/cancer/pancreatic-cancer/pancreatic-cancer-treatments-stage

http://www.caring4cancer.com/go/pancreatic/basics/what-are-the-stages-of-pancreatic-cancer.htm

http://www.cancer.org/Cancer/PancreaticCancer/DetailedGuide/pancreatic-cancer-survival-rates

Classification of Pancreatic Tumors

Benign and Malignant Pancreatic Tumors

Before getting to the point of reviewing different types of pancreatic cancers, we would like to point out that not all the pancreatic tumors are in fact cancerous.

Benign Pancreatic Tumors

The term "benign" refers to any substance that isn’t harmful or life-threatening. When referring to tumors, benign describes tumors that are non-cancerous. Most cases of benign pancreatic tumors occur as cystic tumors, growths that develop within a cyst’s membrane.

However, while cystic tumors such as mucinous cystadenoma and serous cystadenoma are typically harmless, the cystic tumor known as mucinous ductal ectasia is marked by a linking of potentially malignant cells that can eventually lead to the development of pancreatic cancer.

Symptoms of benign pancreatic tumors are nearly identical to those of the malignant type:

• abdominal pain
• back pain
• digestive problems
• nausea.

As a result, doctors use the same diagnostic procedures to evaluate whether or not a growth is a benign pancreatic tumor.

Malignant Pancreatic Tumors

Cancerous pancreatic tumors are referred to as malignant. Unfortunately, once a person starts to feel the symptoms of malignant pancreatic tumors, the pancreatic cancer has generally advanced to later stages, in which it is highly likely that cancer has spread (metastasized) to other parts of the body.

Because malignant pancreatic tumors are usually diagnosed after the cancer has progressed into later stages, the prognosis for malignant pancreatic tumors is disheartening: Less than 20 percent of pancreatic cancer patients survive more than a year after their diagnosis.

As a result, living a healthy lifestyle, understanding your genetic predisposition and the disease symptoms, and getting regular physical exams are the best approaches to prevent the development of malignant pancreatic tumors.

Types of Pancreatic Cancer

There are many types of pancreatic cancer that can be developed in human body. Though they differ in their speed of growth and propensity to spread, all pancreatic cancers share some similarities. First, all start as abnormal growths or tumors. These growths appear when the DNA of cells is mutated by carcinogens like tobacco, pesticides, and pollutants. These mutated cells multiply rapidly. They form tumors, which then spread by direct growth and metastasis, which occurs when cells split from the tumor to colonize other areas of the body.

There are several ways of the pancreatic cancer classification. They can be grouped according to where in the pancreas the cancer is or according to the type of cell the cancer has originated from. In terms of the location, cancer may affect the head, body or tail of the pancreas. Between 70 and 80% of pancreatic cancers are in the head of the pancreas.

The pancreas has two main types of cells, exocrine and endocrine. Each type can form different malignancies or benign tumors.

Exocrine Pancreatic Cancer

The vast majority of cancers of the pancreas are exocrine in type. This means that they start in the cells of the exocrine pancreas, which produces the digestive pancreatic juices. These are released into channels, or ducts, within the pancreas, and pass through the main pancreatic duct into the duodenum. There are a number of different types of exocrine pancreatic cancers.

More than 9 out of 10 exocrine pancreatic cancers are adenocarcinomas. Nearly all of these are ductal adenocarcinomas. These cancers start in the cells lining the ducts of the pancreas, occuring on the surface layer of the pancreas either on the head, body, or tail of the gland. Many occur on the head, which improves the prognosis because the tumors are usually discovered early due to the growths' symptoms. But if the tumors grow on the body or tail, symptoms only appear when the cancer has reached late stages. Adenocarcinomas are the most deadly type of pancreatic cancer. They are resistant to many treatments and grow rapidly. People diagnosed with this type usually only live 5 to 12 months. And the mortality rate of cases is about 95 to 97 percent.

There are rarer types of exocrine pancreatic cancer. The treatment for these rare types is more or less the same as for ductal adenocarcinoma. So surgery is the main treatment, if that is possible. The other rarer types of exocrine pancreatic cancer are

• Cystic tumors. Cystic tumors cause a cyst or fluid filled sac in the pancreas. Most pancreatic cysts are benign, but some are cancerous. Cystic cancers can have a better outlook (prognosis) than other types of exocrine pancreatic cancer.
• Cancer of the acinar cells. The acinar cells are at the ends of the ducts that produce the pancreatic juices.
• Sarcomas of the pancreas. These are cancers of the connective tissue holding together the cells of the pancreas. They are very rare and most often occur in children.

Endocrine Pancreatic Cancer

Endocrine tumors are uncommon. They start in the endocrine pancreas, where insulin and other hormones are made and released directly into the bloodstream. They are also called neuroendocrine tumors or islet cell tumors. 

About a third of these tumors produce hormones, which can cause some strange symptoms. Most of these tumors are non cancerous (benign). They are named after the hormone they produce

• Gastrinomas produce a hormone called gastrin,which stimulates the stomach to secrete acid and enzymes, causing peptic ulcers. Gastrinomas is a cluster of tumors in or near the pancreas. About half of these tumors are cancerous. Sometimes a gastrinoma occurs as part of multiple endocrine neoplasia, a hereditary problem which is caused by the endocrine glands. Diarrhea is the first symptom for this tumor. Frequent ulcers and abdominal pain can also be the symptoms. These tumors are very small and difficult to locate. If oral medicines are not enough then surgically the stomach is removed.
• Insulinomas produce insulin. Insulinomas are very rare, and less than 10 percent cause cancer. One of the more malignant cancer types is the cystadenoma. But only around half of these growths become malignant. And when they are diagnosed as cancerous, they are more treatable than the other types.
• Somatostatinomas produce a hormone called somatostatin. They are very rare, with only forty three or so cases reported. The tumor's presence produces diabetes mellitus, imbalances in hormones made by the pancreas, gallstones, and anemia.
• VIPoma, or vasoactive intestinal peptide tumor, is a tumor that produces excessive amounts of the hormone it's named for. Vasoactive intestinal peptide helps control how water transport is handled and transported in the digestive tract. The main symptom is diarrhea.
• Glucagonomas produce a hormone called glucagon. This tumor type causes high levels of glucagon that produces hyperglycemia, which is high blood sugar. The resulting symptoms are rashes (necrolytic erythema migrans), venous thrombosis, mental disturbances, and anemia result. Mild glucose intolerance is found in 90 percent of people with glucagonomas.
• PPomas are named for the secretion of pancreatic polypeptide (PP) hormone. The hormone's role is not understood. Abdominal pain and diarrhea result.
• GNRHomas encourage the secretion of human growth hormone. This controls growth, and an over secretion causes acromegaly.
• ACTHoma create adrenocorticotropic hormone, and almost all are cancerous. The hormone stimulates the adrenal cortex to produce cortisol. Cortisol increases blood pressure and blood sugar, and suppresses the immune system.

Two thirds of pancreatic endocrine tumors are called non functioning tumors as they do not produce any hormones or symptoms. Most of these tumors are cancer (malignant). 

Endocrine pancreatic tumors are treated differently to exocrine tumors and generally have a much better outlook (prognosis) than adenocarcinoma of the pancreas. These tumors are not always cancerous, but most stand a good chance of becoming malignant. Of the types of pancreas neuroendocrine tumors, the chances for malignancy are fairly high: glucagonomas (50-80 percent are malignant), somatostatinomas (70%), VIPomas (40-70%), PPomas (>60%), GNRHomas (60%), gastrinomas (60-90%), ACTHomas (>95%), and insulinomas (<10%).

Lymphoma of the Pancreas

Lymphoma of the pancreas is a very rare disease. Lymphoma is a cancer of the lymphatic system of the body. As the lymphatic system runs throughout the body, it can crop up anywhere. Because it is a different type of cancer, it is treated differently to the other types of pancreatic cancer.

Sources and Additional Information:

http://www.tree.com/health/pancreatic-cancer-types.aspx

http://www.pancreatictumorsandcancer.com/typesofpancreaticcancer.php

http://cancerhelp.cancerresearchuk.org/type/pancreatic-cancer/about/types-of-pancreatic-cancer

http://www.mayoclinic.org/pancreatic-cancer/types.html

http://www.pancreatic-tumors.com/pancreatic-tumor.html