What is pancreatic cancer? Causes, Symptoms and prevention
Pancreatic cancer is a type of cancer that starts when abnormal tissue cells grow in your pancreas, divide cells abnormally and form a tumor. The pancreas is an organ located behind the lower part of your stomach and in front of the spine. The pancreas generates enzymes that help digestion and hormones that control blood sugar. Cells names exocrine pancreas cells produce digestive enzymes, cells named endocrine pancreas cells make hormones. Most cases, pancreatic cancers begin in the exocrine cells.
The body organs like pancreas are made of cells and cells divides to generate new cells naturally when our body needs. The cells die when they become old, and new cells take place instead of dead cells. But sometimes the process failed and started forming new cells that our body does not want them, or our old cells do not die. The additional cells may build a mass of tissue called a tumor. And the tumor form with the malignant cells in the pancreas called pancreatic cancer.
The cells grow without any control and usually spread to the other nearby organs and tissues rapidly. Still, it is called pancreatic cancer even it spread to other nearby areas of pancreas because it started from that point. Often pancreatic cancer spread to the abdominal wall, liver, lungs, bones and/or lymph nodes.
Pancreatic cancer rarely detected in its initial stage. But some screening steps for people with pancreatic cysts or a family history of pancreatic cancer might help identify a problem early. Diabetes is one of the pancreatic cancer sign, particularly when it happens with weight loss, jaundice, and upper abdominal pain that spreads to the back.
In 2018, around 55,440 Americans (29,200 men and 26,240 women) were estimated to be diagnosed with pancreatic cancer. That’s mean, every day up to 150 people diagnosed for this cancer. This disease causes nearly 3% of all cancer. The pancreatic cancer rates in Black people are 25% higher than white people.
Also estimated around 44000 death (23,020 men and 21,310 women) will be in this year from this disease. In the U.S., this is the 8th most commonly diagnosed cancer in Women and 11th for men. Also, the 4th leading cause of cancer death and accountable for 7% of all cancer death.
The survival rate of 5 years will show you the percent of people live at least 5 years once cancer detected. The 5 years survival rate of a pancreatic cancer patient is 8%. However, survival rates depend on many factors such as the stage of cancer when identified.
The survival rate of 5 years is 32% if cancer detected at the early stage and can possible surgical removal of the tumor. But at this stage only 10% of people diagnosed. The survival rate is 12% if cancer spread to other nearby organ or tissue. 52% of people diagnosed after cancer affected the distant part of the body and their survival rate is 3%.
Remember, the survival rate statistics for the people with pancreatic cancer are an estimate. The estimates are on the annual data based on the number of pancreatic cancer patients in the United States. Experts also measure survival statistics every 5 years. The results of better diagnosis or available treatment may not show in the estimates for less than 5 years. If you need more information on it should talk with the doctor.
Types of Pancreatic Cancer
Exocrine or neuroendocrine (endocrine) tumors, both are the pancreatic tumors. This depends on the type of cells start growing. It is essential to know the type of pancreatic cancers because each type of pancreatic cancer acts differently and need different treatment.
Biology of each type of tumor is different. The patient information about tumor biology can provide through Molecular profiling.
Pancreatic Exocrine Tumors
Most of the pancreatic cancers (about 94%) are exocrine tumors. It began in the exocrine cells of the pancreas that makes enzymes to help the digestion process.
Pancreatic Exocrine Tumors
Adenocarcinoma is the most common type of pancreatic cancer. Around 9 people out of 10 pancreatic cancer patients suffer in this type of cancer. Adenocarcinoma is an exocrine tumor. It start growing in the cells lining of the pancreatic duct that produces enzymes for digestion.
Adenocarcinoma pancreatic cancer can affect other organs. But it is pancreatic adenocarcinoma if cancer starts from the pancreas.
Other Types of Exocrine Tumors
- The very rare type of pancreatic cancer is Acinar cell carcinoma. Some tumors may be the reason for produce too much lipase (fats digestion enzyme) in the pancreas.
- IPMN (intraductal papillary-mucinous neoplasm) tumor that starts growing either from the main pancreatic duct or from side branches of the duct. This type of tumor may start (not cancer) when diagnosed. But there is a chance that the tumor may turn in cancer. The risk becomes high when the IPMN grows in the main pancreatic duct.
- One of the rare, cancerous tumor is Mucinous cystadenocarcinoma. It is a cyst that filled by thick fluid. It’s similar to IPMN but grows in one part of the pancreas, generally the tail. These type of tumor mostly found in women.
There are other types of rare exocrine cancer. To get more information on it, visit your nearby pancreatic cancer treatment centre.
Pancreatic Neuroendocrine (endocrine) Tumors (PNETs)
Neuroendocrine tumors (pancreatic NETs or PNETs) are 6% of pancreatic cancers, also known as islet cell tumors. Often this type of cancer grows slower than exocrine tumors.
The unusual growth of endocrine cells in the pancreas known as islet cell form the PNETs. These cells generate hormones that help control blood sugar levels.
There are two types of pancreatic neuroendocrine tumors. One is functional (generate hormones), and another one is nonfunctional (not produce hormones). But most PNETs are nonfunctional.
The symptoms of pancreatic endocrine tumors are different. This type of pancreatic cancers acts differently than the most common pancreatic exocrine tumors and respond to different treatments.
The classification of PNETs made based on the hormones they produce. The common types are,
- Gastrinoma (gastrin)
- Glucagonoma (glucagon)
- Insulinoma (insulin)
- Somatostatinoma (somatostatin)
- VIPoma (vasoactive intestinal peptide)
- Nonfunctional Islet Cell Tumor (no hormones)
Causes of Pancreatic Cancer and Risks
The causes of pancreatic cancers are still unknown in most cases. But some factors have been identified that may increase the chances of developing it. It does not mean that having any risk factors will definitely develop pancreatic cancer. This type of cancer is most common in older people aged 75 or over. Rarely found in people under 40.
However, here are the following risk factors may increase the chances of developing pancreatic cancers,
Age: The development of pancreatic cancer risk increases with age. The majority of people who develop pancreatic cancer are over 45. Even 90% are older than 55, and 70% are older than 65. However, pancreatic cancer can be diagnosed for adults of any age.
Gender: According to the statistics we gave at the beginning of this article, men diagnosed with pancreatic cancer is 4% higher than women.
Race/ethnicity: The pancreatic cancer risk is 25% higher in black people than Asian, white people or Hispanic. People of Ashkenazi Jewish heritage are also at risk of pancreatic cancer. Read the family history below.
Family history: Sometimes pancreatic cancer may found run in the family or can be associated with genetic conditions which may increase the risk of other types of cancer. This is known as family pancreatic cancer. If 2/3 of your first blood family members diagnosed with pancreatic cancer may increase this type of cancer risk for you and your family. In here, first blood relatives mean your parents, siblings and children. The American Society of Clinical Oncology (ASCO) encourages people diagnosed with pancreatic adenocarcinoma to inform their doctor about the family cancer history if there any. In fact, for hereditary pancreatic cancer, people diagnosed with pancreatic adenocarcinoma may consider genetic testing, even without a strong family history. You can learn more about the risk of familial pancreatic cancer from ASCO.
Rare inherited conditions: Family members with certain rare inherited conditions also significantly increase the risk not only pancreatic cancer but also other types of cancer. These include the following,
- Hereditary pancreatitis (HP)
- Peutz-Jeghers syndrome (PJS)
- Familial malignant melanoma and pancreatic cancer (FAMM-PC)
- Hereditary breast and ovarian cancer (HBOC) syndrome
- Lynch syndrome
Also, people with the following rare inherited conditions are at high risk
- Li-Fraumeni syndrome (LFS)
- Familial adenomatous polyposis (FAP)
Smoking: The risk of pancreatic cancer is 2 to 3 times higher for the people who smoke cigarettes, cigars or chewing tobacco than those who don’t. Recent cancer research in the UK on lifestyle study found that about 1 out of 3 pancreatic cancer most probably linked to smoking. Give up smoking and stop using tobacco-related product may reduce the risk.
Alcohol: The UK cancer research also found that long-term heavy drinking may be the reason for chronic pancreatitis in about 7 out of 10 cases. Pancreatic cancer is more common in people with chronic pancreatitis.
Some research suggests there has a possible relationship between heavy drinking and pancreatic cancer risk. The result of the research showed the risk is higher for them who drink alcohol more than 6 units a day comparing with the people who drink less than 6 unit.
Diet: There is no clear idea about the link between diet and pancreatic cancer. But some research suggests there might have a possible link between red meat or processed meat with pancreatic cancer.
The research result found that the people are at high risk who ate more red or processed meat compared to those who don’t.
Obesity: A risk factor for pancreatic cancer is taking foods high in fat regularly. Research result found there is a high risk for obese and overweight men and women to develop pancreatic cancer and to die from this cancer because pancreas produces more insulin for overweight people. But still, more research needs to do for sure.
Diabetes: Many studies found that the people who are suffering from diabetes for a long time are in pancreatic cancer risk. Also, diabetes detected suddenly later in adulthood can be an early sign of pancreatic cancer. However, keep in mind that not all people who are suffering from diabetes or who develop diabetes as adults develop pancreatic cancer.
Chronic pancreatitis: Long-term inflammation of the pancreas is known as chronic pancreatitis, a painful pancreatic disorder. It happens most often because of long-term alcohol drinking. Some research has shown there is a link between chronic pancreatitis and developing pancreatic cancer, but isn’t liable for most cases.
Also, pancreatitis may run in families (hereditary pancreatitis) which is a rare condition, causing inflammation of the pancreas. It accounts for about 1% of cases of pancreatitis. It causes for a faulty gene inherited from parents.
Compared to other people, the risk of pancreatic cancer is 50 times higher for the people with hereditary pancreatitis.
Chemicals: Chemical exposure may increase the risk of developing pancreatic cancer such as benzene, certain dyes, petrochemicals and pesticides.
Infection of Helicobacter pylori: A common bacterium which is also known as H. pylori causes stomach ulcers and inflammation. H. pylori infection increase the risk of stomach cancer and pancreatic cancer. But in this case, pancreatic cancer risk is not as high as stomach cancer. However, millions of people infected with H. pylori worldwide and don’t have any health problem in most of the people.
Hepatitis viruses Infection: Liver infects by the hepatitis viruses. Some research has shown that long-term hepatitis B infection is linked to and increases pancreatic cancer risk. However, more research is needed to know more about this link.
Liver Cirrhosis: Alcohol abuse causes liver cirrhosis in the United States in most cases. When the liver cells damaged and replaced with scar tissue develops cirrhosis. Other reasons are viral hepatitis (Described above), excessive iron in the liver because of the disease called hemochromatosis, and other rare types of chronic liver disease.
Tooth or gum disease: Some research suggests people suffering tooth and gum disease increase the risk of pancreatic cancer. It’s unclear why this may happen, and the bacteria may play a role here which is the cause of tooth or gum disease.
Symptoms and signs of Pancreatic Cancer
Often doctor calls pancreatic cancer a ‘silent disease” because there are not many noticeable symptoms in its early stage. Also, no test currently available that can find cancer reliably in the people who don’t have any symptoms. But having one or more symptoms that we are going to describe below in this article does not mean you have pancreatic cancer. The signs are often similar to other medical conditions such as ulcer or pancreatitis. However, if you have any of these symptoms, you should visit a doctor to check them, which will help find the cause and treated if needed.
The exocrine pancreatic cancers and pancreatic neuroendocrine tumors (NETs) symptoms are often different, so we describe the symptoms separately in this article.
Exocrine Pancreatic Cancer Signs and symptoms
Often pancreatic cancers do not have any early signs or symptoms. By the time when they cause symptoms, they often spread outside of the pancreas already. Here is the following signs or symptoms you may see in Exocrine Pancreatic Cancer case,
- Jaundice & related symptoms
Jaundice is one of the first symptoms for most people with pancreatic cancer (and nearly all people with ampullary cancer). Yellowing eye and skin, itching, darkening of the urine and clay-colored stools are the signs of Jaundice.
Raise of bilirubin level causes jaundice, bilirubin made in the liver which is a dark yellow-brown color substance. The liver usually excretes bilirubin as part of a liquid known as bile. Bile reach into the intestines through common bile duct, where it helps break down fats. Finally, it leaves the body with the stool. When the common bile duct becomes blocked, it Interrupts bile reach in the intestines which increase the level of bilirubin in the body.
The head of the pancreas is close to the common bile duct. Cancers that start in the pancreas head can press on the bile duct and causes jaundice while they are still fairly small. This can sometimes help to diagnose the tumors at an early stage. But cancers that start from the pancreas body or tail don’t press on the duct until they spread through the pancreas. At this point, cancer often spreads beyond the pancreas.
When cancer spread to the other organ can affect the liver, which can cause jaundice.
- Stomach or back pain
Abdomen or back pain is common in pancreatic cancer. The tumor can grow fairly large that start in the body or tail of the pancreas, which causes pain when they start to press other nearby organs. Often it causes back pain when cancer spread to the nerves surrounding the pancreas. However, abdomen or back pain is fairly common and most of the time caused by something other than pancreatic cancer.
- Unintended weight loss and poor appetite
The common problem in people with pancreatic cancer is unintended weight loss. It can be caused because of incomplete digestion due to cancer. Weight loss related to cancer affects the body uses calories and protein. It can make the body consume more calories than expected, break down muscles. People with this cancer often have little or no appetite.
- Nausea and vomiting
Little or no appetite, indigestion, nausea and vomiting are common in people with pancreatic cancer. All or some of those symptoms may happen if the cancer block or slows the regular digestive system.
- Blood Clots
Sometimes, the first clue that the people have pancreatic cancer is a blood clot in a large vein, most of the time in the leg. It is called a deep vein thrombosis or DVT. Symptoms can include pain, swelling, redness, and warmth in the affected leg. A piece of the clot can be break sometimes and go to the lungs, which may cause breathing problem or chest pain. The name of a blood clot in the lungs is pulmonary embolism or PE.
Still, it doesn’t mean that you have cancer if you have a blood clot. Other things caused the blood clot most of the time.
- Enlargement of Gallbladder or Liver
Bile can be built in the gallbladder and make it larger if cancer blocks the bile duct. During the physical exam, a doctor can feel this as a large lump under the right side of the ribcage. The imaging test also can detect it.
If cancer spread to the liver, it can enlarge the liver sometimes. A doctor might be able to feel this below the right ribcage at the time of examination or might be detected in imaging test.
Some study suggests that suddenly detected diabetes in the people over age 50 or over can be an early symptom of pancreatic cancer, particularly in those people who have a low body mass index, weight loss experience or don’t have any family diabetes history.
However, pancreatic cancer rarely caused diabetes because they destroy the cells that make insulin. The symptoms could be feeling thirsty and hungry, and often urinate. More often, cancer can make small changes in blood sugar levels, which do not cause diabetes symptoms, but it can be detected by doing blood tests.
Pancreatic neuroendocrine tumors (NETs) Signs and Symptoms
Often excess hormone release into the bloodstream when Pancreatic neuroendocrine tumors (NETs) occurs. The symptoms may be different because of different hormones produced by different types of tumors.
These tumors produce hormone named gastrin that instructs the stomach to produce more acid. Zollinger-Ellison syndrome is a known condition that causes because of excessive gastrin. For that reason, the stomach generates excessive acid. This leads to stomach ulcers, which can cause pain, nausea, and loss of appetite. Bleeding can starts in case of severe ulcers. Mild bleeding can lead to anemia, and the symptoms could be feeling tired and problem in breathing. The stool can be black and tarry in case of more severe bleeding. Severe bleeding is life-threatening and needs immediate medical assistance.
The stomach acid can damage the intestinal lining cells if it reaches the small intestine. Also, they break down the digestive enzymes before they get the opportunity to digest food. The result may cause diarrhea and weight loss.
These tumors produce the hormone called glucagon that raises glucose (Sugar) level in the blood. Glucagonoma caused symptoms are mostly mild and something else causes the symptoms most of the time.
It can leads to diabetes if excess glucagon produces and increase blood sugar. Symptoms may include feeling thirsty and hungry and having to urinate often.
Diarrhea, weight loss, and malnutrition problems may also have in the people with these tumors. Other symptoms like Irritation of the tongue and the corners of the mouth might cause because of nutrition problems.
Most of the people with glucagonomas come to their doctor with the symptom known as necrolytic migratory erythema, which is a kind of red rash with swelling and blisters. This rash often can travels from place to place on the skin.
These tumors produce excessive insulin that lowers the blood glucose level which leads to low blood sugar. The symptoms might be the weakness, confusion, rapid heartbeat and sweating. If blood sugar becomes very low can lead to a person dies or even going into a coma and having seizures.
These tumors produce somatostatin that helps to control other hormones. The symptoms can include stomach pain, weight loss, poor appetite, diarrhea, signs of diabetes (thirsty and hungry feeling) and jaundice (yellow eyes and skin).
Early somatostatinoma symptoms are mild, and these symptoms are caused by other things most of the time. For that reason, these types of tumors are diagnosed at an advanced stage. Often, they are not possible to detect until spread to the liver and cause problems like pain and jaundice.
These tumors produce vasoactive intestinal peptide (VIP) substance. Excessive VIP can cause problems like diarrhea. Initially, the problems may be mild but become worse over time. Most people diagnosed when they have severe and watery diarrhea.
Apart from diarrhea, other symptoms are may be vomiting, nausea, muscle cramps, feeling tired and weak, and flushing (redness and warmth in the neck and face).
Also, people with these tumors tend to have low levels of acid in their stomachs, which can cause food digestive problems.
Over a long time, these tumors generated hormone-like substances can damage heart valves, causing weakness, breathing problem and an abnormal heart sound.
These tumors make a substance called pancreatic polypeptide (PP). This substance helps to control the exocrine and endocrine pancreas both. They can enlarge the liver and cause problems like belly pain. It can also cause watery diarrhea for some people.
- Carcinoid tumors
These tumors often produce serotonin, or it’s precursor 5-HTP. They first reach in the liver when the pancreatic tumor generates these substances. The liver breaks the substance before reaching the rest of the body and causing problems. For that reason, carcinoid tumors often don’t show any symptoms until they affect the outside of the pancreas.
At the point when these tumors do spread, it is most often to the liver. There, the cancer cells can directly release hormones into the blood leaving the liver. This can cause the carcinoid syndrome including symptoms like diarrhea, a rapid heart rate, wheezing and flushing (redness and warmth in the neck or face). These problems often happen in episodes, between which the person may feel fine.
Over a long time, these tumors generated hormone-like substances can damage heart valves, causing weakness, breathing problem and an abnormal heart sound.