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 cancerous cells have the ability to invade other parts of the body.[1] 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. These adenocarcinomas start within the part of the pancreas which makes digestive enzymes. Several other types of cancer, which collectively represent the majority of the non-adenocarcinomas, can also arise from these cells. 1-2% of cases of pancreatic cancer are neuroendocrine tumors, which arise from the hormone-producing cells of the pancreas. These are generally less aggressive than pancreatic adenocarcinoma.
Pancreatic cancer begins when abnormal cells within the pancreas grow out of control and form a tumor. There are two types of cells in the pancreas, the exocrine cells and endocrine cells. These cells also have different functions.
More than 95% of pancreatic cancers are classified as exocrine tumors. These tumors start in the exocrine cells that make pancreatic enzymes that help in digestion. Within this category, the vast majority of tumors are adenocarcinomas. The following table describes the different types of pancreatic exocrine tumors. Click here to learn about types of exocrine tumors in the pancreas.
Pancreatic neuroendocrine tumors (pancreatic NETs or PNETs) account for less than 5% of all pancreatic tumors. They may be benign or malignant and they tend to grow slower than exocrine tumors. They develop from the abnormal growth of endocrine (hormone-producing) cells in the pancreas called islet cells. This is why these tumors are sometimes referred to as “islet cell tumors.”
Pancreatic neuroendocrine tumors are either functional (produce hormones) or nonfunctional (produce no hormones). The majority of PNETs are nonfunctional tumors. Click here to learn about types of endocrine tumors in the pancreas.
Pancreatic cancer can be described according to where in the pancreas it occurs and by the type of cell that the cancer started from.
Cancer can occur in any part of the pancreas, but up to 8 out of 10 (80%), start in the head of the pancreas.
There are several different types of pancreatic cancer. The most common type is ductal adenocarcinoma, which starts from cells in the lining of the pancreatic ducts.
More than 9 out of 10 pancreatic cancers (95%) are ductal adenocarcinomas.
Other, less common, types of pancreatic cancer include:
cystic tumours – these are fluid-filled sacs in the pancreas, some of which are cancerous
acinar cell carcinomas – these start from the cells that make pancreatic juice
neuroendocrine tumours – these begin in the endocrine cells where insulin and other hormones are made
lymphoma – this is a cancer of the lymphatic tissue in the pancreas.
The treatments for cancerous cystic tumours and acinar cell carcinomas are similar to those described in our treatment section. But the tests and treatments for neuroendocrine tumours and lymphoma of the pancreas may be very different.
We have more information available about lymphoma and neuroendocrine tumours.
.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 cancerous 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. These adenocarcinomas start within the part of the pancreas which makes digestive enzymes. Several other types of cancer, which collectively represent the majority of the non-adenocarcinomas, can also arise from these cells. 1-2% of cases of pancreatic cancer are neuroendocrine tumors, which arise from the hormone-producing cells of the pancreas. These are generally less aggressive than pancreatic adenocarcinoma.
Signs and symptoms of the most common form of pancreatic cancer may include yellow skin, abdominal or back pain, unexplained weight loss, light-colored stools, dark urine and loss of appetite.There are usually no symptoms in the disease's early stages, and symptoms that are specific enough to suggest 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.
Pancreatic cancer rarely occurs before the age of 40, and more than half of cases of pancreatic adenocarcinoma occur in those over 70. Risk factors for pancreatic cancer include tobacco smoking, obesity, diabetes, and certain rare genetic conditions.About 25% of cases are linked to smoking,[6] and 5–10% are linked to inherited genes.Pancreatic cancer is usually diagnosed by a combination of medical imaging techniques such as ultrasound or computed tomography, blood tests, and examination of tissue samples (biopsy). The disease is divided into stages, from early (stage I) to late (stage IV).Screening the general population has not been found to be effective.
The risk of developing pancreatic cancer is lower among non-smokers, and people who maintain a healthy weight and limit their consumption of red or processed meat. A smoker's chance of developing the disease decreases if they stop smoking, and almost returns to that of the rest of the population after 20 years. Pancreatic cancer can be treated with surgery, radiotherapy, chemotherapy, palliative care, or a combination of these. Treatment options are partly based on the cancer stage. Surgery is the only treatment that can cure pancreatic adenocarcinoma, and may also be done to improve quality of life without the potential for cure. Pain management and medications to improve digestion are sometimes needed. Early palliative care is recommended even for those receiving treatment that aims for a cure.
In 2012, pancreatic cancers of all types were the seventh most common cause of cancer deaths, resulting in 330,000 deaths globally.Pancreatic cancer is the fifth most common cause of death from cancer in the United Kingdom,and the fourth most common in the United States. The disease occurs most often in the developed world, where about 70% of the new cases in 2012 originated. Pancreatic adenocarcinoma typically has a very poor prognosis: after diagnosis, 25% of people survive one year and 5% live for five years.] For cancers diagnosed early, the five-year survival rate rises to about 20%. Neuroendocrine cancers have better outcomes; at five years from diagnosis, 65% of those diagnosed are living, though survival varies considerably depending on the type of tumor.
The many types of pancreatic cancer can be divided into two general groups. The vast majority of cases (about 99%) occur in the part of the pancreas which produces digestive enzymes, known as the exocrine component. There are several sub-types of exocrine pancreatic cancers, but their diagnosis and treatment have much in common. The small minority of cancers that arise in the hormone-producing (endocrine) tissue of the pancreas have different clinical characteristics. Both groups occur mainly (but not exclusively) in people over 40, and are slightly more common in men, but some rare sub-types mainly occur in women or children.
The exocrine group is dominated by pancreatic adenocarcinoma (variations of this name may add "invasive" and "ductal"), which is by far the most common type, representing about 85% of all pancreatic cancers.Nearly all these start in the ducts of the pancreas, and pancreatic ductal adenocarcinoma is often abbreviated as PDAC. This is despite the fact that the tissue from which it arises – the pancreatic ductal epithelium – represents less than 10% of the pancreas by cell volume.[20] This cancer originates in the ducts that carry secretions (such as enzymes and bicarbonate) away from the pancreas. About 60–70% of adenocarcinomas occur in the 'head' of the pancreas.
The next most common type, acinar cell carcinoma of the pancreas, arises in the clusters of cells that produce these enzymes, and represents 5% of exocrine pancreas cancers. Like the 'functioning' endocrine cancers described below, acinar cell carcinomas may cause over-production of certain molecules, in this case digestive enzymes, which may cause symptoms such as skin rashes and joint pain.
Cystadenocarcinomas account for 1% of pancreatic cancers, and they have a better prognosis than the other exocrine types.
Pancreatoblastoma is a rare form, mostly occurring in childhood, and with a relatively good prognosis. Other exocrine cancers include adenosquamous carcinomas, signet ring cell carcinomas, hepatoid carcinomas, colloid carcinomas, undifferentiated carcinomas, and undifferentiated carcinomas with osteoclast-like giant cells. Solid pseudopapillary tumor is a rare low-grade neoplasm that mainly affects younger women, and generally has a very good prognosis.
Pancreatic mucinous cystic neoplasms are a broad group of pancreas tumors that have varying malignant potential. They are being detected at a greatly increased rate as CT scans become more powerful and common, and discussion continues as how best to assess and treat them, given that many are benign.
The small minority of tumors that arise elsewhere in the pancreas are mainly pancreatic neuroendocrine tumors (PanNETs).[24] Neuroendocrine tumors (NETs) are a diverse group of benign or malignant tumors that arise from the body's neuroendocrine cells, which are responsible for integrating the nervous and endocrine systems. NETs can start in most organs of the body, including the pancreas, where the various malignant types are all considered to be rare. PanNETs are grouped into 'functioning' and 'non-functioning' types, depending on the degree to which they produce hormones. The functioning types secrete hormones such as insulin, gastrin, and glucagon into the bloodstream, often in large quantities, giving rise to serious symptoms such as low blood sugar, but also favoring relatively early detection. The most common functioning PanNETs are insulinomas and gastrinomas, named after the hormones they secrete. The non-functioning types do not secrete hormones in a sufficient quantity to give rise to overt clinical symptoms. For this reason, non-functioning PanNETs are often diagnosed only after the cancer has spread to other parts of the body.
As with other neuroendocrine tumors, the history of the terminology and classification of PanNETs is complex. PanNETs are sometimes called "islet cell cancers",even though it is now known that they do not actually arise from islet cells as previously thought.
Bearing in mind that the disease is rarely diagnosed before the age of 40, common symptoms of pancreatic adenocarcinoma occurring before diagnosis include:
Pain in the upper abdomen or back, often spreading from around the stomach to the back. The location of the pain can indicate the part of the pancreas where a tumor is located. The pain may be worse at night and may increase over time to become severe and unremitting.[21] It may be slightly relieved by bending forward. In the UK, about half of new cases of pancreatic cancer are diagnosed following a visit to a hospital emergency department for pain or jaundice. In up to two-thirds of people abdominal pain is the main symptom, for 46% of the total accompanied by jaundice, with 13% having jaundice without pain.[5]
Jaundice, a yellow tint to the whites of the eyes or skin, with or without pain, and possibly in combination with darkened urine. This results when a cancer in the head of the pancreas obstructs the common bile duct as it runs through the pancreas.[28]
Unexplained weight loss, either from loss of appetite, or loss of exocrine function resulting in poor digestion.[5]
The tumor may compress neighboring organs, disrupting digestive processes and making it difficult for the stomach to empty, which may cause nausea and a feeling of fullness. The undigested fat leads to foul-smelling, fatty feces that are difficult to flush away.[5] Constipation is common.[29]
At least 50% of people with pancreatic adenocarcinoma have diabetes at the time of diagnosis.[4] While long-standing diabetes is a known risk factor for pancreatic cancer (see Risk factors), the cancer can itself cause diabetes, in which case recent onset of diabetes could be considered an early sign of the disease.[30] People over 50 who develop diabetes have eight times the usual risk of developing pancreatic adenocarcinoma within three years, after which the relative risk declines.[5]
The spread of pancreatic cancer to other organs (metastasis) may also cause symptoms. Typically, pancreatic adenocarcinoma first spreads to nearby lymph nodes, and later to the liver or to the peritoneal cavity, large intestine or lungs.[6] It is uncommon for it to spread to the bones or brain.[31]
Cancers in the pancreas may also be secondary cancers that have spread from other parts of the body. This is uncommon, found in only about 2% of cases of pancreatic cancer. Kidney cancer is by far the most common cancer to spread to the pancreas, followed by colorectal cancer, and then cancers of the skin, breast, and lung. Surgery may be performed on the pancreas in such cases, whether in hope of a cure or to alleviate symptoms.[32]
Pancreatic cancer begins when abnormal cells within the pancreas grow out of control and form a tumor. There are two types of cells in the pancreas, the exocrine cells and endocrine cells. These cells also have different functions.
More than 95% of pancreatic cancers are classified as exocrine tumors. These tumors start in the exocrine cells that make pancreatic enzymes that help in digestion. Within this category, the vast majority of tumors are adenocarcinomas. The following table describes the different types of pancreatic exocrine tumors. Click here to learn about types of exocrine tumors in the pancreas.
Pancreatic neuroendocrine tumors (pancreatic NETs or PNETs) account for less than 5% of all pancreatic tumors. They may be benign or malignant and they tend to grow slower than exocrine tumors. They develop from the abnormal growth of endocrine (hormone-producing) cells in the pancreas called islet cells. This is why these tumors are sometimes referred to as “islet cell tumors.”
Pancreatic neuroendocrine tumors are either functional (produce hormones) or nonfunctional (produce no hormones). The majority of PNETs are nonfunctional tumors. Click here to learn about types of endocrine tumors in the pancreas.
Types of pancreatic cancer
Pancreatic cancer can be described according to where in the pancreas it occurs and by the type of cell that the cancer started from.
Cancer can occur in any part of the pancreas, but up to 8 out of 10 (80%), start in the head of the pancreas.
There are several different types of pancreatic cancer. The most common type is ductal adenocarcinoma, which starts from cells in the lining of the pancreatic ducts.
More than 9 out of 10 pancreatic cancers (95%) are ductal adenocarcinomas.
Other, less common, types of pancreatic cancer include:
cystic tumours – these are fluid-filled sacs in the pancreas, some of which are cancerous
acinar cell carcinomas – these start from the cells that make pancreatic juice
neuroendocrine tumours – these begin in the endocrine cells where insulin and other hormones are made
lymphoma – this is a cancer of the lymphatic tissue in the pancreas.
The treatments for cancerous cystic tumours and acinar cell carcinomas are similar to those described in our treatment section. But the tests and treatments for neuroendocrine tumours and lymphoma of the pancreas may be very different.
We have more information available about lymphoma and neuroendocrine tumours.
.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 cancerous 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. These adenocarcinomas start within the part of the pancreas which makes digestive enzymes. Several other types of cancer, which collectively represent the majority of the non-adenocarcinomas, can also arise from these cells. 1-2% of cases of pancreatic cancer are neuroendocrine tumors, which arise from the hormone-producing cells of the pancreas. These are generally less aggressive than pancreatic adenocarcinoma.
Signs and symptoms of the most common form of pancreatic cancer may include yellow skin, abdominal or back pain, unexplained weight loss, light-colored stools, dark urine and loss of appetite.There are usually no symptoms in the disease's early stages, and symptoms that are specific enough to suggest 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.
Pancreatic cancer rarely occurs before the age of 40, and more than half of cases of pancreatic adenocarcinoma occur in those over 70. Risk factors for pancreatic cancer include tobacco smoking, obesity, diabetes, and certain rare genetic conditions.About 25% of cases are linked to smoking,[6] and 5–10% are linked to inherited genes.Pancreatic cancer is usually diagnosed by a combination of medical imaging techniques such as ultrasound or computed tomography, blood tests, and examination of tissue samples (biopsy). The disease is divided into stages, from early (stage I) to late (stage IV).Screening the general population has not been found to be effective.
The risk of developing pancreatic cancer is lower among non-smokers, and people who maintain a healthy weight and limit their consumption of red or processed meat. A smoker's chance of developing the disease decreases if they stop smoking, and almost returns to that of the rest of the population after 20 years. Pancreatic cancer can be treated with surgery, radiotherapy, chemotherapy, palliative care, or a combination of these. Treatment options are partly based on the cancer stage. Surgery is the only treatment that can cure pancreatic adenocarcinoma, and may also be done to improve quality of life without the potential for cure. Pain management and medications to improve digestion are sometimes needed. Early palliative care is recommended even for those receiving treatment that aims for a cure.
In 2012, pancreatic cancers of all types were the seventh most common cause of cancer deaths, resulting in 330,000 deaths globally.Pancreatic cancer is the fifth most common cause of death from cancer in the United Kingdom,and the fourth most common in the United States. The disease occurs most often in the developed world, where about 70% of the new cases in 2012 originated. Pancreatic adenocarcinoma typically has a very poor prognosis: after diagnosis, 25% of people survive one year and 5% live for five years.] For cancers diagnosed early, the five-year survival rate rises to about 20%. Neuroendocrine cancers have better outcomes; at five years from diagnosis, 65% of those diagnosed are living, though survival varies considerably depending on the type of tumor.
Types
The many types of pancreatic cancer can be divided into two general groups. The vast majority of cases (about 99%) occur in the part of the pancreas which produces digestive enzymes, known as the exocrine component. There are several sub-types of exocrine pancreatic cancers, but their diagnosis and treatment have much in common. The small minority of cancers that arise in the hormone-producing (endocrine) tissue of the pancreas have different clinical characteristics. Both groups occur mainly (but not exclusively) in people over 40, and are slightly more common in men, but some rare sub-types mainly occur in women or children.
Exocrine cancers
The exocrine group is dominated by pancreatic adenocarcinoma (variations of this name may add "invasive" and "ductal"), which is by far the most common type, representing about 85% of all pancreatic cancers.Nearly all these start in the ducts of the pancreas, and pancreatic ductal adenocarcinoma is often abbreviated as PDAC. This is despite the fact that the tissue from which it arises – the pancreatic ductal epithelium – represents less than 10% of the pancreas by cell volume.[20] This cancer originates in the ducts that carry secretions (such as enzymes and bicarbonate) away from the pancreas. About 60–70% of adenocarcinomas occur in the 'head' of the pancreas.The next most common type, acinar cell carcinoma of the pancreas, arises in the clusters of cells that produce these enzymes, and represents 5% of exocrine pancreas cancers. Like the 'functioning' endocrine cancers described below, acinar cell carcinomas may cause over-production of certain molecules, in this case digestive enzymes, which may cause symptoms such as skin rashes and joint pain.
Cystadenocarcinomas account for 1% of pancreatic cancers, and they have a better prognosis than the other exocrine types.
Pancreatoblastoma is a rare form, mostly occurring in childhood, and with a relatively good prognosis. Other exocrine cancers include adenosquamous carcinomas, signet ring cell carcinomas, hepatoid carcinomas, colloid carcinomas, undifferentiated carcinomas, and undifferentiated carcinomas with osteoclast-like giant cells. Solid pseudopapillary tumor is a rare low-grade neoplasm that mainly affects younger women, and generally has a very good prognosis.
Pancreatic mucinous cystic neoplasms are a broad group of pancreas tumors that have varying malignant potential. They are being detected at a greatly increased rate as CT scans become more powerful and common, and discussion continues as how best to assess and treat them, given that many are benign.
Neuroendocrine
Main article: Pancreatic neuroendocrine tumorThe small minority of tumors that arise elsewhere in the pancreas are mainly pancreatic neuroendocrine tumors (PanNETs).[24] Neuroendocrine tumors (NETs) are a diverse group of benign or malignant tumors that arise from the body's neuroendocrine cells, which are responsible for integrating the nervous and endocrine systems. NETs can start in most organs of the body, including the pancreas, where the various malignant types are all considered to be rare. PanNETs are grouped into 'functioning' and 'non-functioning' types, depending on the degree to which they produce hormones. The functioning types secrete hormones such as insulin, gastrin, and glucagon into the bloodstream, often in large quantities, giving rise to serious symptoms such as low blood sugar, but also favoring relatively early detection. The most common functioning PanNETs are insulinomas and gastrinomas, named after the hormones they secrete. The non-functioning types do not secrete hormones in a sufficient quantity to give rise to overt clinical symptoms. For this reason, non-functioning PanNETs are often diagnosed only after the cancer has spread to other parts of the body.
As with other neuroendocrine tumors, the history of the terminology and classification of PanNETs is complex. PanNETs are sometimes called "islet cell cancers",even though it is now known that they do not actually arise from islet cells as previously thought.
Signs and symptoms
Since pancreatic cancer usually does not cause recognizable symptoms in its early stages, the disease is typically not diagnosed until it has spread beyond the pancreas itself.[7] This is one of the main reasons for the generally poor survival rates. Exceptions to this are the functioning PanNETs, where over-production of various active hormones can give rise to symptoms (which depend on the type of hormone).[27]
Pain in the upper abdomen or back, often spreading from around the stomach to the back. The location of the pain can indicate the part of the pancreas where a tumor is located. The pain may be worse at night and may increase over time to become severe and unremitting.[21] It may be slightly relieved by bending forward. In the UK, about half of new cases of pancreatic cancer are diagnosed following a visit to a hospital emergency department for pain or jaundice. In up to two-thirds of people abdominal pain is the main symptom, for 46% of the total accompanied by jaundice, with 13% having jaundice without pain.[5]
Jaundice, a yellow tint to the whites of the eyes or skin, with or without pain, and possibly in combination with darkened urine. This results when a cancer in the head of the pancreas obstructs the common bile duct as it runs through the pancreas.[28]
Unexplained weight loss, either from loss of appetite, or loss of exocrine function resulting in poor digestion.[5]
The tumor may compress neighboring organs, disrupting digestive processes and making it difficult for the stomach to empty, which may cause nausea and a feeling of fullness. The undigested fat leads to foul-smelling, fatty feces that are difficult to flush away.[5] Constipation is common.[29]
At least 50% of people with pancreatic adenocarcinoma have diabetes at the time of diagnosis.[4] While long-standing diabetes is a known risk factor for pancreatic cancer (see Risk factors), the cancer can itself cause diabetes, in which case recent onset of diabetes could be considered an early sign of the disease.[30] People over 50 who develop diabetes have eight times the usual risk of developing pancreatic adenocarcinoma within three years, after which the relative risk declines.[5]
Symptoms of spread (metastasis)
The spread of pancreatic cancer to other organs (metastasis) may also cause symptoms. Typically, pancreatic adenocarcinoma first spreads to nearby lymph nodes, and later to the liver or to the peritoneal cavity, large intestine or lungs.[6] It is uncommon for it to spread to the bones or brain.[31]
Cancers in the pancreas may also be secondary cancers that have spread from other parts of the body. This is uncommon, found in only about 2% of cases of pancreatic cancer. Kidney cancer is by far the most common cancer to spread to the pancreas, followed by colorectal cancer, and then cancers of the skin, breast, and lung. Surgery may be performed on the pancreas in such cases, whether in hope of a cure or to alleviate symptoms.[32]
Risk factors[edit]
Risk factors for pancreatic adenocarcinoma include:
Age, gender, and ethnicity; the risk of developing pancreatic cancer increases with age. Most cases occur after age 65, while cases before age 40 are uncommon. 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, though incidence in Africa is low.
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. The risk declines slowly after smoking cessation, taking some 20 years to return to almost that of non-smokers.
Obesity; a BMI greater than 35 increases relative risk by about half.
Family history; 5–10% of pancreatic cancer cases have an inherited component, where people have a family history of pancreatic cancer. The risk escalates greatly if more than one first-degree relative had the disease, and more modestly if they developed it before the age of 50. Most of the genes involved have not been identified. Hereditary pancreatitis gives a greatly increased lifetime risk of pancreatic cancer of 30–40% to the age of 70.Screening for early pancreatic cancer may be offered to individuals with hereditary pancreatitis on a research basis. Some people may choose to have their pancreas surgically removed to prevent cancer developing in the future.
Pancreatic cancer has been associated with the following other rare hereditary syndromes: Peutz–Jeghers syndrome due to mutations in the STK11 tumor suppressor gene (very rare, but a very strong risk factor); dysplastic nevus syndrome (or familial atypical multiple mole and melanoma syndrome, FAMMM-PC) due to mutations in the CDKN2A tumor suppressor gene; autosomal recessive ataxia-telangiectasia and autosomal dominantly inherited mutations in the BRCA2 gene and PALB2 gene; hereditary non-polyposis colon cancer (Lynch syndrome); and familial adenomatous polyposis. PanNETs have been associated with multiple endocrine neoplasia type 1 (MEN1) and von Hippel Lindau syndromes.
Chronic pancreatitis appears to almost triple risk, and as with diabetes, new-onset pancreatitis may be a symptom of a tumor.[6] The risk of pancreatic cancer in individuals with familial pancreatitis is particularly high.
Diabetes mellitus is a risk factor for pancreatic cancer and (as noted in the Signs and symptoms section) new-onset diabetes may also be an early sign of the disease. 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.
Specific types of food (as distinct from obesity) have not been clearly shown to increase the risk of pancreatic cancer. 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).
Alcohol[edit]
Drinking alcohol excessively is a major cause of chronic pancreatitis, which in turn predisposes to pancreatic cancer. However, considerable research has failed to firmly establish alcohol consumption as a direct risk factor for pancreatic cancer. Overall, the association is consistently weak and the majority of studies have found no association, with smoking a strong confounding factor. The evidence is stronger for a link with heavy drinking, of at least six drinks per day
Diagnosis
The symptoms of pancreatic adenocarcinoma do not usually appear in the disease's early stages, and are individually not distinctive to the disease.
The symptoms at diagnosis vary according to the location of the cancer in the pancreas, which anatomists divide (from left to right on most diagrams) into the thick head, the neck, and the tapering body, ending in the tail.
Regardless of a tumour's location, the most common symptom is unexplained weight loss, which may be considerable. A large minority (between 35% and 47%) of people diagnosed with the disease will have had nausea, vomiting or a feeling of weakness. Tumors in the head of the pancreas typically also cause jaundice, pain, loss of appetite, dark urine, and light-colored stools. Tumors in the body and tail typically also cause pain.
People sometimes have recent onset of atypical type 2 diabetes that is difficult to control, a history of recent but unexplained blood vessel inflammation caused by blood clots (thrombophlebitis) known as Trousseau sign, or a previous attack of pancreatitis.A doctor may suspect pancreatic cancer when the onset of diabetes in someone over 50 years old is accompanied by typical symptoms such as unexplained weight loss, persistent abdominal or back pain, indigestion, vomiting, or fatty feces.Jaundice accompanied by a painlessly swollen gallbladder (known as Courvoisier's sign) may also raise suspicion, and can help differentiate pancreatic cancer from gallstones.
pancreatic cancer stage 4
Medical imaging techniques, such as computed tomography (CT scan) and endoscopic ultrasound (EUS) are used both to confirm the diagnosis and to help decide whether the tumor can be surgically removed (its "resectability"). Magnetic resonance imaging and positron emission tomography may also be used,[4] and magnetic resonance cholangiopancreatography may be useful in some cases.Abdominal ultrasound is less sensitive and will miss small tumors, but can identify cancers that have spread to the liver and build-up of fluid in the peritoneal cavity (ascites)It may be used for a quick and cheap first examination before other techniques.
A biopsy by fine needle aspiration, often guided by endoscopic ultrasound, may be used where there is uncertainty over the diagnosis, but a histologic diagnosis is not usually required for removal of the tumor by surgery to go ahead..
Liver function tests can show a combination of results indicative of bile duct obstruction (raised conjugated bilirubin, γ-glutamyl transpeptidase and alkaline phosphatase levels). CA19-9 (carbohydrate antigen 19.9) is a tumor marker that is frequently elevated in pancreatic cancer. However, it lacks sensitivity and specificity, not least because 5% of people lack the Lewis (a) antigen and cannot produce CA19-9. It has a sensitivity of 80% and specificity of 73% in detecting pancreatic adenocarcinoma, and is used for following known cases rather than diagnosis.
The most common form of pancreatic cancer (adenocarcinoma) is typically characterized by moderately to poorly differentiated glandular structures on microscopic examination. There is typically considerable desmoplasia or formation of a dense fibrous stroma or structural tissue consisting of a range of cell types (including myofibroblasts, macrophages, lymphocytes and mast cells) and deposited material (such as type I collagen and hyaluronic acid). This creates a tumor microenvironment that is short of blood vessels (hypovascular) and so of oxygen (tumor hypoxia).It is thought that this prevents many chemotherapy drugs from reaching the tumor, as one factor making the cancer especially hard to treat.
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