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胰腺癌 pancreatic cancer
Each year, about 37,000 people in the U.S. are diagnosed with pancreatic cancer. About one in 76
people in the U.S. will develop the disease. Pancreatic cancer affects about equal numbers of men
and women, almost always after the age of 45.
Cancer of the pancreas barely makes the top 10 most common cancers in the U.S. However,
pancreatic cancer's tendency to spread silently before diagnosis makes it the fourth deadliest
cancer diagnosis.
The American Cancer Society's most recent estimates for pancreatic cancer in the United States
are for 2012:


About 43,920 people (22,090 men and 21,830 women) will be diagnosed with pancreatic
cancer.
About 37,390 people (18,850 men and 18,540 women) will die of pancreatic cancer
Since 2004, rates of pancreatic cancer have increased about 1.5% per year.
The lifetime risk of developing pancreatic cancer is about 1 in 71 (1.41%). This is about the same
for men and women. A person's risk may be altered by certain risk factors (listed in the next
section).
胰腺有内分泌和外分泌两种功能，也就有内分泌和外分泌两种细胞。这两种细胞都会发生癌
变，来源自内分泌细胞的癌，叫神经内分泌癌，就是苹果公司总裁乔布斯得的那种癌，比较
少见，多数情况下恶性程度比较低，病程比较长，治疗方式与常见的胰腺癌也有所不同。来
自外分泌细胞的癌，就是我们常说的胰腺癌，是一种恶性程度比较高的肿瘤。多发生于中老
年人，发达国家发病率高于发展中国家。
Types of Pancreatic Cancer
外分泌细胞胰腺癌 Exocrine Pancreatic Cancer
Although there are several different types of pancreatic cancer, 95% of cases are due to 胰腺腺鱗
癌（pancreatic adenocarcinoma）.
Other less common exocrine pancreatic cancers include:鱗狀細胞癌（Squamous cell carcinoma）、
巨細胞癌（Giant cell carcinoma）、 腺泡細胞癌（Acinar cell carcinoma ）。
The exocrine pancreas makes up 95% of the pancreas, so it's not surprising that most pancreatic
cancers arise here.
内分泌細胞胰腺癌 Endocrine Pancreatic Cancer
Endocrine pancreatic cancers are quite rare, and are named according to what kind of
hormone-producing cell it starts from:胰島細胞癌 Insulinomas (from an insulin-producing cell) 、
高血糖素瘤 Glucagonomas (from a glucagon-producing cell)、 生長激素抑制素瘤
Somatostatinomas (from a somatostatin-making cell)、胃泌素瘤 Gastrinomas (from a
gastrin-producing cell)等。
Endocrine tumors usually are not cancer at all; they are nonmalignant growths. These "benign"
tumors are not considered pancreatic cancer. However, they may grow to a large size or secrete
unhealthy quantities of hormones, causing medical problems.
發病原因 Causes of Pancreatic Cancer
Pancreatic cancer occurs when cells in the pancreas grow, divide, and spread uncontrollably,
forming a malignant tumor. The exact cause of pancreatic cancer is unknown.
Smoking is the major risk factor for pancreatic cancer. Cigarette smoking roughly doubles the risk
for pancreatic cancer. People with diabetes or chronic pancreatitis are also at increased risk.
Age, male gender, and family history are other risk factors for pancreatic cancer.
預防 Prevention of Pancreatic Cancer
There is no known way to prevent pancreatic cancer. Not smoking, keeping a healthy weight, and
eating a plant-based diet should reduce your risk for pancreatic cancer.
診斷 Diagnosis of Pancreatic Cancer
In addition to a history and physical exam, imaging tests may be performed to help make the
diagnosis of pancreatic cancer. These tests include:
●Ultrasound
●Magnetic resonance imaging
●Endoscopic retrograde cholangiopancreatography (ERCP)
A definitive diagnosis of pancreatic cancer only comes from removal of cancer tissue (biopsy).
This can be done with a needle through the skin, during endoscopy, or with an operation.
Treatment for Pancreatic Cancer
Pancreatic cancer is treated in several ways, alone or in combination:●Surgery ●Chemotherapy
●Radiation therapy ●Palliative care
Surgery is generally done to attempt to cure pancreatic cancer, but it may also be done to lessen or
prevent symptoms. Chemotherapy and radiation are often given together, with or without surgery,
to slow pancreatic cancer's growth. Palliative care aims to reduce discomfort for people whose
pancreatic cancer cannot be cured.
What to Expect From Pancreatic Cancer
Pancreatic cancer is a serious condition. Most cases of pancreatic cancer have already spread at
the time of diagnosis, making a full cure unlikely. Treatments can allow people to live longer with
pancreatic cancer, and help them feel better. Clinical trials are ongoing to discover more effective
ways of treating pancreatic cancer.
Pancreatic Cancer Symptoms
Pancreatic cancer often goes undetected until it's advanced and difficult to treat. In the vast
majority of cases, symptoms only develop after pancreatic cancer has grown and begun to spread.
What are the symptoms of pancreatic cancer, and can any symptoms lead to earlier detection?
Because more than 95% of pancreatic cancer is the adenocarcinoma type, we'll describe those
symptoms first, followed by symptoms of rare forms of pancreatic cancer.
Pancreatic Cancer Symptoms:
局部症狀 Location Matters
Initially, pancreatic cancer tends to be silent and painless as it grows. By the time it's large enough
to cause symptoms, pancreatic cancer has generally grown outside the pancreas. At this point,
symptoms depend on the cancer's location within the pancreas:
●Pancreatic cancer in the head of the pancreas tends to cause symptoms such as weight loss,
jaundice (yellow skin), and fat in the stool, with or without abdominal pain.
●Pancreatic cancer in the body or tail of the pancreas usually causes belly pain and weight loss.
In general, symptoms appear earlier from pancreatic cancers in the head of the pancreas, compared
to those in the body and tail.
消化道症狀 Gastrointestinal Symptoms
Because pancreatic cancer grows around important areas of the digestive system, gastrointestinal
symptoms often predominate:
●Abdominal pain. More than 80% of people with pancreatic cancer eventually experience some
abdominal pain as the tumor grows. Pancreatic cancer can cause a dull ache in the upper belly and
back pain. The pain may come and go.
●Bloating. Some people with pancreatic cancer have a sense of early fullness with meals (satiety)
or an uncomfortable swelling in the abdomen.
●Nausea
●Diarrhea
●Fat in the stool (steatorrhea). As pancreatic cancer reduces the pancreas' ability to secrete
fat-digesting enzymes, more fat ends up in the stool. These fatty stools can be strange-smelling,
and float more than normal.
●Pale-colored stools. If the duct draining bile into the intestine is blocked by pancreatic cancer,
the stools may lose their brown color and become pale or clay-colored. Urine may become darker.
全身症狀 Constitutional (Whole-Body) Symptoms
As it grows and spreads, pancreatic cancer affects the whole body. Constitutional symptoms can
include:體重減輕 Weight loss、 萎靡不振 Malaise、食慾不振 Loss of appetite、 血糖升高
Elevated blood sugars. Some people with pancreatic cancer develop diabetes as the cancer impairs
the pancreas' ability to produce insulin. (However, the vast majority of people with a new
diagnosis of diabetes do not have pancreatic cancer.)
皮膚症狀 Skin Symptoms
黃疸 Jaundice: As pancreatic cancer blocks the duct that releases bile into the intestine (common
bile duct), the ingredients of bile build up in the blood. This turns the skin and the eyes yellow, a
condition called jaundice.
瘙癢 Itching: People with pancreatic cancer sometimes report itching all over. Blockage of the bile
ducts is often responsible.
Pancreatic Cancer Causes and Risk Factors
In 37,000 people per year in the U.S., pancreatic cancer arises, grows, and spreads, usually before
it's ever discovered. As with many types of cancer, the causes of pancreatic cancer are mysterious.
Although certain pancreatic cancer risk factors have been identified, the story is far from
complete.
Pancreatic Cancer Causes Still Unknown
Pancreatic cancer develops when a cell in the pancreas acquires damage to its DNA that causes it
to behave and multiply abnormally. A single cancer cell grows and divides rapidly, becoming a
tumor that does not respect normal boundaries in the body. Eventually, cells from the tumor can
travel elsewhere in the body (metastasize) through the blood or lymphatic system.
No one knows exactly how the process of DNA damage leading to pancreatic cancer happens.
Analyzing pancreatic cancers removed by surgery shows certain mutations that occur in nearly all
cases, and others that vary between people.
Some of these mutations happen randomly. Others occur in response to things we do or experience
in the environment. Some may be inherited. (What, when, and how each mutation occurs is
beyond experts' current understanding.) When enough mutations accumulate, a cell becomes
malignant and a tumor begins to grow.
Pancreatic Cancer Risk Factors
No one understands the underlying causes of pancreatic cancer, but certain risk factors for
pancreatic cancer have been identified. These factors are present more often in people who get
pancreatic cancer than in people who don't.
There are multiple pancreatic risk factors, although most are only weakly associated with
pancreatic cancer. Many people with pancreatic cancer don't have any one risk factor.
About one in 76 people will develop pancreatic cancer. This represents the average risk of
pancreatic cancer. People with any of the pancreatic risk factors are at slightly higher risk than the
general population:
●Genetics. Five percent to 10% of people with pancreatic cancer have an immediate family
member who also has pancreatic cancer. Several different genes have been associated with the
increased risk, although no "pancreatic cancer gene" has yet been identified.
●Diabetes. People with diabetes are slightly more likely to get pancreatic cancer. There's some
controversy in these cases as to whether diabetes causes pancreatic cancer, or if the pancreas starts
to malfunction before cancer develops, causing diabetes.
●Smoking. Cigarette smoking is well known to increase the risk for pancreatic cancer. The more a
person smokes, the higher the risk of pancreatic cancer. Ten years after quitting smoking, the risk
returns to about that of someone who never smoked.
●Obesity and inactivity. In a study of 88,000 nurses, those who were obese (body mass index
higher than 30) were more likely to develop pancreatic cancer. Those who exercised frequently
were about half as likely to get pancreatic cancer, compared to those who did not exercise at all.
●Diet. Can what we eat cause pancreatic cancer? A diet high in fat and meat (especially smoked
or processed meat) has been linked to pancreatic cancer in some studies. Eating a healthy diet rich
in fruits and vegetables decreased pancreatic cancer risk in other studies. Still other studies
suggest there's no identifiable link between diet and pancreatic cancer.
●番茄紅素和硒 Lycopene and selenium. Studies have shown low levels of these nutrients in some
people who developed pancreatic cancer. That's not proof that low levels cause pancreatic cancer,
though. Any diet that includes lean meat and red or yellow vegetables should provide adequate
lycopene and selenium.
Eliminating your risk factors for pancreatic cancer won't reduce your pancreatic cancer risk
entirely. But eating a healthy diet, keeping a healthy weight, and exercising frequently will
improve overall health, and reduce your risk of other health problems.
Pancreatic Cancer Diagnosis and Early Detection
Pancreatic cancer usually goes undetected until it's advanced. By the time symptoms occur,
diagnosing pancreatic cancer is usually relatively straightforward. Unfortunately, a cure is rarely
possible at that point.
The goal, of course, is detection and diagnosis at the earliest time possible. How is pancreatic
cancer diagnosed, and is early detection of pancreatic cancer possible?
(This section focuses on pancreatic adenocarcinoma, which account for more than 95% of
pancreatic cancer. Other rare forms of pancreatic cancer are mentioned at the end.)
Diagnosing pancreatic cancer usually happens when someone comes to the doctor after
experiencing weeks or months of symptoms. Pancreatic cancer symptoms frequently include
abdominal pain, weight loss, or jaundice (yellow skin). A doctor then embarks on a search for the
cause, using the tools of the trade:
●By taking a medical history, a doctor learns the story of the illness, such as the time of onset,
nature and location of pain, smoking history, and other medical problems.
●During a physical examination, a doctor might feel a mass in the belly, notice jaundiced skin, or
weight loss.
●Lab tests could show evidence that bile flow is being blocked, or other abnormalities.
Based on a person's examination, lab tests, and description of symptoms, a doctor often orders an
imaging test:
●Computed tomography (CT scan): A scanner takes multiple X-ray pictures, and a computer
reconstructs them into detailed images of the inside of the abdomen. A CT scan helps doctors
make a pancreatic cancer diagnosis.
●Magnetic resonance imaging (MRI): Using magnetic waves, a scanner creates detailed images of
the abdomen, in particular the area around the pancreas, liver, and gallbladder.
●Ultrasound: Harmless sound waves reflected off organs in the belly create images, potentially
helping doctors make a pancreatic cancer diagnosis.
●Positron emission tomography (PET scan): Radioactive glucose injected into the veins is
absorbed by cancer cells. PET scans may help determine the degree of pancreatic cancer spread.
If imaging studies detect a mass in the pancreas, a pancreatic cancer diagnosis is likely, but not
definite. Only a biopsy -- taking actual tissue from the mass -- can diagnose pancreatic cancer.
Biopsies can be performed in several ways:
●Percutaneous needle biopsy: Under imaging guidance, a radiologist inserts a needle into the mass,
capturing some tissue. This procedure is also called a fine needle aspiration (FNA).
●Endoscopic retrograde cholangiopancreatography (ERCP): A flexible tube with a camera and
other tools on its end (endoscope) is advanced from the mouth to the small intestine, near the
pancreas. ERCP can collect images from the area, as well as take a small biopsy with a brush.
●Endoscopic ultrasound: Similar to ERCP, an endoscope is advanced near the pancreas. An
ultrasound probe on the endoscope locates the mass, and a needle on the endoscope plucks some
tissue from the mass.
●Laparoscopy is a surgical procedure that uses several small incisions. Using laparoscopy, a
surgeon can collect tissue for biopsy, as well as see inside the abdomen to determine if pancreatic
cancer has spread. However, laparoscopy has higher risks than other biopsy approaches.
If pancreatic cancer seems very likely, and the tumor appears removable by surgery, doctors may
recommend surgery without a biopsy first, going for a cure.
Can pancreatic cancer be found early?
One reason for the often poor outlook for people with exocrine pancreatic cancer is that very few
of these cancers are found early. The pancreas is located deep inside the body, so early tumors
cannot be seen or felt by health care providers during routine physical exams. Patients usually
have no symptoms until the cancer has spread to other organs. Right now, there are no blood tests
to find early cancers of the pancreas. Doctors are looking to see if something called endoscopic
ultrasound can be useful in screening people with a high risk of pancreatic cancer.
Blood tests
A substance called CA 19-9 is released into the blood by exocrine pancreatic cancer cells and can
be detected by blood tests. But by the time blood levels are high enough to be consistently
detected by available methods, the cancer is no longer in its early stages. This is why the test is not
recommended for routine screening of people without symptoms or a known diagnosis of cancer.
The CA 19-9 test is sometimes used during treatment to see if the therapy is working or after
treatment to see if the cancer has recurred (come back).
Another substance, carcinoembryonic antigen (CEA), can help detect advanced pancreatic cancer
in some people. But it isn't sensitive enough to find the cancer early and is not recommended as a
screening test.
Genetic testing
Inherited DNA changes are thought to cause as many as 10% of pancreatic cancers. Because these
inherited cases are sometimes linked with other cancers, determining whether a patient's relatives
have an increased risk is not simple. Talking to someone with experience in hereditary cancer
syndromes（遺傳性癌症症候群） such as a genetic counselor, geneticist, or an oncologist (doctor
who specializes in caring for people who have cancer) is often helpful.
The American Cancer Society strongly recommends that any person considering genetic testing
talk with a genetic counselor, nurse, or doctor qualified to interpret and explain the test results
before they proceed with testing. It is important for people to understand and carefully weigh the
benefits and risks of genetic testing before these tests are done.
For people in families at high risk of pancreatic cancer, there are newer tests for detecting early
pancreatic cancer that may help. One of these is called endoscopic ultrasound. This test is not
used to screen the general public but might be used for someone with a strong family history of
pancreatic cancer. Using endoscopic ultrasound, doctors have been able to find early, treatable
pancreatic cancers in some members of high-risk families. In addition, interested families may
wish to participate in ongoing research studies aimed at investigating the genetic factors and
possible role of screening methods in those with a family history of the disease.
Pancreatic Cancer Treatments by Stage
The best treatment for pancreatic cancer depends on how far it has spread, or its stage. The stages
of pancreatic cancer are easy to understand. What's harder is determining the stage without
resorting to major surgery. In practice, doctors choose pancreatic cancer treatments based on
imaging studies and a person's individual factors.
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.
Questions to Ask Your Doctor About Pancreatic Cancer
A person who has been diagnosed with pancreatic adenocarcinoma should ask the doctor the
following questions:
●Where is my cancer located?
●How far has the cancer spread?
●What treatment options do I have?
●What is the overall goal of treatment in my case?
●If the expectation of therapy is not to cure the cancer, then when should I consider hospice or
palliative care and what do I need to know about advance directives?
●What are the risks and side effects of the proposed treatment?
●Am I eligible for a clinical trial? How do I find out?