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pancreatic cancer
Pancreatic cancer (also called cancer of the
pancreas) is a malignant tumour within the pancreatic gland. Each year
about 32,000 individuals in the United States are diagnosed with this
condition, and more than 60,000 in Europe. Depending on the extent of
the tumour at the time of diagnosis, the prognosis is generally
regarded as poor, with few victims still alive 5 years after
diagnosis, and complete remission still extremely rare.
About 95 percent of pancreatic tumors are adenocarcinomas (M8140/3).
The remaining 5 percent include other tumors of the exocrine pancreas
(e.g. serous cystadenomas), acinar cell cancers, and pancreatic
neuroendocrine tumors (such as insulinomas, M8150/1, M8150/3). These
tumors have a completely different diagnostic and therapeutic profile,
and generally a more favorable prognosis.
Signs and symptoms
Presentation
Early diagnosis of pancreatic cancer is difficult because
the symptoms are so non-specific and varied. Common symptoms include
abdominal pain, loss of appetite, significant weight loss and painless
jaundice. All of these symptoms can be blamed on other causes.
Therefore, diagnosis of pancreatic cancer is often late-stage in its
development.
Jaundice occurs when the tumour grows and pressure obstructs the
common bile duct, which runs partially through the head of the
pancreas. Tumours of the head of the pancreas (approximately 60% of
cases) will more easily give rise to such symptoms.
Depression has also been associated with pancreatic cancer, sometimes
presenting before the cancer is diagnosed. However, the mechanism for
this is not known.[1]
Predisposing factors
Risk factors for pancreatic cancer include [2]:
Age
Gingivitis or periodontal disease (Dana Farber Cancer Institute of
Harvard Medical School study: elevated levels of C-reactive protein, a
biomarker for chronic inflammation, and elevated oral bacteria and
carcinogenic nitrosamides- which interact with gastric acid-,are
found, especially in smokers, in pancreatic cancer cases)
Male gender
African ethnicity
Smoking
Diets high in meat
Obesity
Diabetes
Chronic pancreatitis has been linked, but is not known to be causal.
Occupational exposure to certain pesticides, dyes, and chemicals
related to gasoline
Family history
Helicobacter pylori infection
Diagnosis
Courvoisier's law defines the presence of jaundice and a
painlessly distended gallbladder as strongly indicative of pancreatic
cancer, and may be used to distinguish pancreatic cancer from
gallstones.
Pancreatic cancer is usually discovered during the course of the
evaluation of aforementioned symptoms. Liver function tests may show a
combination of results indicative of bile duct obstruction (raised
bilirubin, γ-glutamyl transpeptidase and alkaline phosphatase levels).
Ca 19.9 (carbohydrate antigen 19.9) is a tumor marker that is
frequently elevated in pancreatic cancer.
Imaging studies, such as ultrasound or abdominal CT may be used to
identify tumors. Endoscopic ultrasound (EUS) is another procedure that
can help visualize the tumor and obtain tissue to establish the
diagnosis.
Ohio State University Medical Center's medical oncology researchers
have found that in pancreatic cancer malignancies, the tumor contains
markedly higher levels of short molecule strands of certain micro-RNAs
(mi-RNA) than does the patient's benign pancreatic tissue or that
found in other healthy pancreases. This paves the way for two
possibilities: 1) a more early but likely expensive genetic and
biochemical molecular screening test profile- which would be an
innovation in this cancer; and 2) also possible new, creative and more
effective therapies based on the various micro-RNA levels. This opens
an exciting new front in confronting a very deadly cancer.
Treatment
Treatment of pancreatic cancer depends on the stage of the
cancer [3] Recent advances have made resection (surgical removal) of
tumors that were previously unresectable due to blood vessel
involvement possible. The Whipple procedure is the most common
surgical treatment for cancers involving the head of the pancreas.
Fluorouracil, gemcitabine, and erlotinib are the chemotherapeutic drug
agents of choice.
Stage Description App. % of cases Treatment options Median survival
Local/resectable Disease is confined to the pancreas and is clearly
separated from surrounding blood vessels 15 Surgery; postoperative
chemotherapy and/or radiation may also be offered 17 months
Locally advanced / unresectable Disease encases or compresses
surrounding blood vessels, or has directly extended into adjacent
structures 40 Chemotherapy (most commonly gemcitabine-based) and/or
radiation. In very rare instances, cancers that respond well to
initial treatment may subsequently be surgically resected. 8-9 months
Metastatic Evidence of extrapancreatic spread to distant organs
(liver, lungs, etc.) 45 Chemotherapy (most commonly gemcitabine-based);
investigational trials 4-6 months
On the back of the results of a Canadian led Phase III Randomised
Controlled trial involving 569 patients with advanced pancreatic
cancer, the US FDA has licensed the use of erlotinib (Tarceva) in
combination with gemcitabine as a palliative agent for this tumour.
This trial compared the action of gemcitabine/erlotinib vs gemcitabine/placebo
and demonstrated improved survival rates, improved tumour response and
improved progression free survival rates. New trials are now
investigating the effect of the above combination in the adjuvant and
neoadjuvant setting.[2]
In September 2006, it was announced that a new vaccine had been
developed to fight pancreatic cancer, with testing on human patients
showing promising results.(see [4][5])
Prognosis
Patients diagnosed with pancreatic cancer typically have a
poor prognosis partly because the cancer usually causes no symptoms
early on, leading to metastatic disease at time of diagnosis. Median
survival from diagnosis is around 3 to 6 months; 5-year survival is
much less than 5% [6]. With 32,180 new diagnoses in the United States
every year, and 31,800 deaths, mortality approaches 99%, giving
pancreatic cancer the #1 fatality rate of all cancers and the #4
cancer killer in the United States amongst both men and women. [7]
Pancreatic cancer occasionally may result in diabetes. Insulin
production is hampered and it has been suggested that the cancer can
also prompt the onset of diabetes and vice versa. [8]
Prevention
Prevention of pancreatic cancer consists of avoiding risk
factors when possible [9]. Cigarette smoking is considered to be the
most significant and avoidable risk factor for pancreatic cancer.
Maintaining a healthy weight and exercising may be helpful.
Additionally, increasing consumption of fruits, vegetables, and whole
grains while decreasing red meat intake is recommended.
In September 2006, a long term study concluded that taking Vitamin D
can substantially cut the risk of pancreatic cancer (as well as other
cancers) by up to 50%. (see [10] [11]</[12]). More studies of this
have been called for.
Awareness
November is Pancreatic Cancer Awareness Month
Purple is the traditional color chosen to represent pancreatic cancer
An estimated 52.7 million dollars was spent on pancreatic cancer
research in 2004 of the National Cancer Institute’s (NCI) cancer
research budget. This is just 1% of the NCI’s 4.824 billion dollar
cancer research budget for 2004. [13]
Despite the especially lethal nature of pancreatic cancer, the
research spending per pancreatic cancer patient is only $1145, the
lowest of any leading cancer. [14]
For a list of celebrities who have succumbed to this disease, see
Category:Pancreatic cancer deaths
The Pancreatic Cancer Action Network (PanCAN) was created as an
advocacy group for pancreatic cancer.
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