Pancreatic Cancer

Pancreatic cancer:
Definition:
Pancreatic cancer begins in the tissues of your pancreas — an organ in your abdomen that lies horizontally behind the lower part of your stomach. Your pancreas secretes enzymes that aid digestion and hormones that help regulate the metabolism of sugars.Pancreatic cancer often has a poor prognosis, even when diagnosed early. Pancreatic cancer typically spreads rapidly and is seldom detected in its early stages, which is a major reason why it's a leading cause of cancer death. Signs and symptoms may not appear until pancreatic cancer is quite advanced and surgical removal isn't possible.
Presentation:
Pancreatic cancer is sometimes called a "silent killer" because early pancreatic cancer often does not cause symptoms, and the later symptoms are usually nonspecific and varied. Therefore, pancreatic cancer is often not diagnosed until it is advanced. Common symptoms include:
* Pain in the upper abdomen that typically radiates to the back (seen in carcinoma of the body or tail of the pancreas)
* Loss of appetite and/or nausea and vomiting
* Significant weight loss
* Painless jaundice (yellow tint to whites of eyes and/or yellowish skin in serious cases, possibly in combination with darkened urine) when a cancer of the head of the pancreas (about 60% of cases) obstructs the common bile duct as it runs through the pancreas. This may also cause pale-colored stool and steatorrhea. The jaundice may be associated with itching as the salt from excess bile can cause skin irritation.
* Trousseau sign, in which blood clots form spontaneously in the portal blood vessels, the deep veins of the extremities, or the superficial veins anywhere on the body, is sometimes associated with pancreatic cancer.
* Diabetes mellitus, or elevated blood sugar levels. Many patients with pancreatic cancer develop diabetes months to even years before they are diagnosed with pancreatic cancer, suggesting new onset diabetes in an elderly individual may be an early warning sign of pancreatic cancer.
* Clinical depression has been reported in association with pancreatic cancer, sometimes presenting before the cancer is diagnosed. However, the mechanism for this association is not known.
* Symptoms of pancreatic cancer metastasis. Typically, pancreatic cancer first metastasizes to regional lymph nodes, and later to the liver and, less commonly, to the lungs; it occasionally metastasizes to bone or brain.
Alcohol:
It is controversial whether alcohol consumption is a risk factor for pancreatic cancer. Overall, the association is consistently weak and the majority of studies have found no association.Although drinking alcohol excessively is a major cause of chronic pancreatitis, which in turn predisposes to pancreatic cancer, chronic pancreatitis associated with alcohol consumption is less frequently a precursor for pancreatic cancer than other types of chronic pancreatitis.
Diagnosis:
Most patients with pancreatic cancer experience pain, weight loss, or jaundice.Pain is present in 80% to 85% of patients with locally advanced or advanced metastatic disease. The pain is usually felt in the upper abdomen as a dull ache that radiates straight through to the back. It may be intermittent and made worse by eating. Weight loss can be profound; it can be associated with anorexia, early satiety, diarrhea, or steatorrhea. Jaundice is often accompanied by pruritus and dark urine. Painful jaundice is present in approximately one-half of patients with locally unresectable disease, while painless jaundice is present in approximately one-half of patients with a potentially resectable and curable lesion.
Pathology:
The definitive diagnosis is made by an endoscopic needle biopsy or surgical excision of the radiologically suspicious tissue. Endoscopic ultrasound is often used to visually guide the needle biopsy procedure.
Exocrine pancreas cancers:
The most common form of pancreatic cancer (ductal adenocarcinoma) is typically characterized by moderately to poorly differentiated glandular structures on microscopic examination. Pancreatic cancer has an immunohistochemical profile that is similar to hepatobiliary cancers (e.g. cholangiocarcinoma) and some stomach cancers; thus, it may not always be possible to be certain that a tumour found in the pancreas arose from it.Pancreatic carcinoma is thought to arise from progressive tissue changes. Nonmalignant precursor lesions gradually change to cancerous lesions. The second most common type of exocrine pancreas cancer is mucinous.  [discuss] The prognosis is slightly better.[discuss]Other exocrine cancers include adenosquamous carcinomas, signet ring cell carcinomas,hepatoid carcinomas, colloid carcinomas, undifferentiated carcinomas, and undifferentiated carcinomas with osteoclast-like giant cells.
Pancreatic cystic neoplasms:
Pancreatic cystic neoplasms are a broad group of pancreas tumors that have varying malignant potential.
Endocrine pancreatic cancers:
Pancreatic endocrine tumors (PETs) are also called pancreatic neuroendocrine tumors (PNETs) and islet cell tumors. The annual clinically recognized incidence is low, about five per one million person-years. However, autopsy studies incidentally identify PETs in up to 1.5% most of which would remain inert and asymptomatic.The majority of PNETs are usually categorized as benign but the definition of malignancy in pancreas endocrine tumors has been ambiguous.
Prevention:
According to the American Cancer Society, there are no established guidelines for preventing pancreatic cancer, although cigarette smoking has been reported as responsible for 20–30% of pancreatic cancers.The ACS recommends keeping a healthy weight, and increasing consumption of fruits, vegetables, and whole grains, while decreasing red meat intake, although there is no consistent evidence this will prevent or reduce pancreatic cancer specifically. In 2006, a large prospective cohort study of over 80,000 subjects failed to prove adefiniassociation.The evidence in support of this lies mostly in small case-control studies.
Screening:
People who may have a high risk of pancreatic cancer due to a family history can be followed, but there is no consensus on what constitutes optimal monitoring. Several small studies have shown promising preliminary results for new biomarkers, but further validation on a larger scale is needed. People with pancreatic cancer themselves, or family members, may wish to participate in the activities at a research facility, or identify a pancreas tumor registry.
Treatment:
Exocrine pancreas cancer Surgery.
Treatment of pancreatic cancer depends on the stage of the cancer.[59] The Whipple procedure is the most common surgical treatment for cancers involving the head of the pancreas. This procedure involves removing the pancreatic head and the curve of the duodenum together (pancreato-duodenectomy), making a bypass for food from stomach to jejunum (gastro-jejunostomy) and attaching a loop of jejunum to the cystic duct to drain bile (cholecysto-jejunostomy). It can be performed only if the patient is likely to survive major surgery and if the cancer is localized without invading local structures or metastasizing. It can, therefore, be performed in only the minority of cases.Cancers of the tail of the pancreas can be resected using a procedure known as a distal pancreatectomy. Recently, localized cancers of the pancreas have been resected using minimally invasive (laparoscopic) approaches.
Chemotherapy:
In patients not suitable for resection with curative intent, palliative chemotherapy may be used to improve quality of life and gain a modest survival benefit. Gemcitabine was approved by the United States Food and Drug Administration in 1998, after a clinical trial reported improvements in quality of life and a 5-week improvement in median survival duration in patients with advanced pancreatic cancer. This marked the first FDA approval of a chemotherapy drug primarily for a nonsurvival clinical trial endpoint. Gemcitabine is administered intravenously on a weekly basis.
Endocrine pancreatic tumors:
The majority of these tumors are histologically benign. Treatment of pancreatic endocrine tumors, including the less common malignant tumors, may include:
* Watchful waiting: incidentally identified small tumors, for example on a computed tomography (CT) scan performed for other purposes, may conceptually not always need intervention, but criteria for watchful waiting are unclear.
* Surgery: tumors within the pancreas only (localized tumors), or with limited metastases, may be removed. For localized tumors, the surgical procedure is much less extensive than the types of surgery used to treat pancreatic adenocarcinoma.
* Hormone therapy: if the tumor is not amenable to surgical removal and is causing symptoms by secreting functional hormones, a synthetic hormone analog medication, octreotide, may lessen the symptoms, and sometimes also slows tumor growth.
* Radiation therapy: occasionally used if there is pain due to anatomic extension, such as metastasis to bone.
* Radiolabeled hormone: some PNETs absorb a hormone called norepinephrine and these may respond to nuclear medicine medication, radiolabeled MIBG therapy (or, experamentally, other hormones), given intravenously.
* Radiofrequency ablation (RFA), cryoablation, hepatic artery embolization
* Chemotherapy: in a small proportion of PNETs with undifferentiated histological features, or which grow rapidly despite other interventions, may receive chemotherapy. A subtype of PNETs, pancreatic neuroendocrine cancers, has received recent attention in the FDA approval of two medications in 2011 for use in this disease.
Epidemiology:
* Category:Deaths from pancreatic cancer
* Category:Pancreatic cancer survivors
* Gastrointestinal cancer
* Pancreatic Cancer Action Network (organization in the US)
* Pancreatic Cancer Action (organization in the UK)