Pancreas cancer

Pancreatic cancer is found, according to various sources, in 1-7% of all cancers; more often in persons older than 50 years, predominantly in men.

Annually in the USA 30 500 cases of a cancer of a pancreas, first of all ductal adenocarcinoma, and 29 700 deaths are registered. Symptoms of pancreatic cancer include weight loss, abdominal pain and jaundice. The diagnosis is established by CT. Treatment of pancreatic cancer includes surgical resection and additional radiation and chemotherapy. The prognosis is unfavorable, since the disease is often diagnosed in advanced stages.

[1], [2], [3], [4], [5]

Causes of the pancreatic cancer

Causes of pancreatic cancer

Most of the pancreatic cancer lesions are exocrine tumors that develop from ductal and acinar cells. Endocrine tumors of the pancreas are discussed below.

Exocrine adenocarcinomas of the pancreas from the duct cells are found 9 times more often than from acinar cells; 80% of the head of the gland is affected. Adenocarcinomas appear on average at the age of 55 years and are 1.5-2 times more common in men. The main risk factors include smoking, chronic history of pancreatitis and, possibly, a prolonged course of diabetes mellitus (primarily in women). A certain role is played by heredity. Alcohol and caffeine consumption are probably not risk factors.

[6], [7], [8], [9], [10]

Symptoms of the pancreatic cancer

Symptoms

Symptoms of pancreatic cancer appear late; when a diagnosis is made, 90% of patients have a locally advanced tumor with retroperitoneal processes involved, regional lymph node involvement, or metastases to the liver or lungs.

Most patients have severe pain in the upper abdomen, which usually radiates to the back. Pain can decrease when the torso is tilted forward or in the fetal position. Characteristic weight loss. Adenocarcinomas of the pancreas head cause mechanical jaundice (often the cause of pruritus) in 80-90% of patients. Cancer of the body and tail of the gland can cause compression of the splenic vein, leading to splenomegaly, varicose veins of the esophagus and stomach and gastrointestinal bleeding. Pancreatic cancer causes diabetes in 25-50% of patients, manifested by symptoms of glucose intolerance (eg, polyuria and polydipsia), malabsorption.

Forms

Cystoadenocarcinoma

Cystoadenocarcinoma is a rare adenomatous pancreatic cancer that occurs as a result of malignant degeneration of the mucosa of the cystadenoma and is manifested by large volume formation of the upper abdominal cavity. The diagnosis is established by CT or MRI of the abdominal cavity, in which the cystic mass containing the decay products is usually visualized; volumetric formation can look like necrotic adenocarcinoma or pancreatic pseudocyst. In contrast to ductal adenocarcinoma, cystoadenocarcinoma has a relatively good prognosis. Only 20% of patients have metastases during surgery; complete removal of the tumor in distal or proximal pancreatectomy or Whipple surgery results in 65% 5-year survival.

[11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21]

Intra-flow papillary-mucinous tumor

Intra-flow papillary-mucinous tumor (WVMR) is a rare type of cancer, leading to hypersecretion of mucus and duct obturation. Histological examination may indicate benign, borderline or malignant growth. Most cases (80%) are observed in women and the process is localized most often in the tail of the pancreas (66%).

Symptoms of pancreatic cancer include pain syndrome and recurrent attacks of pancreatitis. The diagnosis is established with CT in parallel with endoscopic ultrasound, MRCPG or ERCP. Differentiation of a benign and malignant process is possible only after surgical removal, which is the method of choice. In surgical treatment, survival for 5 years with benign or borderline growth is more than 95% and 50-75% - in malignant process.

Diagnostics of the pancreatic cancer

Diagnostics

The most informative methods for diagnosing pancreatic cancer are spiral CT of the abdominal cavity and MRI of the pancreas (MRI). If CT or MRI of the pancreas reveals an unresectable tumor or metastatic disease, percutaneous fine-needle biopsy of the affected area is performed for histological examination of the tumor tissue and verification of the diagnosis. If CT demonstrates the potential resectability of a tumor or non-tumor formation, MRI of the pancreas and endoscopic ultrasound are shown to diagnose the stage of the process and small nodes that are not detected in CT. Patients with mechanical jaundice can perform ERCP as the first diagnostic study.

Routine laboratory tests should be performed. An increase in the level of alkaline phosphatase and bilirubin indicates an obstruction of the bile duct or metastasis to the liver. The determination of the CA19-9 antigen associated with the pancreas can be used to control patients with diagnosed pancreatic carcinoma and for screening at a high risk of developing cancer. However, this test is not sufficiently sensitive or specific for its use in screening a large population. Elevated antigen levels should decrease after successful treatment; a subsequent increase indicates a progression of the tumor process. Amylase and lipase levels usually remain within normal limits.

[22], [23], [24], [25], [26], [27], [28]

Treatment of the pancreatic cancer

Treatment of pancreatic cancer

Approximately in 80-90% of patients, the tumor is inoperable because of the detection of metastases or sprouting in the main vessels during diagnosis. Depending on the location of the tumor, the operation of choice is, most often, Whipple's operation (pancreatoduodenectomy). Usually, additional 5-fluorouracil (5-FU) therapy and external radiation therapy are prescribed, which allows survival of approximately 40% of patients for 2 years and 25% for 5 years. This combined treatment of pancreatic cancer is also used in patients with limited but inoperable tumors and leads on average to survival for about 1 year. More modern drugs (eg, gemcitabine) may be more effective than 5-FU as a basic chemotherapy, but there is no drug alone or in combination being more effective. Patients with liver metastases or distant metastases can be offered chemotherapy as part of the research program, but the prospect of treatment with or without treatment remains unfavorable and some patients may choose inevitability.

If an inoperable tumor that causes a violation of the patency of the gastroduodenal or biliary tract is detected during the operation, or if a rapid development of these complications is expected, double gastric and biliary drainage is performed to eliminate obstruction. In patients with inoperable lesions and jaundice, endoscopic stenting of the biliary tract allows one to resolve or reduce jaundice. However, in patients with inoperable processes, whose life expectancy is expected to be more than 6-7 months, it is advisable to superimpose a bypass anastomosis due to complications associated with stenting.

Symptomatic treatment of pancreatic cancer

Ultimately, most patients face severe pain and death. In this regard, the symptomatic treatment of pancreatic cancer is just as important as the radical. Appropriate assistance to patients in fatal prognosis should be considered.

Patients with a moderate or severe pain syndrome should be prescribed orally opioids at doses appropriate for pain relief. Anxiety about the development of addiction should not be a barrier to effective pain control. For chronic pain, longer-acting drugs (eg, subcutaneous administration of fentanyl, oxycodone, oxymorphone) are more effective. Percutaneous or intraoperative visceral (celiac) block allows to effectively manage pain in the majority of patients. In cases of unbearable pain, opiates are administered subcutaneously or intravenously; epidural or intraluminal administration provide an additional effect.

If palliative surgery or endoscopic biliary stenting does not reduce itching as a consequence of mechanical jaundice, the patient should be prescribed cholestyramine (4 g orally 1 to 4 times per day). Phenobarbital 30-60 mg may be effective orally 3-4 times a day.

With exocrine pancreatic insufficiency, tablets of pancreatic pig enzymes (pancrelipase) can be prescribed. The patient must necessarily take 16 000-20 000 units of lipase before each meal. If the food intake is prolonged (eg in a restaurant), the tablets should be taken during meals. The optimal pH for enzymes inside the intestine is 8; in this regard, some clinicians prescribe proton pump inhibitors or H ₂ -blockers. It is necessary to monitor the development of diabetes and its treatment.

Forecast

What is the prognosis of pancreatic cancer?

Cancer of the pancreas has a different prognosis. It depends on the stage of the disease, but always unfavorable (5 years of survival less than 2%) because of the diagnosis in the advanced stage.