Adenocarcinoma of the pancreas

Pancreatic adenocarcinoma is the most common histological form of malignant neoplasms of this organ of the paracrine system of the body.

Adenocarcinoma accounts for up to eight out of ten clinical cases of diagnosed pancreatic cancer.

In this disease, tumors are formed from the cells of the mucous membrane of the pancreas or from the epithelium of its excretory ducts. According to medical statistics, most often, pancreatic adenocarcinoma occurs against the background of chronic pancreatitis in older men who have bad habits.

[ 1 ], [ 2 ]

Causes of pancreatic adenocarcinoma

Malignant neoplasms are a consequence of damage to the genome of healthy cells, which begin to mutate and reproduce aggressively. But why this happens is not exactly known. And since the causes of pancreatic adenocarcinoma are currently unknown to science, oncologists are left to list hypothetical risk factors for the occurrence of this fatal pathology, identified on the basis of statistical analysis of case histories.

Thus, the pathogenesis of pancreatic adenocarcinoma, as well as other types of cancer of this gland, is associated with genetic oncopredisposition, chronic pancreatitis, diabetes, liver cirrhosis, consequences of removal of part of the stomach due to its pathologies. Also, their negative role can be played by smoking and alcohol abuse, poor nutrition (spicy and fatty foods, excess preservatives), obesity, and, of course, a sedentary lifestyle, which worsens the entire metabolic process. Experts note the carcinogenic effect of naphthylamine, benzidine, benzopyrene, asbestos, acetylaminofluorene and other chemicals on the pancreas.

But whatever the cause of pancreatic adenocarcinoma, it is a soft, irregularly shaped nodule. Its diameter can reach 10 cm or more. The proliferation of tumor cells is characterized by high activity. In this case, the epithelial tissue of the gland's stroma is quickly replaced by fibrous tissue.

This pathological process can capture the entire pancreas and go beyond it, affecting neighboring organs. And mutant cells with lymph or blood spread far from the original tumor, causing metastases in the duodenum, gall bladder, stomach, spleen, lymph nodes and peritoneal tissues.

[ 3 ], [ 4 ], [ 5 ]

Symptoms of pancreatic adenocarcinoma

The specific symptoms of pancreatic adenocarcinoma are largely determined by its location and growth rate.

In almost half of the cases, the tumor occurs in the head of the gland, and then adenocarcinoma of the head of the pancreas is diagnosed. In the exocrine part of the organ, that is, in the part where pancreatic juice with digestive enzymes is produced, ductal adenocarcinoma of the pancreas develops. And two-thirds of such adenocarcinomas are also localized in the head of the gland.

Moderately differentiated adenocarcinoma of the pancreas is characterized by the presence of a fairly dense node with unclear boundaries, consisting of ductal and glandular structures and small cysts. Alpha, beta and delta cells of the pancreatic islet tissue (islets of Langerhans), where the biosynthesis of hormones occurs: insulin, glucagon, c-peptide, somatostatin, etc., can be involved in the process of pathological mitosis.

With small tumor sizes, symptoms of pancreatic adenocarcinoma may not be felt. And this is the main reason for late seeking medical help. Growing, tumor nodes begin to squeeze the ducts of the organ, which leads to deterioration of the outflow of bile and pancreatic juice, or even to complete blockage of the ducts.

Then the symptoms begin to manifest themselves in the form of:

• nausea, belching, diarrhea (with particles of undigested food);
• loss of appetite and significant weight loss;
• severe pain in the epigastric region, which radiates to the back;
• yellowing of the skin and sclera, itching of the skin (mechanical jaundice due to compression of the bile duct);
• enlargement of the gallbladder;
• enlargement of the spleen;
• the presence of blood in the urine and feces (due to rupture of the dilated veins of the esophagus and stomach).

Both at the onset of the disease and at later stages (when the tumor decomposes), body temperature may increase. Most patients experience anemia and an increase in the white blood cell count (leukocytosis).

Diagnosis of pancreatic adenocarcinoma

Oncologists do not hide the fact that in the early stages of the disease, diagnosing pancreatic adenocarcinoma is very problematic, since its symptoms are similar to pancreatitis.

The list of diagnostic methods used includes:

• general blood test;
• biochemical blood test (for residual protein, sugar, urea, bilirubin, alkaline phosphatase, amylase and transaminases, tumor markers, antigens CA19-9, DuPan, Spanl, CA125, TAG72);
• urine analysis;
• endoscopic retrograde cholangopancreatography;
• contrast radioduodenoscopy;
• ultrasound examination (ultrasound);
• computed tomography (CT) with contrast;
• biopsy and histological examination of a tissue sample.

[ 6 ]

Treatment of pancreatic adenocarcinoma

Malignant tumors of the pancreas respond little or not at all to chemotherapy with cytostatic drugs, so the treatment of pancreatic adenocarcinoma is carried out mainly by surgery.

A radical operation (pancreatoduodenal resection) performed for adenocarcinoma of the head of the pancreas involves complete excision of the head of the gland, the duodenum and gall bladder, as well as part of the common bile duct and even the stomach. In such an operation, the patency of the gastrointestinal tract is restored by forming anastomoses between the organs. The fatality rate of such surgical interventions is at least 15%, and the survival rate for five years is no more than 10%.

Pancreatectomy (complete removal of the pancreas) is used in rare cases because its absence leads to an extremely complex form of diabetes.

Most often, surgical treatment is palliative in nature, and operations are performed to eliminate duct obstruction and remove mechanical jaundice.

A combination of chemotherapy and radiation is used as palliative measures (to alleviate the condition of patients). In particular, chemotherapy with the antimetabolite drug Gemzar (Gemcitabine), which is administered by intravenous infusions (1000 mg/m2 once a week for seven weeks), leads to a halt in the growth of adenocarcinoma.

Also, treatment of pancreatic adenocarcinoma is carried out to relieve pain. Depending on their intensity, doctors recommend taking such drugs as Paracetamol, No-shpa, Spazgan or Ketanov (Ketorolac). Ketanov is administered intramuscularly or taken orally. Orally, one tablet (10 mg) is prescribed 2-3 times a day. But this drug has side effects that can manifest as drowsiness, headache, increased sweating, nausea, abdominal pain, diarrhea or constipation.

In addition, to compensate for the deficiency of pancreatic juice enzymes, digestive enzyme preparations are prescribed: Pancreatin, Penzital, Creon, Pancitrate, Pancreatin, Enzistal, etc.

Prevention of pancreatic adenocarcinoma

As such, prevention of pancreatic adenocarcinoma is considered unlikely because in the early stages (which are asymptomatic) no one seeks examination.

And once adenocarcinoma of the head of the pancreas or ductal adenocarcinoma of the pancreas is diagnosed, the disease is usually already incurable.

Of course, it is necessary to lead a healthy lifestyle, follow a diet for pancreatic cancer and treat chronic pancreatitis, liver cirrhosis and diabetes.

Prognosis of pancreatic adenocarcinoma

The prognosis for pancreatic adenocarcinoma is, to put it mildly, unfavorable. This type of pancreatic tumor produces multiple metastases throughout the body, and very quickly. According to oncologists, the maximum life expectancy (from the moment of the onset of obvious symptoms of the disease) does not exceed 1.5 years. And only two patients out of a hundred with a diagnosis of pancreatic adenocarcinoma live up to five years. At the same time, after radical surgery, up to 27% of patients continue to live for five years. And compared to non-operated patients, life expectancy after repeated surgery for recurrent pancreatic adenocarcinoma increases threefold.