Pancreatic cancer refers to malignant tumors of the exocrine glands of the pancreas, which manifest as abdominal pain, loss of appetite, emaciation and jaundice, with a high degree of malignancy and poor prognosis. The age of onset is usually 45-65 years old.
The etiology and pathogenesis are unclear. High-risk factors and populations include.
1, long-term heavy smokers, alcohol drinkers, coffee drinkers.
2, long-term exposure to certain chemicals such as benzidine, F-naphthylamine, hydrocarbons, etc.
3.Patients with diabetes mellitus.
4, patients with chronic pancreatitis.
5, men, postmenopausal women.
Pathology.
Pancreatic cancer can occur in any part of the pancreas, with cancer of the head of the pancreas being common.
Most pancreatic cancers are ductal cell carcinomas, accounting for more than 90%, which are white, multi-fibrous, hard carcinomas prone to adhesions, and a few can be seen as follicular cell carcinomas, mucinous cystic carcinomas, islet cell carcinomas, etc.
The development of pancreatic cancer is fast, because of the richness of pancreatic blood vessels and lymphatic ducts and the lack of envelope of the alveoli, metastasis occurs at an early stage.
There are four types of metastasis: direct spread, lymphatic metastasis, hematogenous metastasis and metastasis along the nerve sheath.
Clinical manifestations.
It depends on the site of cancer, bile duct or pancreatic duct obstruction, the degree of pancreatic destruction and metastasis. The onset of the disease is insidious and there is no special symptom in the early stage; when obvious symptoms appear, the disease process is mostly in advanced stage.
Symptoms.
1, abdominal pain: often the first symptom; typical abdominal pain is: continuous, progressively increasing upper and middle abdominal pain or continuous severe pain in the lower back, may have paroxysmal colic, aggravated after meals, increased when lying on the back or spinal extension, can be relieved by lying prone, bending and kneeling position, the application of painkillers is poor.
2, weight loss: 90% of patients have significant weight loss, often cachexia in the late stage.
Jaundice: It is a prominent symptom of pancreatic head cancer, and jaundice appears in 90% of patients during the course of the disease. Most of the jaundice is caused by the compression or infiltration of common bile duct by pancreatic head cancer.
4.Other symptoms: such as indigestion, loss of appetite, nausea, vomiting, abdominal distension, etc.
Signs: wasting, epigastric pressure pain and jaundice can be seen. A cystic, non-pressure, smooth and pushable enlarged gallbladder can be detected, which is called Courvoisier’s sign and is an important sign for the diagnosis of pancreatic cancer. In some patients, a mass may be palpated in the upper abdomen. In advanced stage, ascites may appear; vascular murmur can be heard when pancreatic body tail cancer compresses splenic artery or aorta.
Ancillary examinations.
CT: It can show tumors >2 cm, and can show morphological changes of the pancreas, limited enlargement, loss of peripancreatic fat, dilatation or narrowing of the pancreatic duct, compression of large blood vessels, and lymph node metastasis.
Ultrasound: There is no obvious change in the early stage, while the advanced stage of pancreatic cancer may show limited enlargement of the pancreas and uneven echogenicity.
Ultrasound endoscopy: combined with laparoscopy in the omental cavity to directly observe the pancreas or indirect signs of the pancreas, and parallel biopsy, the detection rate can reach 100%.
ERCP and MRCP can show pancreaticobiliary duct compression and filling defects. ERCP can directly collect pancreatic fluid for cytological examination and pot belly biopsy, while MRCP has the advantage of non-invasive examination, and the disadvantage that minimally invasive treatment cannot be performed.
Barium radiography: In pancreatic head cancer, the duodenal flexure is enlarged or the medial side of the descending duodenum shows a reverse “3” sign.
Selective arteriography: Selective arteriography of superior mesenteric artery, hepatic artery and splenic artery via abdominal artery is effective in showing pancreatic tail cancer.
Histopathological and cytological examinations: high confirmation rate.
Blood, urine and stool examinations: corresponding laboratory changes may occur according to the progress of the patient’s disease. For example, elevated serum bilirubin may appear when pancreatic head cancer compresses the common bile duct, positive urinary bilirubin and negative urinary bilirubin when severe jaundice is present. Patients with pancreatic cancer will have elevated blood glucose and abnormal glucose tolerance.
Tumor markers: Tumor markers such as CEA and CA19-9 may be elevated in the serum of pancreatic cancer, but such changes are not absolute.
Diagnosis: Attention should be paid to those who are over 40 years old and have recently developed the following clinical manifestations.
1, persistent epigastric discomfort, aggravated after eating with loss of appetite.
2, unexplained progressive wasting.
3, unexplained diabetes mellitus or sudden exacerbation of diabetes mellitus.
4, multiple deep vein thrombosis or wandering phlebitis.
5, family history of pancreatic cancer, heavy smoking, chronic pancreatitis.
Differential diagnosis: chronic pancreatitis, carcinoma of the pot belly, carcinoma of the common bile duct, etc.
Treatment: The treatment of pancreatic cancer is still based on early surgical resection. For those who cannot be operated, palliative short-circuit surgery and radiotherapy are often done.