Pancreatic cancer is one of the more common malignancies and its incidence and mortality rate has increased significantly in recent years. The incidence of pancreatic cancer in the United States is 10/100,000, and up to 100/100,000 people over the age of 75 years die from pancreatic cancer every year about 20,000 people. In Japan, the mortality rate of pancreatic cancer in 1974 was 5 times higher than that in 1970, and there is a tendency to increase the mortality rate similar to lung cancer. According to the statistics of Shanghai, the incidence of pancreatic cancer was 1.16/100,000 in 1963, ranking 20th in the systemic malignant tumors, and 3.80/100,000 in 1977, jumping to 12th in malignant tumors; 6.92/100,000 in 1982, increasing to 6 times of 1963, jumping to 8th (male) and 12th (female) in malignant tumors. The incidence of this disease is higher in men than in women, and the ratio of men to women is 1.5~2:1, and male patients are much more common than premenopausal women The incidence of postmenopausal women is similar to that of men.
Clinical manifestations.
(a) Upper abdominal discomfort and vague pain are the most common first symptoms of pancreatic cancer
Although the tumor often causes obstruction of the pancreatic duct or bile duct, although it has not yet caused jaundice, the pressure in the bile duct is increased and the bile duct and gallbladder are dilated to varying degrees. The incidence of abdominal pain is even higher and can be due to the involvement of the abdominal plexus, resulting in significant upper abdominal pain and low back pain, the appearance of which often indicates that the lesion has reached an advanced stage.
(2) Loss of appetite and emaciation are also common manifestations of pancreatic cancer.
The tumor often obstructs the excretion of pancreatic juice and bile, thus affecting the patient’s appetite and causing significant weight loss due to digestive malabsorption.
(C) Obstructive jaundice is a prominent manifestation of pancreatic head cancer.
If the tumor site is close to the jugular area, jaundice can appear earlier. The jaundice is often persistent and progressively deepening, and the stool becomes pale or even vitrified with brown or bronze skin itching.
(D) In addition to obstructive jaundice, pancreatic head cancer often causes enlargement of the gallbladder, and obstructive jaundice with enlargement of the gallbladder can be clearly detected in the right upper abdomen, often suggesting the possibility of peri-potbelly tumors.
(E) Advanced pancreatic cancer may present with a fixed mass in the epigastrium with positive ascites sign and further may have manifestations of cachexia and liver, lung or bone metastases.
Diagnosis.
In addition to paying attention to the above clinical manifestations the following auxiliary diagnostic measures can be used.
(A) Laboratory tests
Serum bilirubin is significantly elevated, sometimes exceeding 342 μmol/L, with direct bilirubin as the main cause. Blood alkaline phosphatase value is also significantly elevated. Carcinoembryonic antigen (CEA) may be elevated in about 70% of pancreatic cancer patients, but it is not specific for CA19-9, a cancer-related antigen of the digestive tract, which is considered an indicator for the diagnosis of pancreatic cancer.
(B) Ultrasound
In addition to the main pancreatic duct, the branches of the pancreatic duct should be carefully observed. Some small pancreatic cancers can first cause limited dilatation of the branches of the pancreatic duct, such as dilatation of the pancreatic duct in the hooks. (ii) Ultrasound endoscopy can clearly depict the internal structures of the pancreas to detect early lesions.
(iii) CT scan
CT scan can show the correct location and size of the pancreatic mass and its relationship with the surrounding blood vessels, but about l/3 of pancreatic masses <2 cm cannot be detected as imaging changes. If the area is large, it may be a sign of tumor necrosis or liquefaction; (2) the cancer may dilate when it invades or compresses the bile duct or pancreatic duct; (3) the cancer may invade the dorsal fat layer of the pancreas and encircle the superior mesenteric vessels or inferior vena cava.
(iv) Magnetic resonance imaging (MRI)
MRI can show abnormal pancreatic contours and can determine early local invasion and metastasis based on the signal level of T1-weighted image. MRI is superior to CT scan in determining pancreatic cancer, especially small pancreatic cancer confined to the pancreas, and whether there is peripancreatic spread and vascular invasion.
(E) Endoscopic retrograde cholangiopancreatography (ERCP)
ERCP can simultaneously show the pancreatic ducts, bile ducts and jugular abdomen, and is valuable for unexplained obstructive jaundice, in addition to direct observation of the duodenal papilla and collection of pancreatic fluid for cytological examination. (1) irregular stenosis and obstruction of the main pancreatic duct with a rat tail-like truncated image at the end; (2) disruption of the side branches of the main pancreatic duct with sparse fracture and displacement; (3) spillage of contrast into the tumor area; (4) encapsulated stenosis and obstruction of the common bile duct, such as stenosis and obstruction of the pancreatic duct at the same time, then there is a “double duct sign”.
(VI) Gastrointestinal barium meal examination (GI)
In the advanced stage of pancreatic head cancer, there may be enlargement of the duodenal circle or the duodenum may be changed in a reverse “3” shape. The hypotonic GI examination will make the duodenal smooth muscle relaxation and peristalsis decrease, thus facilitating the observation of changes in the duodenal mucosa, such as texture disorder and mucosal wall stiffness.
(VII) Cytological examination
The main diagnostic function of cytological examination is to diagnose pancreatic cancer in advanced stage inoperable patients, and it can also be used intraoperatively instead of pancreatic biopsy to avoid complications such as acute pancreatitis due to bleeding pancreatic fistula caused by biopsy. The early diagnosis of pancreatic cancer has been a problem that has been explored and solved.
Treatment
Surgical resection The treatment of pancreatic cancer is mainly surgical, but a considerable number of patients are in the middle and late stages of the disease and cannot undergo radical resection. The surgical resection rate of pancreatic head cancer is about 15%, and the resection rate of pancreatic body tail cancer is even lower than 5%.
1.Pancreatic head duodenectomy (PD): it is the first choice of radical resection for pancreatic head cancer, which was pioneered by Whipple in 1935. Although many scholars have made many reforms in the next 50 years regarding the reconstruction of the digestive tract after resection, it is still customary to refer to pancreaticoduodenectomy as Whipple’s operation.
Indications: PD is suitable for pancreatic head carcinoma with good general condition, age <70 years, no liver metastasis, no ascites, and late infiltration of surrounding blood vessels.
2.Total pancreatectomy (TP): indications: cancer affecting the whole pancreas without liver metastasis and peritoneal implantation is the absolute indication for total pancreatectomy The advantages of total pancreatectomy are that in addition to the complete removal of multiple lesions in the pancreas, the removal of lymph nodes around the pancreas is more convenient and complete. Therefore, the indications for TP should be strictly controlled. Therefore, the decision to perform TP should not be based only on the local condition of the pancreatic lesion, but more importantly, the patient’s awareness of the disease should be taken into consideration. The patient and family members should understand whether they can inject insulin on their own or whether the family members can assist in the management of diabetes and their financial status. TP
3, pancreatic caudal resection (DP): it is suitable for those with pancreatic caudal cancer without metastasis, together with the spleen, pancreatic caudal tumor and surrounding lymph nodes, and the operation is simple, with few surgical complications and low mortality rate.
4.Pancreaticoduodenectomy with preservation of the pylorus (PPPD): PPPD is only applicable to small pancreatic head cancer, duodenal bulb and gastric pylorus without direct infiltration of cancer in the lymph nodes around the stomach without metastasis.
(C) diversion of unresectable pancreatic cancer
Because of the difficulty of early diagnosis of pancreatic cancer, the rate of radical resection is still very low, so that a considerable number of cases need to perform some kind of surgery or other to relieve symptoms. The choice of bile-intestinal diversion can be decided according to the location of the tumor. “If the tumor is close to the bile duct into the pancreas, it is best to perform an end-lateral anastomosis of the common bile duct with a Roux-Y collar of the jejunum whenever possible to prevent the cancer from invading up the common bile duct to the opening of the cystic duct and causing the diversion to fail. In addition, if it is considered that the tumor will not survive for more than 1 year, a simpler bile-intestinal drainage procedure can be used – the T-tube bridging jejunostomy is performed by placing the T-tube placed in the common hepatic duct through the transverse colonic mesentery into the jejunum 20 cm below the flexor ligament and fixing it properly. intestinal peristalsis recovery early peristaltic siphoning will accelerate bile excretion to facilitate digestion and absorption until the long-term retention of foreign bodies affects the patient has long died due to tumor progression as for gastrojejunostomy its indications are: ① clinical symptoms or signs of duodenal obstruction ② gastrointestinal fluoroscopy or endoscopy to see the duodenum has a stenosis rigid cancerous infiltration ③ intraoperative compression of duodenal stenosis
(iv) Radiation therapy
In recent years, with the development of intraoperative radiotherapy and multifield external radiotherapy under CT precise positioning for treatment planning, radiotherapy has become one of the main means of treatment for pancreatic cancer, and the radiation tolerance of the surrounding pancreatic area such as stomach, small intestine, liver, kidney and spinal cord is low.
Intraoperative radiotherapy uses 10-20MV high-energy electron beam to fully reveal the tumor and remove the tumor as far as possible to displace the surrounding normal tissues, and then accurately place the corresponding limiting light cylinder on the tumor. CT precise positioning for radiation treatment plan so that the pancreatic cancer lesion can be irradiated with high dose and the surrounding normal tissues can be better protected with 10mV x-ray in the front of the abdomen plus both sides of the field and other central irradiation 180-200cGy each time 5 times a week at a dose of 40-60Gy / 4-6 weeks can be continuous treatment or segmental treatment
(E) Chemotherapy
This is mainly due to two reasons: on the one hand, the biological characteristics of the tumor are not sensitive to chemotherapy and there is no ideal observation index in the study, so clinicians are often not interested in it. On the other hand, pancreatic cancer patients often show nausea, vomiting, anorexia, weight loss and malabsorption, so it is difficult to tolerate systematic chemotherapy.
Systematic chemotherapy for pancreatic cancer: many papers have reported clinical experiments on the effectiveness of combination chemotherapy for pancreatic cancer, and the main combination chemotherapy regimens are: 5-Fu ten MMC, 5-Fu ten MMC ten Streptozotoin (streptozotocin), 5-Fu + ADM ten MMC. Patient survival is also significantly prolonged with the MFA regimen.
MMC 10mg/m2 IV on day 1.
5-Fu 600mg/m2 IV day 182936.
ADM 30mg/m2 on day l29
Repeat efficacy at week 9: 39% for CR10PR
Regional chemotherapy for pancreatic cancer: Regional chemotherapy for pancreatic cancer is the administration of high doses of chemotherapeutic drugs through the main blood supply arteries of the pancreas. The rationale is: (1) the reason for the poor effect of systemic chemotherapy may be related to the fact that too few drugs enter the pancreatic cancer tissues when systemic chemotherapy is used, while regional chemotherapy allows high concentrations of chemotherapeutic drugs to enter the pancreatic cancer tissues directly; (2) the toxic side effects of systemic chemotherapy may be due to the systemic effects of chemotherapeutic drugs. The systemic toxic side effects of chemotherapeutic drugs limit the amount of chemotherapeutic drugs, while regional chemotherapeutic drugs acting first on pancreatic cancer tissues can significantly reduce the systemic toxic side effects and therefore increase the amount of chemotherapeutic drugs. In conclusion, regional chemotherapy can make chemotherapeutic drugs more targeted and increase the amount of chemotherapeutic drugs to improve the effect of chemotherapy and significantly reduce the toxic side effects of chemotherapeutic drugs.
Perioperative management
Patients with pancreatic cancer are often in poor general condition and radical surgery, especially pancreaticoduodenectomy, is highly traumatic with many bleeding complications and high surgical mortality, therefore, correct and positive perioperative management is crucial.
1.Improve the patient’s general condition before surgery
(1) strengthen nutrition to correct hypoproteinemia: it is advisable to give a high-protein, high-sugar, high-vitamin, low-fat diet supplemented with pancreatic enzymes and other digestive drugs (2) maintain water-electrolyte balance (3) supplement vitamin K. Patients often have varying degrees of liver impairment and severe obstructive jaundice because bile does not enter the intestine, so that fat-soluble vitamin K is not properly absorbed, resulting in insufficient synthesis of suspected blood enzyme K. Therefore, vitamin K should be injected from the time of admission to the hospital. (4) Control diabetes: The incidence of diabetes in pancreatic cancer patients is much higher than that of the general population. Once the examination is confirmed, ordinary insulin should be used to control blood glucose in the range of 7.2 to 8.9 mol/L urine glucose (+) to (-).
2, preoperative yellowing reduction: pancreatic cancer due to yellowing does not require routine yellowing reduction for jaundice for a short period of time, the general condition is still good digestive function, coagulation mechanism and renal function is still in the normal range, but if the general condition is poor bilirubin is higher than 342μmol/L fecal bilirubin negative jaundice for more than 2 weeks and increasingly heavy and with aura renal insufficiency should be considered. Specific methods to reduce yellowing include choledochostomy PTCD transduodenoscopy placement of nasobiliary drainage tube or bile-intestinal drainage tube
3.Prevention of post-surgical complications
(1) Prophylactic use of antibiotics: If there is no infection before surgery, there is no need to apply antibiotics prematurely, and a full dose of broad-spectrum antibiotics can be given intravenously 30 minutes before the start of surgery, and then add a dose for more than 4 hours.
(2) Respiratory preparation: postoperative pulmonary complications of pancreatic cancer are quite common. Preventive measures should be taken before surgery to strictly abstain from smoking, preferably for more than 2 weeks, and teach patients to perform deep chest breathing exercises to help prevent postoperative alveolar atrophy pulmonary infection and hypoxemia.
4. Intraoperative management should be strengthened: blood pressure must be kept stable, oxygen supply must be adequate, abdominal muscle relaxation and analgesia should be good, urine glucose and blood sugar should be monitored and controlled within a reasonable range, and pancreatic cancer patients often have potentially low coagulation function.
5.Postoperative treatment
(1) Continue to apply antibiotics
(2) prevent pancreatic fistula in addition to the management of pancreatic duct drainage and abdominal drainage can be used to inhibit the secretion of pancreatic fluid with growth inhibitor octapeptide can significantly reduce the chance of pancreatic fistula
(3) Reasonable nutritional support
(4) Pay attention to the management of drainage tubes and closely observe the drainage of the gastric bile duct, pancreatic duct and abdominal drainage to keep the flow of drainage accurately recorded and pay attention to the changes in its shape to solve problems at any time.