Summary.
The incidence of pancreatic cancer is increasing year by year, and it is expected that about 30,000 patients died from pancreatic cancer in the United States in 2006. Pancreatic cancer has become the fourth cause of cancer death in men in the United States, and its peak incidence is between 70 and 80 years old. According to statistics, the incidence of pancreatic cancer in Shanghai, China has increased 4 times in the past 20 years. This pancreatic cancer guideline only discusses exocrine tumors of pancreatic cancer and does not address endocrine tumors from islets and other tumors such as carcinoid tumors.
Risk factors and genetic predisposition.
Risk factors for pancreatic cancer include: smoking, increased body mass index, chronic exposure to harmful chemicals, (such as betanaphthylamine and benzidine) Families with a high incidence of pancreatic cancer, true familial hereditary pancreatic cancer is rare; about 5% of patients show a genetic predisposition. Other risk factors include diabetes, alcohol consumption, chronic pancreatitis, etc. Nowadays, it is gradually recognized that hyperglycemia and pancreatic cancer are mutually causal. Some studies have shown that the risk factors for pancreatic cancer in patients with chronic pancreatitis are actually associated with alcohol consumption, smoking and selection bias.
Principles of surgical treatment.
Diagnosis, management, and resectability assessment must involve multidisciplinary consultation (which includes imaging).
Evidence shows that surgeons and medical units that perform a high number of pancreatic procedures have superior surgical resection rates, mortality and complication rates. Therefore, it is recommended that surgery be performed by experienced surgeons and the specialization of pancreatic surgery in hospitals that are in a position to do so is advocated.
Diagnosis.
Symptoms, signs
The main symptoms of pancreatic malignancy include weight loss, jaundice, steatorrhea, pain, indigestion, nausea and depression. The possibility of pancreatic cancer should be considered in patients with diabetes mellitus or in patients over 50 years of age with sudden onset of type 2 diabetes mellitus with unusual manifestations such as abdominal symptoms and persistent weight loss.
Imaging
CT, ultrasound and MR are commonly used. Spiral CT has a 90% confirmation rate for pancreatic cancer. It includes obstructive jaundice and pancreatic mass, tumor liver, abdominal metastasis and macrovascular invasion. Endoscopic ultrasound is superior to CT in the evaluation of masses and large vessel invasion, and MRCP is highly recommended because of its ability to simultaneously visualize masses, bile ducts, pancreatic ducts, and peripancreatic vessels. ERCP or PTC cholangiography is performed in patients with obstructive jaundice.
Tumor-associated antigens
Tumor-associated antigens associated with pancreatic cancer include carcinoembryonic antigen (CEA), pancreatic antitumor antigen, tissue peptide antigen, CA125, and CA19-9. CA19-9 levels >100 U/ml are approximately 90% accurate in diagnosing pancreatic cancer. CA19-9 is commonly expressed in pancreatic and hepatobiliary diseases and many other malignancies. Therefore, it is not tumor-specific. However, elevated levels of CA19-9 are useful for differentiating pancreatic cancer from inflammatory disease of the pancreas. Moreover, serial decreases in CA19-9 levels are associated with survival in patients with pancreatic cancer after surgery or chemotherapy.
Pathological diagnosis
Preoperative ERCP pancreatic ductal cytobrush or biopsy; ultrasound endoscopy (preferred) or CT-guided fine-needle percutaneous biopsy; intraoperative excisional needle (corebiopsy) aspiration biopsy, or direct excisional tissue biopsy can be performed. However, it is not mandatory to obtain biopsy evidence of malignancy (positive) before performing the procedure. Although the need for histological diagnosis prior to surgery is not emphasized, it is mandatory prior to neoadjuvant chemotherapy.
Laparoscopy
Laparoscopy is a potentially useful tool in the diagnosis and staging of pancreatic cancer. It can detect peritoneal implant metastases missed by CT with liver metastases. Laparoscopy is of little significance in patients with pancreatic head cancer with biliary obstruction and no evidence of metastasis. In contrast, laparoscopy is recommended for additional staging in barely resectable lesions or with poor prognostic factors (e.g., significantly elevated CA19-9, large primary lesions, tumors in the tail of the pancreatic body).
Treatment.
Preoperative bile drainage
The effectiveness of perioperative yolk reduction surgery is controversial. Therefore, routine preoperative bile drainage is not emphasized. However, bile drainage procedures such as internal or external drainage or stenting are feasible in patients who have to postpone surgery due to malnutrition, sepsis, comorbidities, and neoadjuvant chemotherapy.
Surgical treatment
The only possible cure for pancreatic cancer is to remove the tumor and the surrounding pancreatic tissue. The manner and extent of surgery depends on the location and size of the tumor. However, only 20% of the lesions are resectable.
Determination of resectability
A resectable pancreatic tumor must have: no extra-pancreatic lesions; no direct invasion of the celiac artery or superior mesenteric artery by the tumor; no obstructive invasion of the superior mesenteric-portal vein by the tumor.
Resectable
Head/body/tail
1.No distant metastasis
2, clear and bright fat around celiac trunk and superior mesenteric artery
3. Superior mesenteric vein/portal vein is patent without infiltration
Possible resection
Head/body
4.Simple invasion of superior mesenteric vein/portal vein
5.Tumor adjacent to superior mesenteric artery
6.Gastroduodenal artery encircling
7.Tumor simply encircling the inferior vena cava
8.Superior mesenteric vein occlusion, if the proximal and distal veins are patent.
9.Colonic and colonic mesenteric invasion
caudal part
10.Infection of adrenal gland, colon or colonic mesentery, or kidney
11, Positive peripancreatic lymph node biopsy before surgery
Not resectable
Cephalic
1, distant metastasis (including abdominal trunk and/or para-aortic)
2, encapsulation of superior mesenteric artery, celiac trunk
3, occlusion of superior mesenteric vein/portal vein
4, Invasion or encirclement of the aorta, inferior vena cava
5, Infiltration of the superior mesenteric vein below the transverse colonic mesentery
Body
1, distant metastasis (including abdominal trunk and/or para-aortic)
2, Encapsulation of superior mesenteric artery, celiac trunk, hepatic artery
3.Superior mesenteric vein/portal vein occlusion
4, abdominal aortic invasion
Caudal
1, distant metastasis (including abdominal trunk and/or para-aortic)
2, Encasement of superior mesenteric artery, abdominal trunk
3.Invasion of ribs and vertebrae
Basic surgery for pancreatic cancer
The modality and scope of surgery depend on the site and size of the tumor. Commonly used surgical procedures include pancreaticoduodenectomy, pancreatic tail resection, middle pancreatic resection, total pancreatectomy and pancreatic head resection with preservation of duodenum.
Pancreaticoduodenectomy (Whipple’s procedure)
Extent of resection
Complete resection of the tumor (margin-negativeresection), the head of the pancreas (including the pancreatic hook), the neck, the associated organs (bile duct below the hepatic hilar, duodenum and part of the jejunum, part of the stomach) and the connective tissue and lymph nodes in the region. Avoid any residual tumor visible to the naked eye, including bile ducts, gastrointestinal, pancreatic cut margins, retroperitoneal connective tissues and lymph nodes. Combined resection of the invaded superior mesenteric-portal vein and the involved adjacent organs can be performed when negative resection of the incisional margin can be achieved. If there is any residual tumor tissue visible to the naked eye, it should be considered as a palliative resection. The presence of extensive retroperitoneal lymph node metastasis is a sign of systemic disease, and the combination of lymph node dissection does not change the prognosis at this time, and should also be considered as palliative resection.
Reconstruction method
There is no direct relationship between the mode of pancreaticoduodenectomy gastrointestinal reconstruction and the incidence of anastomotic leakage. The quality of the anastomosis is more important than the mode of anastomosis. Pancreaticogastric anastomosis and the various pancreatic-jejunal anastomoses: end-to-end, end-to-side, pancreatic duct-to-mucosa, and sleeve-in techniques are all effective and safe, with no difference in the incidence of postoperative pancreatic fistula. No single anastomotic technique is superior to the others, and ensuring the quality of the anastomosis and good blood supply to the anastomosis is the key to reducing the incidence of pancreatic fistula. There is no evidence that the use of santodine reduces the incidence of pancreatic fistula. Preservation of the pylorus of the pancreaticoduodenum may shorten the operative time, but there is a lack of evidence that preservation of the pylorus improves the quality of life and nutritional status of patients after resection.
Distal pancreatic resection
Pancreatic body-caudal resection including pancreatic body-caudal, spleen, intra-regional connective tissue, and lymph nodes. Mid-pancreatic resection including the neck and body of the pancreas with proximal closure of the pancreas and distal pancreatic-enteric anastomosis.
Extensive retroperitoneal lymph node dissection
The removal of lymph nodes as part of pancreaticoduodenectomy remains controversial. There is no evidence-based medical evidence that the addition of extensive retroperitoneal lymph node dissection to standard pancreaticoduodenectomy improves survival; therefore, regional lymph node dissection should not be a routine part of pancreaticoduodenectomy.
Superior mesenteric-portal vein resection and reconstruction
Prolonged survival has been reported in selected cases undergoing combined venous resection pancreaticoduodenectomy compared to palliative treatment, therefore combined venous resection is recommended selectively in cases where a negative marginal (marginCnegativeresection) result can be obtained. Revascularization includes the use of self and exogenous vessels.
Palliative surgery
Palliative pancreaticoduodenectomy or distal pancreatectomy may improve the quality of survival in some patients, but there is no clear evidence that it prolongs patient survival. Therefore, there is insufficient evidence to suggest that it should be routinely applied. Palliative care for patients with concomitant obstructive jaundice includes external drainage, internal bile-intestinal drainage, endoscopic or percutaneous percutaneous drainage and stenting. Bypass surgery is performed in patients with gastric outflow tract obstruction.
Abdominal sympathetic nerve inactivation
Chemotherapy and radiotherapy
Pre- and post-operative chemotherapy or/and radiotherapy for pancreatic cancer remains controversial and contradictory, with a slight advantage of Gemcitabine over 5-FU in improving survival. The efficacy of other agents is being evaluated.
Other adjuvant treatments
include radiofrequency tissue inactivation, cryopreservation, high-energy focused ultrasound, gamma-knife and biologic therapy, for which there is no clear evidence of prolonged survival.