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 leading 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 inherited pancreatic cancer is rare; about 5% of patients show a genetic predisposition. Other risk factors include diabetes, alcohol consumption, and chronic pancreatitis. It is now 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 a multidisciplinary (which includes imaging) consultation.
Evidence shows that surgeons and medical units that perform a high number of pancreatic procedures have an advantage in 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 have the means 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, B ultrasound, 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 cutting needle (core biopsy) 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 histologic diagnosis prior to surgery is not emphasized, histologic diagnosis is required 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).
Staging of pancreatic cancer lesions
American Joint Committee on Cancer (AJCC), TNM staging of pancreatic cancer (2002)
Staging
T
N
M
IA
T1
N0
M0
IB
T2
N0
M0
IIA
T3
N0
M0
IIB
T1-T3
N1
M0
III
T4
Any N
M0
IV
Any T
Any N
M1
Primary tumor(T) Staging
TX Primary tumor could not be evaluated
T0 No evidence of primary tumor
Tis carcinoma in situ*
T1 Tumor confined to pancreas, maximal diameter ≤2cm
T2 Tumor confined to the pancreas, maximal diameter >2cm
T3 Tumor involvement beyond the pancreas but not involving the celiac trunk and superior mesenteric artery
T4 Tumor involving the celiac trunk or superior mesenteric artery (primary tumor cannot be removed)
* This also includes PanInIII classification
Regional lymph nodes (N)
NX Regional lymph nodes cannot be evaluated
N0 No regional lymph node metastasis
N1 with regional lymph node metastasis
Distant metastasis (M)
MX Distant metastasis could not be evaluated
M0 No distant metastasis
M1 with distant metastasis
Histopathological staging
95% of tumors of epithelial origin are ductal adenocarcinomas
l Severe ductal dysplasia/carcinoma in situ (PanIn III, pancreatic intraepithelial neoplasia)
l Ductal adenocarcinoma
l Mucinous non-cystic carcinoma
l Indolent cell carcinoma
l Adenophilic carcinoma
l Undifferentiated carcinoma (spindle and giant cell type; small cell type)
l Mixed ductal endocrine carcinoma
l Osteoblast-like giant cell tumor
l Plasmacytoid cystic adenocarcinoma
l Mucinous cystic adenocarcinoma
l intraductal papillary mucinous carcinoma with or without invasion (IPMN)
Adenoid cell carcinoma
l Adenoid cystic adenocarcinoma
l mixed alveolar endocrine carcinoma
l pancreaticoblastoma
l solid pseudopapillary optic nerve carcinoma
l Cross-border (unspecified potentially malignant) tumors (moderately poorly differentiated mucinous cystic tumor; moderately poorly differentiated intraductal papillary mucinous tumor; solid pseudophakic papillary tumor)
l Other
Histological grading(G)
GX Cannot determine the degree of differentiation
G1 Highly differentiated
G2 Moderately differentiated
G3 Hypodifferentiated
G4 Undifferentiated
Treatment.
Preoperative bile drainage
The effectiveness of perioperative yolk reduction surgery is controversial. Therefore, preoperative bile drainage is not routinely 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, superior mesenteric artery; and no obstructive invasion of the superior mesenteric-portal vein due to the tumor.