Evaluation of clinicopathological variables and survival
Clinicopathological variables studied included 14 factors: sex, age at
surgery, preoperative serum CA19-9, preoperative serum carcinoembryonic
antigen(CEA), preoperative serum CA242, tumor location, type of surgery,
TNM stage,T stage, N stage, histology grade, lymphovascular invasion,
perineural invasion and postoperative adjuvant chemotherapy.
The levels of preoperative serum tumor markers (CA19-9, CEA and CA242)
were detected within 1 week before surgery. The normal upper limits of
serum tumor markers were adopted as follows: CA19-9 (37.0 U/ml), CEA
(5.0 ng/ml) and CA242 (20 U/ml). In this study, all patients with total
bilirubin ≥ 250mmol/L were treated with percutaneous transhepatic
biliary drainage or endoscopic retrograde biliary drainage. After
biliary darinage, the level of preoperative serum CA19-9 was detected
again.
The pathological diagnosis was established by two professional
pathologists. Tumors were staged according to the 8thedition of AJCC TNM staging of pancreatic cancer. The histology grade
were classified into two groups based on the degree of tumor
differentiation: low grade, including well or moderately differentiated
adenocarcinoma; and high grade, including poorly differentiated or
undifferentiated adenocarcinoma. Lymphovascular infiltration (LVI) was
referred to as blood vessel and lymphatic invasion. Perineural invasion
is an infiltrative process of peripheral nerves by the primary neoplasm
within the immediate vicinity. Patients who received more than three
cycles of postoperative adjuvant chemotherapy were defined as
chemotherapy group.