Ki67 and P53 in Relation to Disease Progression in Metastatic Pancreatic Cancer: a Single Institution Analysis

We investigated the expression patterns of Ki67 and p53 in metastatic pancreatic adenocarcinomas and analyzed their relationship with disease progression-free survival (PFS) and overall survival (OS) in the overall study population and in patients treated with a gemcitabine-containing chemotherapy versus FOLFIRINOX chemotherapy. Patients with histologically confirmed stage IV adenocarcinoma of the pancreas treated at AUBMC were included after obtaining institutional review board approval (IRB ID: IM.ST.05). The ROC was plotted to identify the threshold Ki-67, p53 and CA19-9 value for disease progression, the identified value was further used in Kaplan Meier curves to compare PFS for both groups (gemcitabine versus FOLFIRINOX). A value of p<0.05 was considered significant in all analyses. On univariate analysis, patients who had a Ki-67>12.5% or a p53>15% had significantly shorter PFS (p=0.034 and p=0.016, respectively). This effect was restricted to Gemcitabine or gemcitabine-combination treated patients. A decrease in CA19-9 levels 6-8weeks after chemotherapy of >58% had significantly longer PFS (p=0.027). On multivariate analysis after controlling for grade, age and P53, Ki-67 remained significant, for every one unit increase in Ki-67 the progression risk increases by 1.017 times. Our study highlights the negative impact of high P53 expression and Ki67 proliferation index on PFS in patients with metastatic pancreatic cancer.