Prognostic value of pre-operative serum MUC4 levels for predicting recurrence of pancreatic cancer

Abstract

15160 Background: The human transmembrane mucin MUC4 is aberrantly expressed in approximately 75% of pancreatic ductal adenocarcinomas, but not in normal pancreatic tissue. Preliminary data suggests serum MUC4 levels may have a diagnostic utility. Hence, we sought to determine if pre-operative MUC4 levels have a prognostic value in pancreatic adenocarcinoma. Methods: A database of MUC4 samples collected under an IRB-approved protocol was queried for subjects with pre-operative MUC4 levels. MUC4 assays were performed using RT-PCR. Descriptive statistics were used to summarize the disease and treatment characteristics of the patients. A level of 0.01 (median) was used to divide patients into high and low MUC4 groups. Kaplan-Meier method was used to summarize the time to event distributions for groups defined by MUC4 levels. Log-rank test was used to compare the time to event distributions between two groups. Results: Seventeen patients (eleven males - 65%) were identified, with a mean age of 65.8 yrs (range: 46 - 76 years) were identified. Pathologic staging was T2/T3 in 95%, 9 pts (53%) had N1 disease, while 15 patients (88%) had stage II disease. All but one received adjuvant therapy with chemotherapy (5FU ± gemcitabine) ± radiation. Patient, disease and treatment characteristics were similar in patients with low MUC4 levels (n=9) and high MUC4 levels (n=8). At a median follow-up of 1.8 years, 13 (77%) experienced disease recurrence and 14 (82%) died. There was no significant association between MUC4 levels and the risk of disease recurrence or death (p>0.9; p = 0.1, respectively). The one- year probabilities for relapse free survival (RFS) and overall (OS) were 0.9 (95% CI: 0.68 - 1.00) and 1 (95% CI: 1 - 1) for patients with low levels and 0.5 (95% CI: 0.15 to 0.85) and 0.63 (95% CI: 0.29 to 0.96) respectively, for subjects with high levels. Conclusions: Although these differences were not statistically significant, the group with high MUC4 levels appears to have higher risk features such as higher stage, regional lymph node disease and older age. Patients with high MUC4 levels had a trend towards higher risk of relapse or death. No significant financial relationships to disclose.