Long Term Survivors with Metastatic Pancreatic Adenocarcinoma Treated with Gemcitabine: a Retrospective Analysis

Background: Metastatic pancreatic adenocarcinoma has a short median overall survival (OS) of 5-6 months. However, a subgroup of patients survives more than 1 year. We analyzed the survival outcomes of this subgroup and evaluated clinical and pathological factors that might affect survival durations.

Methods: We identified 20 patients with metastatic or recurrent pancreatic adenocarcinoma who received single-agent gemcitabine and had an OS longer than 1 year. Baseline data available after the diagnosis of metastatic or recurrent disease was categorized as: 1) clinical/demographic data (age, gender, ECOG PS, number and location of metastatic sites); 2) Laboratory data (Hematocrit, hemoglobin, glucose, LDH, renal and liver function and CA19-9); 3) Pathologic data (margins, nodal status and grade); 4) Outcomes data (OS, Time to Treatment Failure (TTF), and 2 year-OS). The lowest CA19-9 levels during treatment with gemcitabine were also recorded. We performed a univariate analysis with OS as the outcome variable.

Results: Baseline logarithm of CA19-9 and total bilirubin had a significant impact on OS (HR = 1.32 and 1.31, respectively). Median OS and TTF on gemcitabine were 26.9 (95% CI = 18 to 32) and 11.5 (95% CI = 9.0 to 14.3) months, respectively. Two-year OS was 56.4%, with 7 patients alive at the time of analysis.

Conclusion: A subgroup of patients with metastatic pancreatic cancer has prolonged survival after treatment with gemcitabine. Only bilirubin and CA 19-9 levels were predictive of longer survival in this population. Further analysis of potential prognostic and predictive markers of response to treatment and survival are needed.