Long-Term Survivors in Metastatic Pancreatic Ductal Adenocarcinoma: A Retrospective and Matched Pair Analysis.

ABSTRACT

BACKGROUND: Metastatic pancreatic ductal adenocarcinoma (mPDAC) is an aggressive malignancy with a median overall survival (OS) of between 8 and 11 months. However, a significant number of patients experience a longer survival, more than 18 months. The aim of this study was to describe the "long-term survivor" population and to evaluate clinical and pathological factors that might affect survival. MATERIALS AND METHODS: All patients with mPDAC diagnosed in the Centre Leon Bérard (Lyon, France) between January 2010 and June 2015 and who survived more than 18 months were identified. They were compared with a control cohort matched on age, sex, performance status, stage at diagnosis, primary tumor localization, treatment, and liver metastasis. Their clinical features, treatment modalities, and outcomes were analyzed. RESULTS: A total of 94 patients were included, 47 in each cohort. Both cohorts had identical characteristics as follows women (51%), performance status ≤1 (95.7%), median age at diagnosis (60 years), and metastasis at diagnosis (83%). Median OS was 26.87 months (95% confidence interval [CI] 23-31.08) in the long-term survivor group (LS group) and 9.79 months (95% CI 5.75-11.86) in the control group (C group). Potential factors of long-term survival were explored with a logistic model (LS group vs. C group). Three factors were identified as significant prognostic factors in the univariate analysis: lymphopenia (odds ratio [OR] ref yes = 0.26), neutrophil-to-lymphocyte ratio (NLR; OR ref >5 = 0.31), and peritoneal carcinomatosis (OR ref yes = 0.40). NLR was the only remaining factor in our backward selection procedure. CONCLUSION: A significant subset of patients with mPDAC can achieve long-term survival (≥18 months) in 2018. We identified low NLR as a significant prognostic factor associated with long-term survival in mPDAC. IMPLICATIONS FOR PRACTICE Metastatic pancreatic ductal adenocarcinoma (mPDAC) is one of the most lethal types of cancer. A subset of patients with mPDAC can achieve long-term survival (≥18 months) with a modern chemotherapy regimen, such as FOLFIRINOX or gemcitabine/nab-paclitaxel. We identified low neutrophil-to-lymphocyte ratio (NLR) as a significant prognostic factor associated with long-term survival in mPDAC. Prognostic factors such as NLR might allow accurate selection of patients with mPDAC in order to consider individual therapeutic approaches. NLR should be used as a stratification factor in clinical trials.