CA19-9 Reduction After 4 Months of Treatment Is a Prognostic Factor for Locally Advanced Pancreatic Cancer.

ABSTRACT

BACKGROUND/AIM: Carbohydrate antigen 19-9 (CA19-9) levels may aid in the determination of subsequent treatment in patients with unresectable locally-advanced pancreatic cancer (LAPC) treated with chemotherapy. However, the relationship between the timing and magnitude of CA19-9 changes and clinical outcomes remains unclear. This study was conducted to identify the timing and magnitude of CA19-9 changes, which are most strongly associated with outcomes in LAPC patients. PATIENTS AND METHODS: We retrospectively analyzed consecutive LAPC patients treated with gemcitabine plus nab-paclitaxel (GnP) or modified FOLFIRINOX (mFFX) as the first-line chemotherapy between March 2014 and December 2018 in our hospital. Multivariate analyses were performed to identify prognostic factors of chemotherapy in LAPC. RESULTS: Ninety-four patients were included (GnP/mFFX 72/22). The median overall survival was 20.3 months, and the median progression-free survival was 8.8 months. CA19-9 values before treatment did not affect prognosis. However, CA19-9 <100 U/ml or more than a 70% reduction in CA19-9 four months after commencing treatment was associated with a good prognosis (hazard ratio=0.17; 95% confidence interval=0.09-0.33; p<0.01). CONCLUSION: CA19-9 values 4 months after commencing treatment are a significant prognostic factor in LAPC patients undergoing chemotherapy.