Predictive Value of Neutrophils Count for Local Tumor Control After Chemoradiotherapy in Patients With Locally Advanced Pancreatic Carcinoma

PURPOSE

Baseline neutrophil count may predict overall survival (OS) in patients with locally advanced pancreatic cancer (LAPC).

METHODS AND MATERIALS

The international multicenter randomized LAP07 phase 3 trial has enrolled 442 patients with LAPC. We analyzed the prognostic value of both baseline neutrophilia (neutrophil count >7 g/L) and elevated or increasing neutrophil count as (1) neutrophilia or (2) increased absolute neutrophil count after induction chemotherapy versus baseline for OS, progression-free survival, and local control (LC). A Cox proportional hazard model was used to assess elevated or increasing neutrophil count status by randomly assigned treatment interactions for each endpoint.

RESULTS

Among the 442 patients, 47 patients (11%) with baseline neutrophilia had worse OS (median 8.9 vs 13.3 months; P = .01). After induction chemotherapy, among the 235 patients whose blood counts were available, 90 patients (38%) had elevated or increasing neutrophil count associated with poorer OS in univariate (median 14.4 vs 17.9 months; P = .001) and multivariate analysis (P = .004). Elevated or increasing neutrophil count was also predictive of a decreased benefit of chemoradiation therapy on LC. In 126 patients without elevated or increasing neutrophil count, 1-year LC was 80% in the chemoradiation arm versus 54% in the chemotherapy arm (P < .001; interaction test P = .015).

CONCLUSIONS

In this study, baseline neutrophilia and increased absolute neutrophil count were associated with worse OS in this large series of patients with LAPC. In addition, the counts were an independent prognosis factor and a strong predictive LC biomarker for chemoradiation therapy benefit. An assessment of neutrophils counts can help to improve the selection of patients who might benefit from chemoradiation therapy after induction chemotherapy.

Duration of therapy for locally advanced pancreatic cancer: Does it matter?

INTRODUCTION

Evidence-based recommendations on duration of multiagent systemic therapy for LAPC are lacking. Herein, we assess the impact of duration of combination systemic therapy on survival of patients with LAPC.

METHODS

The National Cancer Database was interrogated to identify patients with untreated LAPC diagnosed from 2004 to 2014. Patients treated with ≥ 1 month of multiagent chemotherapy (MAC) and ≥ 6 months of follow-up were included. Kaplan-Meier survival curves were generated to examine OS of each MAC duration group. Univariable and multivariable Cox proportional hazards regression was used to examine the association between OS with demographic and clinical variables. Statistical computations were performed using SAS Software Version 9.4.

RESULTS

Of the 3410 patients, 1114 met inclusion criteria. Median age was 64 years. Median treatment duration was 3.2 months (range 1-19.8). Median follow-up was 23.5 months (range 3-120). Median OS of all patients was 9.4 months (95% CI: 8.7-10.1). Median OS of patients receiving ≥ 1-4 months, >4-6 months and > 6 months of MAC was 8.4 months (95% CI: 7.7-9), 10.2 months (95% CI: 9-11.8), and 12.8 months (95% CI 11.6-16). Twelve-month survival was 37% for patients receiving ≥ 1-4 months, 43% for > 4-6 months, and 56% for > 6 months. Female sex (P = .02), higher median household income (P = .03), and longer duration of MAC (P < .001) were independently associated with improved OS following multivariable analysis.

CONCLUSION

This analysis in LAPC patients suggests that combination systemic therapy regimens of 6 months or more may optimize survival outcomes. Further investigation on the duration of systemic therapy question in LAPC is needed.