SESSION TITLE: Lung Cancer Posters
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM
PURPOSE: To assess the incidence and prognostic importance of hyponatremia (HN) in lung cancer (LC).
METHODS: This retrospective cohort analysis combined data from the Henry Ford Health System electronic medical record, tumor registry, and administrative databases. Adults diagnosed with incident LC 2002-2010 were selected if they had ≥1 administration of chemo/radiation therapy ≤6 months from diagnosis, met continuous enrollment thresholds, and did not experience hypovolemic HN post index. Hypervolemic or euvolemic HN incidence (serum sodium ≤135 mEq/L) was measured per 1000 person-years (/1000 PY) of observation and classified as mild (131-135), moderate (125-130), or severe (<125) based on the lowest observed value. A Cox proportional hazards model assessed the prognostic value of HN as a time-varying covariate on overall survival (OS) and progression-free survival (PFS) controlling for age, gender, race, income, histology, stage, and performance status at diagnosis.
RESULTS: 203 patients were eligible (55% male; mean [SD] age 64±11.6 years, 61% Caucasian). Mean (SD) follow-up was 16±21 months; 89% had non-small cell LC (NSCLC; 49% adenocarcinoma, 28% squamous cell), and 49% had metastatic disease at diagnosis. HN episodes (n=348) occurred in 155 patients (76.4%) at a rate of 1141/1000 PY (95% CI, 1015-1280) in patients with NSCLC and 3618/1000 PY (95% CI, 2718-4720) in small cell LC (SCLC). In patients with NSCLC and SCLC, respectively, median time to first hyponatremia episode was 40.5 and 16.0 days and 26.7% and 43.5% patients had ≥1 moderate/severe HN episode. In NSCLC and SCLC, respectively, median OS was 260 and 257 days; median PFS was 139 and 136 days. In this model, hazard ratio (95% CI, P) in the HN group was 2.9 (1.8-5.0; P<0.0001) for OS and 1.4 (0.9-2.1; P=0.11) for PFS.
CONCLUSIONS: Incidence of HN after diagnosis with LC is high in both SCLC and NSCLC, with first onset occurring within 40 days for half of all patients. The occurrence of hypervolemic or euvolemic HN after cancer diagnosis is independently associated with significantly poorer survival. Clinicians should be aware of this HN incidence and its association with worse survival.
CLINICAL IMPLICATIONS: Selective vasopressin V2-receptor antagonists are now available as targeted therapy for treatment of non-hypovolemic HN. Further investigations are warranted to see if HN resolution translates into better survival rates and if correction of HN with targeted therapy improves OS.
DISCLOSURE: Jorge Castillo: Consultant fee, speaker bureau, advisory committee, etc.: Honoraria, Otsuka America Pharmaceutical, Inc., Consultant fee, speaker bureau, advisory committee, etc.: Consultant/Advisory fee, Otsuka America Pharmaceutical, Inc. Ilya Glezerman: Consultant fee, speaker bureau, advisory committee, etc.: Consultant/Advisory fees, Otsuka America Pharmaceutical, Inc., and Amgen Inc., Grant monies (from industry related sources): Research funding, Amgen Inc. Susan Boklage: Employee: Employee, Otsuka America Pharmaceutical, Inc. Lois Lamerato: Grant monies (from industry related sources): Research funds, Outcomes Research Solutions, Inc., eMAXHealth, Policy Analysis, Inc., and Pfizer Joseph Chiodo: Employee: Employee, Otsuka America Pharmaceutical, Inc. Beni Tidwell: Grant monies (from industry related sources): Research funds, Otsuka America Pharmaceutical, Inc. Kathy Schulman: Grant monies (from industry related sources): Research funds, Otsuka America Pharmaceutical, Inc.
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