Clinical Characteristics and Prognosis of Elderly Small Cell Lung Cancer Patients Complicated with Hyponatremia: A Retrospective Analysis

Aim: This study was designed to evaluate the clinical characteristics and prognosis of elderly small cell lung cancer (SCLC) patients complicated with hyponatremia, thus providing increased attention for appropriate intervention and improving outcomes in symptomatic subjects. Patients and Methods: The clinical data of 320 patients with SCLC in the Yuhuangding Hospital from March 1st, 2006, to March 1st, 2012, were studied retrospectively. The prognosis and possible association with hyponatremia was investigated. Results: The incidence rate of hyponatremia in SCLC was 46.56% (149/320). The mean survival time was 1.10 +/- 0.42 years in patients with normal values and 0.83 +/- 0.35 years in patients with subnormal serum sodium. In the hyponatremia group, the mean survival time of corrected hyponatremia patients was 0.91 +/- 0.42 years, which was significantly longer than uncorrected hyponatremia patients whose mean survival time was 0.68 +/- 0.26 years (t=2.75, p<0.05) after symptomatic treatment. The mean survival time of the normal group and the hyponatremia group in elderly patients had a tendency to decrease when compared to another group of patients younger than 60 years old. Hyponatremia at 1- and 3-year follow-up was associated with worse survival rates (p<0.05). Conclusion: The severity of hyponatremia has unfavorable prognostic impacts. Elderly SCLC patients with hyponatremia are difficult to cure and associated with significantly shorter survival, especially in the uncorrected group. It is important that the cause of the hyponatremia is diagnosed at an early stage and precise medical treatment is provided.