Hyponatremia in Cancer Patients Hospitalized in a Palliative Care Department: A Cross-Sectional Analysis

Hyponatremia is frequent in cancer patients, as many studies carried out in these patients have shown. However, there are only a few studies carried out at the end of life and in palliative care. The aim of this study was to determine the prevalence of hyponatremia in cancer patients in the palliative care department of an oncology center and its association with survival. The study included the first 300 patients hospitalized in the palliative care department in 2017. Survival was measured from the day of hospitalization until death. Serum sodium was measured in 170 (59%) patients. The median serum concentration was 135 mmol/L (109 to 145). Among 91 (54%) patients, serum sodium was within the normal range, 59 (35%) had mild hyponatremia, 13 (8%) had moderate and seven (4%) had profound hyponatremia. The median survival was 13 days (1 to 1020). Serum sodium was not significantly associated with survival (p = 0.463). Regarding other variables, the Eastern Cooperative Oncology Group performance status was significantly associated with survival, while gender, age, primary cancer and number of metastatic sites were not. Hyponatremia, mainly mild and moderate, was found in almost half of the patients included in this study. However, unlike other studies, hyponatremia was not associated with a poorer prognosis. Hyponatremia is common in cancer patients receiving palliative care but did not seem to influence survival.