Author of

• 18718

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  P3.05 - Poster Session with Presenters Present (ID 475)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Palliative Care/Ethics
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 18732

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    P3.05-014 - Evaluation of Hyponatraemia in Lung Cancer Patients: A U.K. Teaching Hospital Experience (ID 4098)

    14:30 - 14:30  |  Author(s): S. Mascall
    • Abstract

    Background:
    Hyponatraemia, defined as a serum Na of <135mEq/L, is the commonest electrolyte abnormality in oncology practice. Among cancer patients, it occurs most frequently in small cell lung cancer(SCLC) and is due to inappropriate antidiuretic hormone secretion (SIADH), a paraneoplastic syndrome. The incidence of SIADH in SCLC is 11-15%. We describe the demographics, oncological management and response of hyponatraemia to oncological treatment modalities in hospitalised patients with lung cancer in a large inner-city teaching hospital.
    
    Methods:
    We retrospectively analysed the serum sodium levels in all lung cancer patients admitted to a teaching hospital in the West Midlands between 2007-2013. Data was collected on baseline demographics, histology, tumour stage and grade of hyponatraemia. Mild hyponatraemia was defined as a serum sodium between 130-135mEq/L, moderate between 125-129mEq/L, and severe as <124mEq/L.
    
    Results:
    182 (108 male; 74 female) patients with lung cancer and documented hyponatraemia were hospitalised between 2007-2013. Median age of patients was 69.2 years (range 33-92 years). 119(65%) had mild, 58(32%) moderate and 5(3%) severe hyponatraemia. 74(40%) were adenocarcinomas , 58(32%) squamous carcinomas, 43(24%) SCLC and 7(4%) had unspecified non small cell lung cancer. 89(49%) had metastatic disease at diagnosis. 18/43 (42%) small cell, 14/58 (33%) squamous , 23/74 (31%) adenocarcinoma patients had moderate to severe hyponatraemia. 132(74%) of this cohort had active oncological treatment: 93(51%) chemotherapy, 25(14%) radiotherapy, 17(9%) surgery whilst 47(26%) had best supportive care. 28(15%) had a biochemical response to treatment, 11(39%) of these patients were adenocarcinomas, 10(36%) squamous carcinomas and 7(25%) SCLC.
    
    Conclusion:
    Hyponatraemia in lung cancer patients is widely distributed in various age groups and histological subtypes. Among those admitted with hyponatraemia, severe cases (<124mEq/L) were rare. Higher rates of SIADH are seen in SCLC than in any other malignancy and our data confirmed that, proportionately, more SCLC patients had moderate - severe hyponatremia than non small cell lung cancer patients. Hyponatraemia does respond to active oncological treatment including chemotherapy, radiotherapy and surgery. Although historically, hyponatraemia is considered as a poor prognostic marker, this should not preclude active oncological management. Asymptomatic patients with SIADH have been managed initially by fluid restriction but patient compliance is usually poor. Older medications such as demeclocycline, urea and lithium are limited by variable efficacy, poor palatability and/or toxicity, thus underscoring the need for new approaches. Tolvaptan, a new vasopressin receptor antagonist, can improve hyponatraemia due to SIADH. Further studies are needed to evaluate the prognostic value of hyponatraemia and it’s treatment in cancer patients.