Author of

• 14704

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  P2.11 - Poster Session/ Palliative and Supportive Care (ID 230)

  • Event: WCLC 2015
  • Type: Poster
  • Track: Palliative and Supportive Care
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/08/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)

  • 14715

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    P2.11-011 - Utility of Tolvaptan and Demeclocycline in Addition to Systemic Chemotherapy for the Management of Hyponatraemia in Small Cell Lung Cancer (ID 1281)

    09:30 - 09:30  |  Author(s): R. Califano
    • Abstract

    Background:
    Hyponatraemia due to the syndrome of inappropriate anti-diuretic hormone (SIADH) occurs in 10-25% of small cell lung cancer (SCLC) patients. Management of SIADH includes review of medications, fluid restriction and increased solute intake in addition to commencing chemotherapy. The risk/benefit of the tetracycline derivative demeclocycline and the vasopressin receptor antagonist tolvaptan were recently questioned in a clinical practice guideline for hyponatraemia management (Spasovski, 2014). We sought to evaluate how demeclocycline and tolvaptan were used in addition to chemotherapy in the management of hyponatraemia in patients with SCLC and their effect on serum sodium prior to the publication of this guideline.
    
    Methods:
    A retrospective case-note review of 132 patients with SCLC treated at The Christie NHS Foundation Trust between 2009 and 2013 was undertaken to identify patients with serum sodium ≤132 mmol/L at diagnosis. Clinical and laboratory data were collected and change in sodium from nadir to peak values at day 7-14 and day 20-40 was calculated. Patients were divided in three groups: treated with chemotherapy alone, and chemotherapy plus demeclocycline or tolvaptan. Patients with complete data were included in the statistical analysis. Mean values were compared using an unpaired Students t-test.
    
    Results:
    Twenty seven patients (20%) had sodium ≤132mmol/L at diagnosis (mean 128 mmol/L, SD 3.9). Measurement of urine and plasma osmolality and urine sodium were performed in 6/27 (22%); thyroid function was measured in 6/27 patients and adrenal function in 4/27. Remaining patients were treated empirically. Patients receiving platinum based chemotherapy alone (12/27 patients receiving 1 to 6 cycles) had the highest mean sodium nadir of 128 mmol/L. Those receiving demeclocycline (13/27 patients) had a mean sodium nadir of 126 mmol/L. Patients receiving tolvaptan (6/27, 4 after prior demeclocycline) had the lowest mean sodium nadir of 121 mmol/L (p=0.0132 comparing with chemotherapy only group). Chemotherapy alone increased mean sodium from 128 mmol/L to 134 mmol/L by day 7-14 (p=0.0062) and 135 mmol/L by day 20-40 (p=0.0007). The addition of demeclocycline increased mean sodium from 126 mmol/L to 130 mmol/L (p=0.0527) and 132 mmol/L (p=0.0102) at the same time-points. The addition of tolvaptan increased mean sodium from a nadir of 121 mmol/L to 135 mmol/L at 7-14 days (p=0.0126) and 133 mmol/L at 20-40 days (p=0.0080). No significant toxicity of demeclocycline or tolvaptan were reported.
    
    Conclusion:
    Most cases of hyponatraemia were treated empirically as SIADH using demeclocycline and/or tolvaptan in over half of patients in addition to chemotherapy. Tolvaptan was used to treat patients with the lowest mean sodium most often following failure of demeclocycline. Despite this, these patients had peak sodium levels post treatment equivalent to those in other patients in this study. Clinician choice to treat patients with tolvaptan and/or demeclocycline in adition to chemotherapy was associated with a statistically and clinically meaningful improvement in serum sodium levels in all groups studied. Although this study is limited by the retrospective nature of the analysis, our group is using these data to produce guidelines on the management of hyponatraemia in SCLC to standardise patient management which will be prospectively evaluated.