Hypothyroidism with Sunitinib Therapy and Its Correlation with Survival Outcomes in Advanced Renal Cell Carcinoma Patients

Objectives: Hypothyrodism is a common side effect of sunitinib therapy. However, few studies investigated the correlation between SUN induced hypothyroidism and efficacy of sunitinib in metastatic renal cell carcinoma patients(mRCC). Methods: We retrospectively reviewed 171 mRCC patients who received Sunitinib therapy. Eligibility criteria included receipt of first line therapy with SUN and no known history of hypothyroidism.We investigated the progression free survival and its correlation with SUN induced hypothyroidism. Results: In a median follow up of 60 months, male gender, current or ex-smoker status, side effect of hypothyroidism after sunitinib use, and palliative radiotherapy treatment were associated with better PFS. Hypothyroidism were not correlated with gender (p=0.222, r=-0.094), smoking status (p=0.343, r=0.076), or palliative radiotherapy (p=0.984, r=-0.002). Median PFS were 13.8 (95% CI: 4.3-19.0) months in hypothyroid (HY) group, and 5.1 (95% CI: 4.6-6.5) months in euthyroid (EU) group (p=0.017). 1y-PFS rates were 52.4% in HY and 17% in EU groups. In patients with clear cell histology (n=152), median PFS were 13.0 (95% CI: 9.2-16.8) months in HY group, and 5.7 (95% CI: 4.9-6.6) months in EU group (p=0.054). 1y-PFS rates were 52.6% in HY group, and 16.5% in EU group. Conclusion: Acquired hypothyroidism with sunitinib therapy is consistent with better outcomes in terms of progression free survival. Abstract