Impact of low and high body mass index on predicting therapeutic efficacy and prognosis in patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors.

ABSTRACT

OBJECTIVE: To evaluate the significance of both low and high body mass index (BMI) as a biomarker in first-line tyrosine kinase inhibitors (TKIs) for metastatic renal cell carcinoma (mRCC). METHODS: The oncological outcome of 235 patients with mRCC treated with TKI from 2007 to 2018 was reviewed retrospectively. All patients received first-line TKI as therapy. We analyzed the relationship between BMI (low and high) and disease control rate. The primary outcome was progression free survival and overall survival, and the association between BMI and survival prognosis was evaluated. RESULTS: The median BMI was 22.5 kg/m2 , and 25 patients (10.7%) had a low BMI (<18.5 kg/m2 ), 158 patients (67.2%) had a normal BMI (18.5-25 kg/m2 ), and 52 patients (22.1%) had a high BMI (≥ 25 kg/m2 ). Patients in the low BMI group had a significantly lower disease control rate, whereas patients in the high BMI group had a significantly higher disease control rate (p = 0.002 and p = 0.030, respectively). A log-rank test showed prognosis to be significantly poorer in the low BMI group and to be significantly better in the high BMI group than that in the normal BMI group. Multivariable Cox regression analysis showed that low BMI was an independent indicator of poor prognosis, whereas high BMI was an independent indicator of favorable prognosis. CONCLUSION: We showed the impact of both low and high BMI on predicting therapeutic efficacy and prognosis in mRCC patients treated with TKI.