A retrospective study of predictive factors for unexpectedly prolonged or shortened progression-free survival and overall survival among patients with metastatic renal cell carcinoma who received first-line targeted therapy

Background: To identify predictors of prolonged or shortened progression-free survival (PFS) and overall survival (OS) among patients with metastatic renal cell carcinoma (mRCC) who received first-line targeted therapies. Methods: This retrospective study included 146 patients with mRCC who were treated during 2007-2015. These patients were divided into a group with the worst response (WG), an expected group (EG), and a group with the best response (BG), based on their PFS (<= 3 monthsnths, 3-18 monthsnths, and >18 monthsnths, respectively) and OS (<1 year, 1-3 years, and >3 years, respectively). To identify significant predictive factors, the BG and WG were compared to the EG using the Memorial Sloan Kettering Cancer Center and Heng risk models. Results: The overall PFS and OS were 9.3 months and 16.4 months, respectively. The median PFS for the WG (41.8 %), EG (45.9 %), and BG (12.3 %) were 2.7 months, 9.3 months, and 56.6 months, respectively, and the median OS for the WG (45.9 %), EG (35.6 %), and BG (18.5 %) were 5.5 months, 21.6 months, and 63.1 months, respectively; these outcomes were significantly different (p < 0.001). Nephrectomy (odds ratio [OR]: 7.15) was a significant predictor of PFS in the BG, and the significant predictors of OS in the BG were MSKCC intermediate risk (OR: 0.12), poor risk (OR: 0.04), and a disease-free interval of < 1 year (OR: 0.23) (all, p < 0.05). Anemia (OR: 3.25) was a significant predictor of PFS in the WG, and the significant predictors of OS were age (OR: 1.05), anemia (OR: 4.13), lymphocytopenia (OR: 4.76), disease-free interval of < 1 year (OR: 4.8), and synchronous metastasis (OR: 3.52) (all, p < 0.05). Conclusion: We identified several significant predictors of unexpectedly good and poor response to first-line targeted therapy among patients with mRCC.