Optimal sequential therapy using tyrosine kinase inhibitors as the first-line treatment in patients with metastatic renal cell carcinoma: A nationwide multicenter study.

Objective: The purpose of the study was to identify the best sequence of therapy beginning with a tyrosine kinase inhibitor (TKI) as the first-line therapy for patients with metastatic renal cell carcinoma (mRCC) in terms of overall survival (OS), progression-free survival (PFS), and rates of discontinuation and adverse effects during the treatment period. Methods: This is a retrospective, nationwide multicenter study of patients with mRCC after diagnosis at 10 different tertiary medical centers in Korea from January 1992 to December 2017. We focused on patients at either "favorable" or "intermediate" risk according to the International mRCC Database Consortium criteria, and they were followed up (median 335 days). Finally, a total of 1409 patients were selected as the study population. We generated a Cox proportional hazard model adjusted for covariates, and the different therapy schemes were statistically tested in terms of OS as well as PFS. In addition, frequencies of discontinuation and adverse events were compared among the therapy schemes. Results: Of the primary patterns of treatment sequences (24 sequences), "sunitinib-pazopanib" and "sunitinib-everolimus-immunotherapy" showed the most beneficial results in both OS and PFS with significantly lower hazards than "sunitinib", which is the most commonly treated agent in Korea. Considering that the "TKI-TKI" structure showed relatively higher discontinuation rates with higher adverse effects, the overall beneficial sequence would be "sunitinib-everolimus-immunotherapy". Conclusion: Among several sequential therapy starting with TKIs, "sunitinib-everolimus- immunotherapy" was found to be the best scheme for mRCC patients with "favorable" or "intermediate" risks.