Survival outcomes of double- and triple-sequential targeted therapy in patients with metastatic renal cell carcinoma: a retrospective comparison

OBJECTIVE: To evaluate the progression-free survival (PFS) and overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) treated with double- and triple-sequence targeted therapy (TT) using tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin inhibitors (mTORi). MATERIALS AND METHODS: Records of 292 patients with mRCC, treated with TT between January 2005 and July 2015, were analyzed retrospectively. Kaplan-Meier and log-rank analyses were used to calculate and compare the total PFS (tPFS) and OS when patients underwent double- or triple-TT using TKIs or mTORi. RESULTS: Eighty-one (27.7%) patients who underwent second-line TT were enrolled; 30 (10.3%) of whom underwent third-line TT. The tPFS and OS of double-TT using TKI-mTORi (5.4 and 30 months, respectively) were significantly better compared with TKI-TKI (0.3 and 2 months) or mTORi-TKI (2 and 6 months) (p <0.001). For triple-TT, the tPFS and OS of TKI-mTORi-TKI (22.8 and 25 months, respectively) were significantly superior compared with those for TKI-TKI-mTORi (4 and 9 months) (p <0.05). For patients with intermediate-risk according to the Heng or Memorial Sloan-Kettering Cancer Center risk models, TKI-mTORi was associated with a significantly longer tPFS and OS compared with TKI-TKI [expect for OS in the Heng group (p = 0.086)]. For the triple TT group, TKI-mTORi-TKI resulted in improved tPFS and OS compared with TKI-TKI-TKI or TKI-TKI-mTORi (p <0.05). CONCLUSION: In patients with mRCC, sequential administration of TKI-mTORi led to a significantly superior tPFS compared with any other TT sequence. By contrast, OS did not differ significantly according to TT sequence.