Clinical outcome of advanced and metastatic renal cell carcinoma treated with targeted therapy: is there a difference between young and old patients?

BACKGROUND To assess whether the clinical outcome of advanced and metastatic renal cell carcinoma (mRCC) treated with targeted therapy differs between young and old patients. PATIENTS AND METHODS A total of 327 patients with advanced renal cell carcinoma and mRCC who received targeted therapy in two Chinese clinical centers were analyzed retrospectively. The patients were stratified into three groups: young (aged <45 years), middle-aged (aged 45-64 years), and old (aged ≥65 years). Overall survival (OS) and progression-free survival (PFS) curves were drawn using the Kaplan-Meier method, and Cox's proportional hazard regression model was used to compare OS and PFS within age groups. RESULTS There were no significant differences among young, middle-aged, and old groups in terms of OS (P=0.087), whereas PFS in the old group was significantly better than in the young and middle-aged groups (P=0.043). Both OS and PFS in the younger groups (aged <65 years) were significantly worse than in the old group (age ≥65 years; median OS, 28.1 vs 28.7 months [P=0.029]; median PFS, 11.4 vs 14 months [P=0.015]). No difference in OS or PFS was found between the young and middle-aged groups. After adjusting for sex, body mass index, smoking status, hypertension, diabetes mellitus, Eastern Cooperative Oncology Group score, history of cytokines, and Fuhrman grade, old age was an independent favorable prognostic factor for OS and PFS compared with younger age (<65 years) (OS, hazard ratio, 0.552 [95% confidence interval, 0.329-0.828; P=0.006]; PFS, hazard ratio, 0.584 [95% confidence interval, 0.401-0.850; P=0.005]). CONCLUSION Younger patients with advanced renal cell carcinoma and mRCC receiving targeted therapy have a poorer prognosis compared with old patients. These results remain to be examined in prospective cohorts.