Anemia in patients aged ≥75 years with metastatic clear cell renal cell carcinoma: An important IMDC prognostic factor for systemic therapy.

Abstract

e16524 Background: Due to an increase in life expectancy, the incidence of metastatic renal cell carcinoma (mRCC) in patients aged ≥75 years has been increasing. In this study we investigated the characteristics before treatment and the outcomes of systemic therapies for patients aged ≥75 years with mRCC and compared the results with those for patients aged < 75 years in order to determine whether differences in age influenced survival. Methods: A total of 206 consecutive Japanese patients with mRCC, including 47 patients aged ≥75 years, who received systemic therapy were included. Clinical data from medical records were retrieved and analyzed retrospectively. Differences of several factors between the two groups were analyzed by the Chi-squared and Wilcoxon tests. Matching and balancing of the empirical distributions were performed by logistic regression analyses. Survival analyses were determined using a Kaplan–Meier method, and analyzed with a log-rank test. P values less than 0.05 were judged as statistically significant. Results: Elderly patients categorized as favorable risk group based on the International Metastatic RCC Database Consortium (IMDC) stratification system were significantly lower (p = 0.0241). Among IMDC risk factors, the rate of anemia was significantly higher in elderly patients (p = 0.006). No statistically significant benefit in PFS for first (p = 0.2183) and second line treatment (p = 0.2219) was observed, whereas improvements in OS (p = 0.0082) as well as CSS (p = 0.0083) were seen in patients aged < 75 years. Furthermore, mRCC patients aged ≥75 years tend to receive BSC instead of second line active treatment. To determine the impact of higher rates of IMDC intermediate/poor risk group in patients aged ≥75 years, we used propensity score matching using IMDC risk stratification to minimize potential bias. After propensity score matching, the well-matched 46 patients in each group demonstrated similar OS (p = 0.203) and CSS (p = 0.172). Conclusions: For mRCC patients aged ≥75 years, a higher proportion of base line anemia, which resulted in higher rates of IMDC intermediate/poor risk, would be responsible for shorter OS/CSS. In addition, mRCC patients aged ≥75 years tend to receive BSC instead of second line active treatment. Overcoming under-treatment in elderly patients might help to prolong survival in mRCC.