Anemia in patients ≥ 75 years with metastatic clear cell renal cell carcinoma: an important poor prognostic factor in the international metastatic renal cell carcinoma database consortium model

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. Survival analyses were determined using a Kaplan–Meier method, and analyzed with a log-rank test. Results: Elderly patients categorized as favorable risk group based on the International Metastatic RCC Database Consortium (IMDC) stratification system were significantly lower. Among IMDC risk factors, the rate of anemia was significantly higher in elderly patients. No statistically significant benefit in progression free survival for first and second line treatment was observed, whereas improvements in overall survival as well as cancer specific survival were seen in patients aged < 75 years. 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. Furthermore, 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.