Post-nephrectomy recurrence appears to be associated with significantly shorter overall survival (OS) among patients with intermediate-high or high-risk renal cell carcinoma (RCC), resulting in a strong positive association between disease-free survival (DFS) and OS, according to research presented at the International Kidney Cancer Symposium (IKCS) 2021.
Investigators conducted a retrospective observational study using data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database between 2007 and 2016 to assess the association between DFS and OS in patients with newly diagnosed, completely resected, intermediate-high (pT2N0 Grade4/pT3N0) or high-risk (pT4N0/pTanyN1) RCC post-nephrectomy. They also compared mean monthly all-cause medical and pharmacy costs per patient between the recurrence and nonrecurrence cohorts.
Overall, 643 postnephrectomy RCC patients, 269 with recurrence and 374 without recurrence, were included in the study. Patient demographics and disease characteristics were well balanced across the cohorts. In both cohorts, the mean age was approximately 75 years, and most patients were White (each 86%).
Among patients with and without recurrence, 96.3% and 98.9% had intermediate-high risk RCC and 3.7% and 1.0% had high-risk RCC, respectively. Among patients with recurrence, 10.8% had locoregional recurrence and 89.2% had distant metastatic recurrence.
Among these patients with intermediate-high or high-risk RCC, those with postnephrectomy recurrence had significantly shorter OS compared with those without recurrence (median 2.5 years vs not reached; adjusted hazard ratio [HR], 6.0; 95% confidence interval [CI], 4.2-8.5; P <.0001).
The median postnephrectomy OS and DFS was 8.61 and 4.44 years, respectively. The investigators found a strong positive association between DFS and OS (Kendall’s τ, 0.70; 95% CI, 0.65-0.74; P <.001).
At each point in a landmark analysis, patients with recurrence had shorter subsequent OS compared with patients without recurrence. For patients with vs without recurrence, the median OS after each landmark following initial nephrectomy was 2.4 vs 9.7 years at 1 year (adjusted HR, 3.5), 4.5 vs not reached at 3 years (3.0), and 5.7 vs not reached at 5 years (2.7; all P <.001), respectively, and the 5-year survival rates after the corresponding landmark points were 37.0% vs 70.1% at 1 year, 42.3% vs 72.8% at 3 years, and 53.2% vs 78.6% at 5 years, respectively.
Patients with recurrence had significantly higher inflation-adjusted all-cause medical and pharmacy costs per patient per month compared with patients without recurrence, on average $4924 and $1387 higher, respectively (both P <.001).
“These findings demonstrate that in SEER longer DFS is prognostic of longer OS among patients with RCC following initial nephrectomy and suggest that DFS can be useful as a predictor of OS in the RCC adjuvant setting when OS data are immature,” concluded the investigators
Haas NB, Song Y, Willemann-Rogerio J, et al. Disease free survival (DFS) as a predictor of overall survival (OS) in localized RCC following first nephrectomy. Presented at IKCS 2021; November 5-6, 2021. Abstract E38.