Adverse effects of androgen deprivation and the limits of national tumor registries

Does partial nephrectomy result in a durable overall survival benefit in the Medicare population?

PURPOSE

We assessed whether the impact of partial nephrectomy and radical nephrectomy on overall mortality differed by patient age in a Medicare population undergoing surgery for T1a renal cell carcinoma.

MATERIALS AND METHODS

Using linked SEER (Surveillance, Epidemiology and End Results)-Medicare data, we identified patients older than 66 years who underwent partial nephrectomy or radical nephrectomy for T1a (4 cm or smaller) renal cell carcinoma from 1995 to 2007. The effects of procedure type on overall mortality by age were assessed using time dependent Cox proportional hazards models adjusted by propensity score based weighting.

RESULTS

A total of 5,496 patients (mean age 74.2 ± 5.6 years, 55.9% male) who underwent partial nephrectomy (1,665; 30.3%) or radical nephrectomy (3,831; 69.7%) for 4 cm or smaller renal cell carcinoma (mean tumor size 2.8 ± 0.9 cm) were identified. After adjustment, a statistically significant survival benefit for partial nephrectomy compared to radical nephrectomy was observed at 1 year (age 68, HR 1.6, CI 1.2-2.3; age 75, HR 1.5, CI 1.1-1.9; age 85, HR 1.7, CI 1.1-2.5) and 3 years (age 68, HR 1.4, CI 1.03-2.0; age 75, HR 1.3, CI 1.1-1.6; age 85, HR 1.5, CI 1.02-2.3), while these trends became insignificant in patients younger than 68 and older than 85 years. However, the survival benefit decreased with time, and little significant benefit with partial nephrectomy was observed at 5 and 10 years after surgery regardless of age (66 years or older).

CONCLUSIONS

Lacking strong evidence regarding a long-term survival benefit, the decision to perform partial nephrectomy in elderly patients should be individualized, and placed in the context of baseline renal function, expected surgical morbidity and competing risks to survival.