Comparison of Partial Versus Radical Nephrectomy Effect on Other-cause Mortality, Cancer-specific Mortality, and 30-day Mortality in Patients Older Than 75 Years

Background: Historically, partial nephrectomy (PN) showed no benefit on other-cause mortality (OCM) in elderly patients with small renal masses.

Objective: To test the effect of PN versus radical nephrectomy (RN) on OCM, cancer-specific mortality (CSM), as well as 30-d mortality in patients with nonmetastatic T1a renal cell carcinoma (RCC), aged ≥75 yr old.

Design, setting, and participants: Within the Surveillance, Epidemiology and End Results registry (2004-2014), we identified surgically treated patients with nonmetastatic pT1a RCC aged ≥75 yr.

Outcome measurements and statistical analysis: We relied on propensity score (PS) matching to reduce the effect of inherent differences between PN and RN. After PS matching, cumulative incidence, multivariable competing-risks regression (CRR) and logistic regression models were used. LOESS plots graphically depicted the relation between nephrectomy type and OCM after adjustment for all the covariates. Landmark analyses at 6 mo tested for immortal time bias.

Results and limitations: Of all 4541 patients, 41.6% underwent PN. After 1:1 PS matching, 2826 patients remained. In multivariable CRR models, lower OCM rates were recorded in PN patients (hazard ratio [HR]: 0.67, confidence interval [CI]: 0.54-0.84; p<0.001). LOESS plots showed lower OCM rates after PN across all examined ages. Lower CSM rates were also recorded in PN patients (HR: 0.64, CI=0.44-0.92; p=0.02). Landmark analyses rejected the hypothesis of immortal time bias. Finally, PN did not result in different 30-d mortality rates (odds ratio: 1.87; CI: 0.79-4.47; p=0.2) versus RN. Data are retrospective.

Conclusions: PN results in lower OCM in elderly patients with pT1a RCC. Moreover, PN does not contribute to higher CSM or 30-d mortality in patients aged ≥75 yr. In consequence, PN should be given strong consideration, even in elderly patients.

Patient summary: Partial nephrectomy (PN) may protect from renal insufficiency, hypertension, and other unfavorable health outcomes, even in elderly patients. This protective effect results in lower other-cause mortality. Moreover, PN benefits are not undermined by higher cancer-specific mortality or 30-d mortality.