Evaluation of Growth Rates for Small Renal Masses in Elderly Patients Undergoing Active Surveillance.

BACKGROUND

As the adoption of active surveillance (AS) for small renal masses (SRMs) grows, the number of elderly patients enrolled for a prolonged period of time will increase. However, our understanding of comparative growth rates (GRs) in aging patients with SRMs remains poor.

OBJECTIVE

To examine whether particular age cutoffs are associated with an increased GR for patients undergoing AS for SRMs.

DESIGN SETTING AND PARTICIPANTS

We identified all patients with SRMs enrolled in the multi-institutional, prospective Delayed Intervention and Surveillance for Small Renal Masses (DISSRM) registry since 2009 who elected for AS.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Two definitions of GR were examined: GR from the initial image (GR) and GR from the prior image (GR). Image measurements were dichotomized based on patient age at the time of imaging. Multiple age cutoffs were examined: 65, 70, 75, and 80 yr. Mixed-effect linear regression examined the associations between age and GR, with controlling to account for multiple measurements from the same individual.

RESULTS AND LIMITATIONS

We examined 2542 measurements from 571 patients. The median age at enrollment was 70.9 yr (interquartile range [IQR] 63.2-77.4) with a median tumor diameter of 1.8 cm (IQR 1.4-2.5). As a continuous variable, age was not associated with GR (-0.0001 cm/yr, 95% confidence interval [CI] -0.007 to 0.007,  = 0.97) or GR (0.008 cm/yr, 95% CI -0.004 to 0.020,  = 0.17) after adjustment. The only age thresholds associated with an increased GR were 65 yr for GR and 70 yr for GR. Limitations include the one-dimensional nature of the measurements used.

CONCLUSIONS

Increased age for patients on AS for SRMs is not associated with increased GRs.

PATIENT SUMMARY

We examined whether patients undergoing active surveillance (AS) exhibited accelerated growth of their small renal masses (SRMs) after a certain age. No demonstrable change was seen, suggesting that AS is a safe and durable management option for aging patients with SRMs.