RENAL nephrometry score is a predictive factor for the annual growth rate of renal mass.

OBJECTIVE

To evaluate the association between the RENAL nephrometry score and annual growth rates of renal masses presumed to be renal cell carcinoma.

METHODS

The current study included 47 renal tumors followed up for at least 12 months, of which 26 tumors were found to be pathologically proven renal cell carcinomas. Annual tumor growth rates were calculated from changes in the maximal diameter on computed tomography, and RENAL nephrometry scores were recorded on initial imaging by two senior urologists. The associations between clinical characteristics including the RENAL nephrometry score and annual growth rates were analyzed using a linear regression model.

RESULTS

The median tumor size at diagnosis was 1.7 cm (range 0.6-5.8). The median nephrometry score at diagnosis was 7 (range 4-10). Overall, the median tumor growth rate was 0.34 cm per year (range -0.19-2.0). Linear regression analysis showed that the annual tumor growth rate was associated with the RENAL nephrometry score (P < 0.0001), but it was independent of the age at diagnosis, sex and initial tumor size. In addition, the correlation between the RENAL nephrometry score and annual growth rate remained significant in the 26 pathologically proven renal cell carcinomas.

CONCLUSIONS

The RENAL nephrometry score is associated with the annual growth rate of renal masses. Our findings further support the association between the RENAL nephrometry score and tumor biology.