Size and Volumetric Growth Kinetics of Renal Masses in Patients With Renal Cell Carcinoma

Abstract

Objective: To examine radiological growth patterns as an indicator of renal tumor aggressiveness, we studied about the growth kinetics of small renal mass (SRM, ≤4 cm) and possible associated factors for high Fuhrman nuclear grade (≥3).

Materials and methods: From January 1999 to May 2013, 112 cases (111 patients) diagnosed as renal cell carcinoma after surgical treatment were reviewed retrospectively. Patients who had at least two preoperative contrast-enhanced computed tomography scans more than 6 months apart were included.

Results: The mean age was 59 years and mean computed tomography follow-up duration was 20 months. Median tumor size and tumor volume at diagnosis were 1.45 cm and 1.80 cm(3), respectively. Median linear growth rate (LGR) was 0.28 cm/year. Median volumetric growth rate was 0.75 cm(3)/year and median volume doubling time was 1.41 years. Tumor growth rate was not different to histologic type (P = .271). High LGR was a significant factor associated with high Fuhrman grade in multivariate analysis (odds ratio 3.877, 95% confidence interval 1.715-8.765). Volumetric growth rate (P <.001) and volume doubling time (P = .004) were positive correlation with initial mass size, but not LGR (P = .764).

Conclusion: In our growth kinetics study, generally small renal mass grew slowly. High LGR could be a risk factor for high-grade tumor (Fuhrman grade ≥3).