Growth Pattern of Clear Cell Renal Cell Carcinoma in Patients with Delayed Surgical Intervention: Fast Growth Rate Correlates with High Grade and May Result in Poor Prognosis.

Lei Zhang,Wenshi Yin,Da Ren,Weimin Ci,Zhongyuan Zhang,Liqun Zhou,Yu Fan,Lin Yao,Xuesong Li,Qun He,Zhisong He,Dong Fang

doi:10.1155/2015/598134

Abstract

Objectives. Previous studies revealed an unclear correlation between the growth rate of renal cell carcinoma (RCC) and tumor grade and did not focus on certain histological subtype. This report investigated the correlation between the growth rate and tumor grade in clear cell RCC (ccRCC). Methods. We reviewed 60 patients with 61 ccRCC confirmed by delayed surgeries after at least 12 months of active surveillance. The linear growth rate (LGR), volumetric growth rate (VGR), and volume doubling time (VDT) were calculated, and their correlations with clinicopathologic characteristics were analyzed. Results. The mean LGR, VGR, and VDT were 0.86 (range 0–4.74) cm/year, 20.96 (range 0.31–211.93) cm3/year, and 667 (range 33–3321) days, respectively. ccRCCs with high grade had greater LGR (P < 0.001) and VGR (P = 0.001) and lower VDT (P = 0.017) than ccRCCs with low grade. Grade (OR = 5.185, P = 0.004) was the only independent risk factor of LGR >0.5 cm/year, and grade (OR = 3.006, P = 0.046) and initial size (OR = 0.392, P = 0.004) were independent risk factors of VDT <1 year. Five patients developed metastasis after surgery with LGR >0.5 cm/yr altogether; of them, four had cancer-related death by the last follow-up. Conclusions. Fast growth rate of ccRCC is significantly correlated with high tumor grade and may result in poor prognosis, especially for those with LGR >0.5 cm/yr.

Highlights

Due to high surgical comorbidity or short life expectancy for certain patients, active surveillance (AS) for renal tumors is being applied selectively by urologists in clinical practice
A total of patients with clear cell RCC (ccRCC) treated by delayed treatment after at least 12 months of AS were identified for analysis
A pooled analysis demonstrated that renal tumors that progressed during AS were predominantly ccRCC [1]

Summary

Introduction

Due to high surgical comorbidity or short life expectancy for certain patients, active surveillance (AS) for renal tumors is being applied selectively by urologists in clinical practice. The risk of metastasis progression during AS is only approximately 2% [1], there is no effective systemic therapy for RCC. Growth rate of renal tumors is believed to be the main trigger for intervention during AS. There is no evidence supporting that the growth rate of RCC during AS is related to its prognosis so far. Because of the limitation of small sample size, the lack of pathological diagnosis, the generally favorable prognosis of RCC, and the follow-up not long enough until the cancerrelated death occurred, it is hard to directly figure out whether fast growth rate under AS is related to poor prognosis of RCC

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Conclusion