Department of Urology, University of California, San Francisco, San Francisco, CA 94143, USA.
BJU Int. 2012 Sep;110(6):794-7. doi: 10.1111/j.1464-410X.2012.10944.x. Epub 2012 Mar 9.
What's known on the subject? and What does the study add? It is well documented that biopsy of small renal masses is inaccurate and tends to under-estimate tumour grade compared with surgical specimens. To our knowledge there has not been a study showing grading discrepancy between biopsy and surgical excision in a large population-based cohort.
To determine whether differences exist in tumour grade between patients who undergo partial nephrectomy (PN) and those who undergo ablation for renal tumours.
Data was obtained using the Surveillance, Epidemiology and End Results database. Patients with solitary renal tumours of <4 cm treated with ablation or PN and with renal cell carcinoma (RCC) histopathology were identified. Tissue diagnosis in the ablation specimens was obtained from biopsy reports, whereas tissue from PN specimens was determined from surgical pathology. Variables analysed included: year of diagnosis, age, sex, race/ethnicity, marital status, population density, education, poverty level, and tumour size. Stacked bar graphs were created to compare the distributions of grade and histology between the groups. Multinomial logistic regression was used to determine factors independently associated with grade.
In all, 7704 (87.4%) patients underwent PN and 1114 (12.6%) underwent either radiofrequency ablation or cryoablation. The PN patients were younger at diagnosis (59 vs 68 years, P < 0.001), more likely to be married (70% vs 64%, P < 0.001), and had smaller tumours (2.4 vs 2.6 cm, P < 0.001). There were no differences in the distribution of histology between the PN and ablation groups. Tumour grade was significantly lower in tumours treated with ablation. Compared with grade 1 disease, those undergoing ablation were 30% less likely to have grade 2 (P < 0.001), 30% less likely to have grade 3 (P < 0.001), and 92% less likely to have grade 4 disease (P < 0.01) than those having PN.
There is a strong association between grade and treatment type in patients with small renal masses after controlling for baseline characteristics. As grade is determined by different methods, we think that this shows systematic under-grading in biopsy of small renal masses.
确定接受部分肾切除术（PN）和消融治疗的肾肿瘤患者之间肿瘤分级是否存在差异。
使用监测、流行病学和最终结果数据库获得数据。确定了接受消融或 PN 治疗且具有肾细胞癌（RCC）组织病理学的<4cm 单发肾肿瘤患者。消融标本的组织诊断来自活检报告，而 PN 标本的组织来自手术病理。分析的变量包括：诊断年份、年龄、性别、种族/民族、婚姻状况、人口密度、教育程度、贫困水平和肿瘤大小。创建堆叠条形图比较两组之间的分级和组织学分布。使用多项逻辑回归确定与分级独立相关的因素。
共有 7704 例（87.4%）患者接受 PN，1114 例（12.6%）患者接受射频消融或冷冻消融。PN 患者的诊断年龄更小（59 岁 vs 68 岁，P < 0.001），更有可能已婚（70% vs 64%，P < 0.001），且肿瘤更小（2.4cm vs 2.6cm，P < 0.001）。PN 和消融组之间的组织学分布没有差异。消融治疗的肿瘤分级明显较低。与 1 级疾病相比，接受消融治疗的患者 2 级疾病的可能性降低 30%（P < 0.001），3 级疾病的可能性降低 30%（P < 0.001），4 级疾病的可能性降低 92%（P < 0.01）。
在控制基线特征后，小肾肿瘤患者的分级与治疗类型之间存在很强的关联。由于分级是通过不同的方法确定的，我们认为这表明在小肾肿瘤的活检中存在系统的低估分级。
