Evaluation of Tumor Pseudocapsule Status and its Prognostic Significance in Renal Cell Carcinoma.

PURPOSE: We determined whether tumor pseudocapsule status, including the extent of invasion by cancer and lack of a pseudocapsule, has prognostic value in renal cell carcinoma.

MATERIALS AND METHODS: We retrospectively reviewed the records of 1,577 patients with different stages of renal cell carcinoma who underwent nephrectomy at our institution, of whom 1,307 (82.9%) were eligible for analysis. Presented pseudocapsules were classified as grade 0-completely intact, grade 1-merely involved and grade 2-penetrated. We studied overall and progression-free survival using the Kaplan-Meier method and a Cox regression model.

RESULTS: Of the 1,307 patients 1,244 (95.2%) presented with a pseudocapsule, including 350 (28.1%), 643 (51.7%) and 251 (20.2%) with a grade 0, 1 and 2 pseudocapsule invasion extent, respectively. Kaplan-Meier curves revealed great losses in overall and progression-free survival for an increased extent of invasion and pseudocapsule absence. On multivariate analyses we identified significant overall and progression-free survival harms for grade 2 pseudocapsules (HR 2.12 and 2.66, each p <0.0001) and lack of a pseudocapsule (HR 1.95, p = 0.0248 and HR 2.54, p = 0.0007, respectively) compared to grade 0 pseudocapsules. A change in statistical risk from grade 1 to 0 was only detected for progression-free survival. The prognostic value of pseudocapsule status was shown by a higher HR on multivariable analyses in individuals with localized renal cell carcinoma.

CONCLUSIONS: Our findings suggest that pseudocapsule status has good prognostic implications in renal cell carcinoma. Lack of a pseudocapsule certainly had a remarkably adverse impact on the patient outcome. Accessibility in use and cost makes pseudocapsule status a potential cost-effective parameter in clinical practice.