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

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.

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.

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.

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.