Positive surgical margins in nephron-sparing surgery: risk factors and therapeutic consequences.

Julie Steinestel,Sandra Steffens,Konrad Steinestel,Andres Schrader

doi:10.1186/1477-7819-12-252

Abstract

The increased use of nephron-sparing surgery to treat localized renal cell carcinoma (RCC) lends weight to the question of the value of microscopically positive surgical margins (PSM) in cases with a tumor bed macroscopically free of residual tumor. The aim of this article is to highlight the data available on risk factors for PSM, their clinical relevance, and possible therapeutic consequences. For this purpose, publications on the incidence and relevance of PSM after partial nephrectomy from the last 15 years were examined and evaluated. We summarize that PSM are generally rare, regardless of the surgical procedure, and are seen more often in connection with an imperative indication for nephron-sparing surgery as well as a central tumor location. Most studies describe that PSM lead to a moderate increase in the rate of local relapses, but no study has thus far been able to demonstrate an association with shorter tumor-specific overall survival. Intraoperative frozen section analysis had no positive influence on the risk of definite PSM in most trials. Therefore, we conclude that PSM should definitely be avoided. However, in cases with a macroscopically tumor-free intraoperative resection bed, they should lead to close surveillance of the affected kidney and not to immediate (re)intervention.

Highlights

In recent years, organ-sparing surgery for renal tumors in terms of partial nephrectomy or tumor enucleation has replaced radical nephrectomy as the standard procedure for treating locally confined renal cell carcinoma (RCC) [1,2,3,4,5,6,7,8]
Partial nephrectomy should always aim at complete tumor resection
The width of the normal tissue margin or safety margin around the tumor appears to be of no relevance here [1,23,24], but the increased frequency of partial nephrectomies and tumor enucleations has shown that a limited percentage of surgical specimens have tumor cells in the margin

Summary

Introduction

Organ-sparing surgery for renal tumors in terms of partial nephrectomy or tumor enucleation has replaced radical nephrectomy as the standard procedure for treating locally confined renal cell carcinoma (RCC) [1,2,3,4,5,6,7,8]. Indication Patients with an imperative indication for nephronsparing surgery (such as preexisting renal insufficiency, or a functional or anatomical single kidney) have a higher incidence of larger and more unfavorably located tumors than the total patient population This explains why an imperative indication could be identified as a risk factor for PSM in most studies, at least by univariate analysis. Tumor-specific risk factors According to a study by Kwon et al [29] in 770 patients who underwent open surgery, the PSM rate appears to be unrelated to the histopathological subtype and possibly the differentiation of RCC. An imperative indication for partial renal resection (HR 14.3; 95% CI 1.6 to 21.2) and a central tumor location (HR 1.2; 95% CI 1.06 to 1.8) proved to be independent risk factors for tumor relapse, but not PSM at final pathology [56]

Not significant

Findings

Conclusions