Importance of Surgical Margins in the Management of Renal Cell Carcinoma

Summary and Introduction

Summary

Surgical resection remains the standard treatment for clinically localized renal cell carcinoma. Pathological features of the surgical specimen, including the margin status, play an important part in determining the patient’s prognosis. Negative surgical margins have traditionally been sought to maximize the efficacy of treatment. Initial concerns that partial nephrectomy might have high local recurrence rates compared with radical nephrectomy have now been minimized as a result of technological advances and refinements in surgical technique. Current concerns in relation to partial nephrectomy include the width of parenchymal tissue that should be removed to avoid positive surgical margins, effects of positive margins on recurrence-free survival, and the use of frozen-section analysis to determine margin status. Size of the surgical margin in partial nephrectomy does not seem to affect the risk of local tumor recurrence, and not all positive surgical margins lead to recurrent disease. Intraoperative frozen-section analysis is not definitive and its value in guiding the surgical management of renal tumors remains to be defined. Laparoscopic partial nephrectomy is emerging as an attractive approach for selected renal masses. Intraoperative use of ultrasound, cold-scissor parenchymal transection, embolization, and hilar clamping to achieve a bloodless operative field with clear visibility, may minimize the risk of positive margins during partial nephrectomy.

Introduction

There are an estimated 200,000 new diagnoses of renal cell carcinoma (RCC) and over 100,000 deaths from RCC each year in North America, Europe and Australia.^[1] The gold-standard treatment for renal tumors is radical or partial nephrectomy; however, approximately one-third of patients who undergo surgical resection for clinically localized RCC will develop tumor recurrence.^[2] The indications for nephron-sparing surgery—once reserved for patients with solitary kidneys, bilateral renal tumors, or renal insufficiency—have been expanded to allow elective partial nephrectomy for selected patients with a normal contralateral kidney.

The rationale for expanding the indications for nephron-sparing surgery includes an increase in the life expectancy of the general population, along with an increase in incidental diagnoses of RCC in younger patients. These features have led to increased concern about the long-term risks of renal insufficiency or contralateral tumor recurrence in patients who undergo radical nephrectomy. The generally suggested indication for elective partial nephrectomy is a small renal mass, usually less than 4 cm, located peripherally and easily amenable to resection.^[3] However, there are emerging data that partial nephrectomy can be performed in patients with anatomically amenable tumors larger than 4 cm, provided that an adequate surgical margin can be safely obtained.^[4,5] There is concern that patients who undergo partial nephrectomy might subsequently develop ipsilateral renal recurrence, which can be attributed to multifocal renal tumors, de novo development of a second primary tumor, or a positive surgical margin. Furthermore, patients with positive surgical margins at partial nephrectomy have previously been reported to have shorter cancer-specific survival times compared with those with negative margins.^[6] This Review will focus on the importance of surgical margin status after surgical resection and address technical considerations that minimize the risk of positive surgical margins.