Prevalence and impact on survival of positive surgical margins in partial nephrectomy for renal cell carcinoma: a population‐based study

Abstract

What's known on the subject? and What does the study add?• The increased detection of small renal masses (SRMs) with diagnostic imaging has highlighted the importance of preserving renal function, with many patients with SRMs being managed with nephron-sparing procedures. The significance of positive surgical margins (PSMs) is debatable and various studies have looked at the risk factors for PSMs and recurrence. It has been suggested that tumour size may be a risk factor and the centrality of the tumour has been found to be an increased risk factor. The indication and location of the tumour has been found to be an independent predictive factor for recurrence.• Various studies have assessed the outcome of patients with PSMs with short-to intermediate-term follow-up. Our study has an intermediate-term median follow-up of 7.9 years, and found no significant difference in 5-year disease-specific and overall survival rates between patients with PSMs and negative surgical margins. We also found that tumour size was not significant, but pathological stage and fat invasion were found to be significant. These risk factors have not been published in previous studies. Objectives• To determine the prevalence of positive surgical margins (PSMs) on a population level.• To identify the predictors of PSMs and assess their impact on survival. Patients and Methods• Using the Ontario Cancer Registry, we reviewed pathology reports on 664 patients after partial nephrectomy for renal cell carcinoma between 1995 and 2004.• Demographic information and pathological characteristics were obtained and multivariable logistic regression analysis was performed to determine the predictors of PSMs.• Kaplan-Meier analysis was used to examine disease-specific (DSS) and overall survival (OS) by margin status. A multivariable Cox proportional hazards model was used to determine the independent association between PSMs and survival. Results• The mean patient age was 57.7 years and 61.6% were men. Tumour size was <2.0 cm in 25%, 2.0-3.9 cm in 59%, 4.0-6.9 cm in 13%, and Ն7.0 cm in 3% of patients.• Seventy-one patients (10.7%) had PSMs on final pathology. Only stage (P = 0.02) and fat invasion (P = 0.04) were significantly associated with PSMs.• At a median follow-up of 7.9 years, the unadjusted 5-year DSS and OS rates were 91.8 and 88.3%, respectively. • Survival rates did not differ by surgical margin status, with 90.9 and 84.4% 5-year DSS and OS rates for patients with PSMs compared with 91.9 and 88.6% for those with a negative surgical margin (P = 0.58, log rank test).• Using a Cox proportional hazards model, surgical margin status was not associated with time to all-cause death (P = 0.67). Conclusion• Our population-level data suggest that, although PSMs are fairly prevalent, they appear to have little to no impact on 5-year survival rates.Keywords nephron-sparing surgery, positive surgical margin, partial nephrectomy, renal cell carcinoma E300 © 2013 BJU International | 111, E300-E305 |

A Prospective, Multicenter Evaluation of Predictive Factors for Positive Surgical Margins After Nephron-Sparing Surgery for Renal Cell Carcinoma: The RECORd1 Italian Project

“…31,32 In a recent report from the Ontario Cancer Registry that evaluated 788 open and laparoscopic PNs, Ani et al found significant correlations between increasing tumor size and margin status, with a 4-fold higher risk of PSM in pT1b tumors (P ¼ .002). 9 In our study the mean tumor dimension and the clinical and pathological stage failed to correlate with PSM status. This finding corroborates the oncological safety of NSS even in cT1b renal tumors, regardless of the surgical approach and technique adopted.…”

“…Ani et al found that age was not independently associated with the higher risk of PSMs at multivariable analysis (OR, 0.99; P ¼ .3). 9 Similarly, Yossepowitch and coworkers did not find any correlation between age and SM status at univariable (OR, 1; P ¼ .77) and multivariable (OR, 1; P ¼ .81) analysis. 11 Despite the previous, historical recommendations to remove at least 1 cm of normal-appearing renal parenchyma around the tumor to ensure negative margins, 25 the current indications for NSS have progressively changed: indeed, according to the recognized oncological safety of NSS even for T1b RCC, 3,26 and to the need for preservation of as much functioning healthy parenchyma as possible to minimize the loss of renal function, 27 NSS has moved from maximal parenchymal resection to minimal tissue removal.…”

“…10 Our series report an overall incidence of PSMs of 4.9%, which is comparable to the results of other NSS series, regardless of the surgical approach (open vs. minimally invasive). 9 To our knowledge, this is one of the largest, multi-institutional prospective studies to evaluate the predictors of PSMs and, to our knowledge, it is the first that included open and minimally invasive NSS in the analyses. …”

“…7 In all cases, NSS might result in incomplete cancer removal, thus causing PSMs, which might need additional follow-up and can lead to a potentially increased risk of local recurrence and disease progression. [8][9][10] In the absence of randomized trials providing strong clinical evidence, several factors have been advocated as predictors of PSMs after NSS, such as tumor size, 11 pathological stage, 9 Fuhrman grade, 12 indication for NSS (elective vs. imperative), 11 and surgical volume. 13 Conversely, the surgical approach (open vs. minimally invasive), and surgical technique (standard PN vs.…”

Clinical outcomes following laparoscopic management of pT3 renal masses: A large, multi-institutional cohort

“…However, the risk of local recurrence in those with a positive margin remains controversial. 26,27 Much of the data on positive margins after partial nephrectomy indicate that these margins do not predict worse outcomes, 28 although most of this data were collected in patients with lower risk tumours. It is possible that positive margins are biologically more relevant in pT3 tumours.…”