Local tumour bed recurrence after partial nephrectomy tied to solitary kidney, positive margins

Stephen Padilla
12 Feb 2018

Recurrence of local tumour bed in patients who underwent partial nephrectomy correlates with several preoperative factors, such as gender, multiple tumours and a solitary kidney, in addition to intra- and postoperative factors including a positive surgical margin, and higher pathological stage and nephrometry score, according to a recent study.

“The aim of this study was to determine the incidence of narrowly defined local tumour bed recurrence after partial nephrectomy for small renal masses,” researchers said. “We found that patients with local tumour bed recurrence had larger central tumours and a higher proportion of solitary kidney and positive [surgical] margins.”

Compared with patients who had no recurrence (control group), those with local tumour bed recurrence were more likely to have a solitary kidney (27 percent vs 4 percent; p<0.01) and bilateral disease at presentation (23 percent vs 10.4 percent; p=0.02). The presence of positive margins were greater in patients with local tumour bed recurrences than in controls (15.9 percent vs 3 percent; p<0.01). [J Urol 2018;199:393-400]

There was a median time of 23 months (range, 2‒107) between partial nephrectomy and the detection of local tumour bed recurrence. Furthermore, the following factors were associated with local tumour bed recurrence: a solitary kidney at partial nephrectomy, positive margins, multiple tumours, and higher nephrometry score and pathological stage.

“Although reports of local recurrence after partial nephrectomy have been relatively sparse in the current literature, local recurrence in the renal fossa after radical nephrectomy has been well evaluated,” researchers said. [J Urol 2000;164:322; J Urol 2015;194:316; J Urol 2009;181:2044; BJU Int 2006;97:933]

Only a few similar studies have been conducted on local recurrence following partial nephrectomy, and they were all limited by small cohorts and provided broad, variable definitions of local recurrence, they added. [J Endourol 2013;27:1468; Eur Urol 2015;67:252]

“The definitions in the current study may be more likely to have strictly captured true surgical bed recurrence,” researchers said. “Using this narrower definition, we found that 2.1 percent of patients with sporadic small renal masses had local tumour bed recurrence.”

In this study, local tumour bed recurrence was associated with evidence of renal hilum or sinus invasion on preoperative imaging and a higher nephrometry score, suggesting that patients with local recurrence had larger, more central tumours that posed a greater technical challenge, leading to longer operative time and more blood loss.

“In addition, a recent study in patients who underwent radical … or [partial] nephrectomy for cT1 disease showed that tumours in the renal hilum had a higher recurrence rate,” researchers said. [Ann Surg Oncol 2015;22:344]

“While it is already common knowledge for practicing urologists, the results of the current study add to growing evidence that particular care should be taken when treating patients with larger central tumours, especially those with a solitary kidney,” they added.

A retrospective review of charts was conducted involving 2,256 patients with sporadic small renal masses treated with partial nephrectomy between 2000 and 2014. Local tumour bed recurrence was defined as detection of a new enhancing lesion (1) specifically in the surgical defect or (2) in the same region (eg, lower pole) as the partial nephrectomy site.

A total of 44 (1.9 percent) patients with local recurrence were compared to 163 randomly selected patients who underwent partial nephrectomy with no recurrence to identify differences in multiple characteristics.

“Future studies are warranted to explore the relationship between tumour bed recurrence as defined in this study and local recurrence in general, and the implications on prognosis,” researchers said.