Renal tumor biopsies (RTB) have been proposed as a means to diminish overtreatment of small renal masses. A potential concern of RTB is tumor seeding along the biopsy tract leading to worse clinical outcomes.
To evaluate whether RTB was associated with greater upstaging to pT3a compared to patients without a biopsy and to determine if pathologic upstaging affects the risk of recurrence.
The Canadian Kidney Cancer information system was used to identify patients who underwent radical or partial nephrectomy for malignant renal tumors ≤ 4cm (cT1a) between January 1, 2011 and July 2, 2019.
RTB prior to nephrectomy or nephrectomy without biopsy.
Upstaging to pT3a and cancer recurrence were compared between subjects that had a RTB compared to those who did not. A multivariable analysis was used to evaluate factors associated with disease upstaging and recurrence.
The cohort consisted of 1993 cT1a patients, followed for a median of 17.5 months. Of these patients, 502 (25%) had a preoperative RTB. There was no difference in the proportion with tumor upstaging to pT3a between patients that had RTB compared to those who did not (7.2% vs. 6.3%; P = 0.5). On multivariable analysis, RTB was not associated with pathological upstaging (Odds Ratio 0.90; 95% Confidence Interval 0.61-1.34) or recurrence (Odds Ratio 1.04; 95% Confidence Interval 0.57-1.89). The main limitation is that the study is underpowered to detect small differences between groups.
In this large, multi-institution cohort, RTB was not associated with increased risk of tumor upstaging or recurrence. Hence, tumor tract seeding, although possible, should not be a clinical deterrent to using RTBs as a means of personalizing renal masses management and diminishing overtreatment.
Recent evidence suggests that tumor seeding following RTB may be more common than initially perceived. Our results have demonstrated that RTB was not associated with an increased risk of tumor upstaging or disease recurrence.
Urologic oncology. 2020 Jul 18 [Epub ahead of print]
Charles Asselin, Antonio Finelli, Rodney H Breau, Ranjeeta Mallick, Anil Kapoor, Ricardo A Rendon, Simon Tanguay, Frédéric Pouliot, Adrian Fairey, Luke T Lavallée, Franck Bladou, Jun Kawakami, Alan I So, Patrick O Richard
Urology, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada., Urology, University Health Network, Toronto, ON, Canada., Urology, Ottawa Hospital, Ottawa, ON, Canada; Urology, Ottawa Hospital Research Institute, Ottawa, ON, Canada., Urology, Ottawa Hospital Research Institute, Ottawa, ON, Canada., Urology, St. Joseph Healthcare, Hamilton, ON, Canada; Urology, Juravinski Hospital, Hamilton, ON, Canada., Urology, Capital Health - QEII, Halifax, NS, Canada., Urology, McGill University Health Centre, Montréal, QC, Canada., Urology, Centre Hospitalier Universitaire de Québec, Québec City, QC, Canada., Urology, Alta Health Services, Edmonton, AB, Canada., Urology, Jewish General Hospital, Montréal, QC, Canada., Urology, Alberta Health Service, Calgary, AB, Canada., Urology, British Columbia Cancer Care, Vancouver, BC, Canada., Urology, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada. Electronic address: .