STOCKHOLM, SWEDEN (UroToday.com) - This multi-center study was presented by Dr. J. R. Bhatt from the University of Toronto. The objective of the study was to evaluate the uptake of renal tumor biopsy (RTB) for clinical T1 tumors, across Canadian centers, using the centralized database, Canadian Kidney Cancer Information System (CKCis). They examined 2 927 patients’ demographics, biopsy diagnostic rates, histological subtype, and grade, and then determined the concordance rates with final surgical pathology. A total of 616 RTBs (552 patients) between 1994 and 2013 were obtained.
They reported an exponential increase in the uptake of renal biopsies across Canada, especially over the past few years. Ninety percent had one biopsy, while 10% of patients had 2 or more. Of 470 patients with a recorded clinical T-stage, 259 (55%) were cT1a tumors, with 45% biopsies performed on > cT1b lesions. For the cT1a sub-group of 259 patients, a diagnosis was available in 236, or 91%. Of these, a malignant diagnosis was made in 80.5%, while 19.6% were benign. Histological subtype was available in 88% of biopsies; 190 malignant (117 conventional, 44 papillary and 29 chromophobe) and 18 benign (2 angiomyolipoma and 16 oncocytoma). Grade was recorded for 67% of malignant cases. A total 116 tumors were excised and of all lesions recorded with a final surgical pathology; there was a 100% malignancy concordance rate. Grade and histology concordance were lower at the 65% and 75-85% range, respectively.
This study confirms that even though the concordance rate for obtaining grade and histology has room to improve, the overall diagnostic and malignancy concordance rate of RTB is excellent and should be utilized more often, especially for masses which are under consideration for active surveillance.
Presented by J. R. Bhatt at the 29th Annual European Association of Urology (EAU) Congress - April 11 - 15, 2014 - Stockholmsmässan - Stockholm, Sweden.
University of Toronto Health Network, Princess Margaret Hospital, Toronto Canada
Written by Reza Mehrazin, MD, medical writer for UroToday.com