Clinical outcomes in cats with renal carcinoma undergoing nephrectomy: A retrospective study

Abstract

Renal carcinomas (RC) are uncommonly encountered in feline medicine. Limited information regarding clinical presentation and postoperative outcomes is available. The purpose of this multi‐institutional, retrospective study was to describe the presenting features and clinical outcomes of cats with RC undergoing nephrectomy. Thirty‐six client‐owned cats were included. Medical records from participating institutions were searched to identify cats that had a histopathologic diagnosis of RC and underwent nephrectomy from January 2001 to October 2021. The most common presenting complaints were weight loss (36.1%) and hyporexia (30.6%). Based on preoperative imaging and intraoperative findings, eight cats had suspected metastasis at the time of surgery (22.2%). Twenty‐eight cats survived to discharge (77.8%). Median progression free interval (PFI) could not be determined, as only six cats developed suspected recurrence (16.7%) and seven cats developed suspected metastasis (19.4%). The all‐cause median survival time (MST) was 203 days (95% confidence interval [CI]: 84, 1379 days). When cases that died prior to discharge were excluded, MST increased to 1217 days (95% CI: 127, 1641 days). One‐year, two‐year, and three‐year survival rates were all 40.4%. Neither renal tumour histologic subtype nor the presence of preoperative azotemia, anaemia, erythrocytosis, haematuria, or suspected metastasis at diagnosis were found to influence survival. For cats surviving to discharge, prolonged survival times were possible. Further studies are necessary to elucidate other potential prognostic factors, the utility of postoperative adjuvant treatment, and to identify cats at‐risk of mortality in the perioperative period.

Ultrasonographic Renal Subcapsular Thickening in Cats with Primary and Metastatic Carcinoma

“…Renal ultrasound images were obtained using linear array transducers (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Depending on facilities, either ultrasound machine, ARIETTA 70 (Hitachi ALOKA Medical Corporation, Mitaka, Japan), ARIETTA 65 (FUJIFILM Healthcare Corporation, Tokyo, Japan), or Aplio i800 (Canon Medical Systems, Tustin, CA, USA) was used.…”

“…The most common neoplasia in the feline kidney is infiltrating neoplasia, such as lymphoma, and the primary renal neoplasia is less common [ 7 , 8 , 9 ]. Renal cell carcinoma is the most common primary renal neoplasm in cats, accounting for more than half of primary renal neoplasms in cats [ 8 , 9 , 10 , 11 , 12 ]. Other primary feline renal neoplasms are reported to occur far less frequently.…”

“…The characteristic appearance of renal carcinoma is that of a spherical or ovoid mass situated at one pole of the kidney, with clear demarcation from the remaining renal tissue [ 4 , 5 , 8 , 14 ]. In a previous study, renal masses were identified in 93% of canine renal carcinoma cases [ 17 ] and in 72% of feline cases [ 9 ], either through abdominal ultrasound or computed tomography (CT). A few cases of primary renal neoplasia, including undifferentiated malignant neoplasia and renal anaplastic carcinoma, have been reported to cause hypoechoic subcapsular thickening of the kidney in cats [ 1 ].…”

“…Renal neoplasia is relatively rare in domestic animals, accounting for less than 1.7% and 2.5% of all tumors in dogs and cats, respectively [4][5][6]. The most common neoplasia in the feline kidney is infiltrating neoplasia, such as lymphoma, and the primary renal neoplasia is less common [7][8][9]. Renal cell carcinoma is the most common primary renal neoplasm in cats, accounting for more than half of primary renal neoplasms in cats [8][9][10][11][12].…”

“…Feline renal carcinoma is predominantly reported in middle-aged to older cats, with no apparent sex or breed predisposition [5,7,13,14]. Typically, renal carcinoma manifests as a solitary nodule or mass unilaterally located in either the left or right kidney [4,5,9], although instances of multiple or bilateral renal carcinoma have also been documented [5,15,16]. The characteristic appearance of renal carcinoma is that of a spherical or ovoid mass situated at one pole of the kidney, with clear demarcation from the remaining renal tissue [4,5,8,14].…”