No. 069. Overtreatment of Small Renal Masses with Radical Nephrectomy in Victoria – Should We Be Concerned?.
Overtreatment of Small Renal Masses with Radical Nephrectomy in Victoria – Should We Be Concerned?
Anthony D. Ta1,2, Margaret K. Dimech3, Victoria White3, Damien M. Bolton1,2, Michael Coory4, Ian D. Davis1,2, Jeremy Millar5, Graham G. Giles2,3 and the IMPROVE Study Team3
1Austin Health, 2The University of Melbourne, 3The Cancer Council of Victoria, 4Murdoch Children’s Research Institute, 5The Alfred Hospital
Partial nephrectomy (PN) for small renal tumours provides similar oncological control as radical nephrectomy (RN) with reduced risk of subsequent chronic kidney disease.1,2 Data assessing contemporary surgical management of early stage renal cell carcinoma (RCC) in Australia are lacking. To address this issue, we evaluated the patterns of surgical management of localised RCC in Victoria using a contemporary whole-of-population cohort.
A total 577 cases were eligible for inclusion; data were available for 499 patients for analysis. Median age at diagnosis was 63 years (range 14-97). Most patients were male (65.3%) and resided in metropolitan areas (72.9%). 302 (60.5%) patients presented with an incidental finding of a renal mass. 17% of patients had radiological evidence of metastatic disease at presentation. There were no significant differences between metropolitan and regional/rural patients with regards to presentation or co-morbidities.
Overall, 82.9% of cases underwent surgical treatment. While surgery was not related to residential location, it was inversely associated with age (p<.001) and co-morbidities (p<.001). Surgical treatment was generally RN (336, 81.2%), with a laparoscopic approach accounting for 254 (61.3%) cases. 171 of 186 pT1a tumours were managed with surgery; 104 (60.8%) patients received RN, of which 81.7% were performed laparoscopically. Radiofrequency ablation was used in 4 cases.
For pT1a/pT1b RCC, PN was less commonly performed amongst regional patients compared to those from metropolitan areas (16.2% vs 31.3%). This difference remained significant in multivariate analysis (OR 0.41, 95% CI 0.19-0.89). Surgical treatment of pT1a lesions is shown in Table 1. Regional patients with pT1a RCC were less likely to receive PN (OR 0.46, 95% CI 0.26-1.03) and more likely to receive open RN (OR=3.00, 95%CI 1.09-8.25).
However, when comparing treatment locations, no difference in likelihood of receiving PN for pT1a tumours was detected between patients treated in regional compared to metropolitan hospitals. Patients treated in regional hospitals were significantly less likely to undergo laparoscopic surgery (OR 0.07, 95% CI 0.02-0.25), but this finding is limited by small numbers of pT1a tumours treated in regional hospitals (only 10.8% of all pT1a) . Furthermore, we have not accounted for patient preferences or treatment of regional patients in metropolitan areas, such as Geelong.
The study was approved by the ethics committee of The Cancer Council Victoria. All cases of RCC diagnosed in Victoria in 2009 and registered with the Victorian Cancer Registry (VCR) were identified. Victorian residents treated in Victoria were eligible for inclusion. Retrospective review of medical records and pathology reports was performed with assistance of public hospitals and private specialist clinics.
Data extracted included mode of presentation, clinical (cT) and pathological (pT) disease stage and first-line treatment. Patient co-morbidity was assessed using the ACE-27 co-morbidity risk assessment tool. The 2009 AJCC TNM staging system was used to calculate pT stage; cT stage obtained from imaging was used where pT stage was unavailable. Patient residency and treatment locations (metropolitan vs regional) were determined based on the Department of Human Services Integrated Cancer Services regions. Geelong was classified as metropolitan.
Multivariate logistic regression was used to detect regional differences in treatment procedures after adjusting for age, sex, patient co-morbidity and tumour stage where appropriate. Metropolitan location was the reference category in these analyses.
Table 1. Surgical Management of T1a RCC by Patient Residential Location
OR = Odds ratio
† Analyses adjusted for age, sex, ACE-27 comorbidity index
*Excludes pT1a managed non-operatively
Contemporary whole-of-population data shows that most patients with diagnosed with T1a stage RCC in Victoria undergo extirpative RN. The popularity of laparoscopic RN may contribute to overtreatment of this sub-group of patients, predisposing them to increased risk of chronic kidney disease and its associated global health problems. Further work is required to assess if regional differences in surgical management persist in a larger population study.
The IMPROVE Study Team: GianlucaSeveri, Miles Prince, Simon Harrison, John Seymour, Ingrid Winship, Ian Roos, Anne Kay, Michael Jefford, David Hill, Melissa Southey
The Victorian Cancer Agency
A/Prof Ian D Davis is an NHMRC practitioner fellow
Poster presentation sponsor