Surgical management of stage T1 renal tumours at Canadian academic centres

Percutaneous Microwave Ablation Versus Robot-Assisted Partial Nephrectomy for Stage I Renal Cell Carcinoma: A Propensity-Matched Cohort Study Focusing Upon Long-Term Follow-Up of Oncologic Outcomes

PURPOSE

To retrospectively compare long-term oncologic outcomes of percutaneous computed tomography-guided microwave ablation (MWA) and robot-assisted partial nephrectomy (RAPN) for the treatment of stage 1 (T1a and T1b) renal cell carcinoma (RCC) patients.

MATERIALS AND METHODS

Institutional database research identified all T1 RCC patients who underwent either MWA or RAPN. Models were adjusted with propensity score matching. Kaplan-Meier log-rank test analyses and Cox proportional hazard regression models were used to compare the oncologic outcomes. Patient and tumor characteristics, technical success as well as oncologic outcomes were evaluated and compared between the 2 groups.

RESULTS

After propensity score matching, a total of 71 patients underwent percutaneous MWA (mean age 70 ± 10 years) and 71 underwent RAPN (mean age 60 ± 9 years). At 8-year follow-up, the estimated survival rates for MWA cohort were 98% (95% confidence interval [CI] 95-100%) for overall survival, 97% (95% CI 93-100%) for recurrence-free survival, and 97% (95% CI 93-100%) for metastasis-free survival. The matched cohort that underwent RAPN exhibited survival rates of 100% (95% CI 100-100%) for overall survival, 98% (95% CI 94-100%) for recurrence-free survival, and 98% (95% CI 94-100%) for metastasis-free survival. After performing log-rank testing, these rates were not significantly different (p values of 0.44, 0.67, and 0.67, respectively).

CONCLUSION

The results of the present study suggest that both MWA and RAPN are equally effective in terms of oncologic outcome for the treatment of T1 RCC.

The impact of robotic surgery access on the management of patients with clinical stage I kidney tumors

INTRODUCTION

Robotic surgery is used in the treatment of kidney tumors. We aimed to determine if robotic access was associated with initial choice of management for patients with a clinical stage I kidney mass.

METHODS

Patients with a clinical stage I kidney mass were identified from the Canadian Kidney Cancer information system (CKCis) cohort. Sites were classified by year and access to robotic surgery. Associations between robotic access and initial management were determined using logistic regression. Univariable and multivariable analyses were performed, adjusting for tumor size and stage, and presented as relative risks (RR ) or adjusted RR (aRR) and 95% confidence intervals (CI).

RESULTS

Overall, 4160 patients were included. Among patients treated with surgery, the proportion of partial nephrectomy compared to radical nephrectomy was significantly higher in robotic sites (77.3% for robotic sites vs. 65.9% for non-robotic sites; RR 1.17, 95% CI 1.12-1.23, p<0.0001; aRR 1.12, 95% CI 1.08-1.17, p<0.0001). Patients receiving partial nephrectomy at sites with robotic access were more likely to receive a minimally invasive approach compared to patients at non-robotic sites (61.4% vs. 50.9%, RR 1.21, 95% CI 1.12-1.30; aRR 1.16, 95% CI 1.08-1.25, p<0.0001). The proportion of patients managed by active surveillance was not significantly different between robotic (405, 16.9%) and non-robotic (258, 14.7%) sites (RR 1.15, 95% CI 0.99-1.32; aRR 0.97, 95% CI 0.84-1.12).

CONCLUSIONS

Access to robotic kidney surgery was associated with increased use of partial nephrectomy and minimally invasive partial nephrectomy. Use of active surveillance was similar at robotic and non-robotic institutions. Limitations of this study include lack of data on perioperative complications and cancer recurrence.

Derivation and validation of text search algorithms for renal and adrenal lesion identification in radiology text reports

INTRODUCTION

Most cohort studies are limited by sampling and accrual bias. The capability to detect specific lesions identified in radiological text reports could eliminate these biases and benefit patient care, clinical research, and trial recruitment. This study derived and internally validated text search algorithms to identify four common urological lesions (solid renal masses, complex renal cysts, adrenal masses, and simple renal cysts) using radiology text reports.

METHODS

A simple random sample of 10 000 abdominal ultrasound (US) and computed tomography (CT) reports was drawn from our hospital's data warehouse. Reports were manually reviewed to determine the true status of the four lesions. Using commonly available software, we created logistic regression models having as predictors the status of a priori selected text terms in the report. We used bootstrap sampling with 95^th percentile thresholds to select variables for the final models, which were modified into point systems. A second independent, random sample of 2855 reports, stratified by the number of points for each abnormality, was reviewed in a blinded fashion to measure the accuracy of each lesion's point system.

RESULTS

The prevalence of solid renal mass, complex renal cyst, adrenal mass, and simple renal cyst, was 2.0%, 1.7%, 3.2%, and 20.0%, respectively. Each model contained between one and five text terms with c-statistics ranging between 0.66 and 0.90. In the independent validation, the scoring systems accurately predicted the probability that a text report cited the four lesions.

CONCLUSIONS

Textual radiology reports can be analyzed using common statistical software to accurately determine the probability that important abnormalities of the kidneys or adrenal glands exist. These methods can be used for case identification or epidemiological studies.

Transplanting kidneys from donors with small renal masses - a strategy to expand the donor pool

INTRODUCTION

Renal transplantation is the optimal treatment for end-stage renal disease, but organ demand continues to outstrip supply. The transplantation of kidneys from donors with small renal masses (SRMs) represents a potential avenue to expand the donor pool. We reviewed all published cases of transplants from donors with SRMs and we present followup data, best practices, and outline an actionable series of steps to guide the implementation of such transplants at individual centers.

METHODS

A detailed literature search of the MEDLINE/PubMed and SCOPUS databases was performed. Thirty unique data sets met inclusion criteria and described the transplantation of tumor-ectomized kidneys; nine data sets described the transplantation of contralateral kidneys from donors with SRMs.

RESULTS

A total of 147 tumorectomized kidneys have been transplanted. Pathology revealed 120 to be renal cell carcinomas (RCCs), of which 116 were stage T1a (0.3-4 cm). The mean followup time was 44.2 months (1-200). A single suspected tumor recurrence occurred in one patient nine years post-transplantation and it was managed with active surveillance. Twenty-seven kidneys have been transplanted from deceased donors with contralateral renal masses. Pathology revealed 25 to be RCCs, of which 19 were confirmed to be stage T1 (<7 cm). The mean followup time was 46.7 months (0.5-155). One recipient developed an RCC and underwent curative allograft nephrectomy.

CONCLUSIONS

Careful use of kidneys from donors with SRMs is feasible and safe, with an overall recurrence rate of less than 1.5%. The use of such kidneys could help alleviate the organ shortage crisis.

Renal hypothermia during partial nephrectomy for patients with renal tumours: a randomised controlled clinical trial protocol

INTRODUCTION

Partial nephrectomy is a standard of care for non-metastatic renal tumours when technically feasible. Despite the increased use of partial nephrectomy, intraoperative techniques that lead to optimal renal function after surgery have not been rigorously studied. Clamping of the renal hilum to prevent bleeding during resection causes temporary renal ischaemia. The internal temperature of the kidney may be lowered after the renal hilum is clamped (renal hypothermia) in an attempt to mitigate the effects of ischaemia. Our objective is to determine if renal hypothermia during open partial nephrectomy results in improved postoperative renal function at 12 months following surgery as compared with warm ischaemia (no renal hypothermia).

METHODS AND ANALYSES

This is a multicentre, randomised, single-blinded controlled trial comparing renal hypothermia versus no hypothermia during open partial nephrectomy. Due to the nature of the intervention, complete blinding of the surgical team is not possible; however, surgeons will be blinded until the time of hilar clamping. Glomerular filtration will be based on plasma clearance of a radionucleotide, and differential renal function will be based on renal scintigraphy. The primary outcome is overall renal function at 12 months measured by the glomerular filtration rate (GFR). Secondary outcomes include change in GFR, GFR of the affected kidney, change in GFR of the affected kidney, serum creatinine, haemoglobin, spot urine albumin to creatinine ratio, quality of life and postoperative complications. Data will be collected at baseline, immediately postoperatively and at 3, 6, 9 and 12 months postoperatively.

ETHICS AND DISSEMINATION

Ethics approval was obtained for all participating study sites. Results of the trial will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT01529658; Pre-results.

Follow-up imaging after nephrectomy for cancer in Canada: urologists' compliance with guidelines. An observational study

BACKGROUND

Surgical tumour removal remains the preferred treatment for most patients with renal cell carcinoma, and many medical associations have proposed guidelines for the optimal surveillance of patients following surgery. This study evaluated the adherence of Canadian urologists to the follow-up guidelines proposed by the Canadian Urological Association (CUA) in 2009.

METHODS

The study cohort was identified from the Canadian Kidney Cancer Information System, a prospectively populated database from 15 academic institutions in 6 Canadian provinces: British Colombia, Alberta, Manitoba, Ontario, Quebec and Nova Scotia. A total of 1982 patients who underwent radical or partial nephrectomy for stage pT1-3N0M0 renal cancer between January 2011 and June 2016 were included in the cohort. Numbers of abdominal and chest imaging tests performed during the follow-up period were captured and compared with the 2009 CUA guidelines. The level of compliance was measured by means of weighted κ and Pearson correlation statistics. Multivariate logistic regression was used to evaluate factors associated with noncompliance (under- or overtesting) in the postoperative surveillance period.

RESULTS

Of the 1982 patients, 1380 had stage pT1 disease, 164 had stage pT2 disease, and 438 had stage pT3 disease. There was incongruent adherence to the CUA surveillance guidelines, with a ratio of observed to recommended tests of 0.71 and 2.27 for chest and abdominal imaging, respectively. Overall, moderate correlation between observed and recommended tests was observed, with the highest value found for abdominal imaging in the pT3 group (κ = 0.59 [95% confidence interval 0.52-0.66]). Patients who underwent radical nephrectomy and those who presented with a higher stage of the disease were less likely to receive fewer chest imaging tests than recommended, and those with stage pT2 disease, those with stage pT3 disease, those with conventional clear cell renal cell carcinoma and those with a low-risk histologic type had an increased risk of undertesting.

INTERPRETATION

In the 6 Canadian provinces, there are large differences between guidelines and clinical practice in imaging surveillance after nephrectomy for renal cell carcinoma. Better adherence to clinical guidelines could improve optimization of health care services.