Page 44 - CUA Absracts 2022_Fulldraft

2022 CUA Abstracts

MP-3.6 MP-3.7. Table 1. Demographic and clinical characteristics
A prospective, randomized, parallel-controlled pilot trial of and outcomes of active surveillance (AS) and
stereotactic body radiation therapy vs. radiofrequency ablation nephrectomy in the full and exact match cohorts
for the management of small renal masses
2
1
3
Raees Cassim , Anand Swaminath , Jen Hoogenes , Oleg Mironov , Braden Full cohort After exact match
1
1
Millan , Edward D. Matsumoto , Anil Kapoor 1 AS Nephrectomy AS Nephrectomy
1
1 Division of Urology, Department of Surgery, McMaster University,
Hamilton, ON, Canada; Department of Oncology, Faculty of Health n 205 172 53 57
2
3
Sciences, McMaster University, Hamilton, ON, Canada; Department of Demographic and clinical covariates
Radiology, Faculty of Health Sciences, McMaster University, Hamilton, Age (years), mean 65.1 63.1 63.1 64.3
ON, Canada Sex, male (%) 67.3 65.1 77.2 77.2
Introduction: The potential of ablative technologies in replacing surgery
for the treatment of small renal masses (SRMs) ≤4 cm is unclear. Our ECOG (%)
objective was to evaluate the feasibility and toxicity of stereotactic body 0 56.6 65.7 75.4 75.4
radiation therapy (SBRT) and radiofrequency ablation (RFA) for SRMs to ≥1 9.8 7.0 3.5 3.5
determine the utility of a future full-scale multicenter trial. Unknown/ 33.7 27.3 21.1 21.1
Methods: Patients scheduled for SRM treatment at a single academic missing
center were approached for this pilot trial, with the aim of recruiting 24
patients. Participants were randomized to SBRT or RFA. Imaging (com- Biopsy, yes (%) 59.5 72.7 47.4 47.4
puted tomography or magnetic resonance imaging) is completed at three, Histology
six, nine, and 12 months post-procedure. Crossover, if ineligible for treat- Clear-cell (%) 20.5 66.4 38.6 38.6
ment after randomization, was allowed. Biopsies were completed prior
to the procedure and at 12 months. SBRT included an initial simulation Papillary (%) 14.8 13.6 5.3 5.3
session and a single image-guided treatment session with a prescribed Chromophobe (%) 0 6.4 0 0
dose of 25 Gy. RFA was conducted by either percutaneous or laparoscopic Benign (%) 45.9 0.8 0 0
access with two cycles of eight minutes duration each upon reaching
target temperature. Other (%) 4.9 6.4 0 0
Results: Twenty-four patients were recruited and randomized over 18 No histology/ 13.9 6.4 56.1 56.1
months (SBRT=11; RFA=13). Fourteen had SBRT, eight RFA, and two Non-diagnostic/No
became ineligible. The median age for all patients was 67 years (53,85) biopsy (%)
and 17 were male. Seventeen patients had clear-cell renal cell carcin- Outcomes
oma (RCC), six had papillary RCC, and one had chromophobe RCC.
All patients had T1a disease. Mean procedure length (minutes) for SBRT Overall survival
and RFA was 15.5±7.4 and 10.5±3.9, respectively. Two of five patients Dead 7 3 2 2
(four SBRT, one RFA) who had a 12-month biopsy demonstrated viable
tumor (two SBRT). An additional five patients (one RFA, four SBRT) had 5-year overall 96.0 98.1 94.8 95.7
nine-month imaging demonstrating no tumor growth. Additional data Survival
are not yet available for the remaining patients. An early grade 2 flareup Probability (%)
occurred in one SBRT patient. Event-free survival (composite)
Conclusions: Recruitment and randomization of patients with SRMs is Event (n) 8 9 2 4
feasible on a timeline that allows for regular followups and imaging.
Thus far, both treatments have been shown to have an excellent short- 5-year survival 96.0 95.4 96.0 92.7
term safety profile. Probability (%)
AS: active surveillance; ECOG: Eastern Cooperative Oncology Group.
MP-3.7
A matched analysis of active surveillance vs. nephrectomy for Results: We identified 377 SRM patients, of which 205 were managed
small renal masses by AS and 172 by nephrectomy. The cohort was balanced after matching
Douglas Cheung , Lisa J. Martin , Maria Komisarenko , Kristen McAlpine , (n=110) (Table 1): age 64 years, 77% male, and 75% ECOG 0. In each
1
1
1
1
2
Shabbir M. Alibhai , Antonio Finelli 1 arm, 47% of patients had a biopsy, with predominantly clear-cell histol-
1 Division of Urology, Department of Surgery, Princess Margaret Cancer ogy. In the matched cohort, the predicted five-year OS was 95.7% for
2
Centre, University Health Network, Toronto, ON, Canada; Department nephrectomy and 94.8% for AS (p=0.84; hazard ratio [HR] nephrectomy
of Medicine, University Health Network, Toronto, ON, Canada vs. AS 0.83, 0.13–5.32), while the EFS was 92.7% and 96.0%, respectively
Introduction: While studies have shown that patients with a small renal (p=0.47; HR nephrectomy vs. AS 1.88, 0.35–10.15).
mass (SRM) managed on active surveillance (AS) maintain excellent Conclusions: In SRM patients well-matched for age and comorbidity, we
metastasis-free (MFS) and cancer-specific survival (CSS), observed differ- observed much higher five-year OS and EFS rates for AS than those previ-
ences in overall survival (OS) may be explained by older/more comorbid ously reported, with point estimates that were comparable to nephrec-
patients selecting AS. Few studies have evaluated the outcomes of AS vs. tomy. Furthermore, our matched characteristics approximate the treatment
primary intervention in clinically balanced patient groups. arms of contemporary cohorts (i.e., the patient population equally eligible
Methods: Patients with a SRM (≤4 cm T1a) aged 55–75 were identified for AS or primary intervention), suggesting that AS is a safe management
from our institutional database (2000–2020). Those with a prior can- strategy in younger, healthier patients.
cer history/family history or undergoing radiofrequency ablation were
excluded. Demographic and clinical information were extracted to assess
OS and a composite event-free survival (EFS) outcome, which included
OS, CSS, MFS, progression, or systemic therapy, using Cox proportional
hazards models. To better adjust for clinical characteristics, patients
receiving AS versus nephrectomy were exact-matched on age, sex, Eastern
Cooperative Oncology Group (ECOG) score, biopsy status, and histology.
S42 CUAJ • June 2022 • Volume 16, Issue 6(Suppl1)