Pathological concordance and surgical outcomes of sporadic synchronous unilateral multifocal renal masses treated with partial nephrectomy, "Beyond the Abstract," by Robert Uzzo, MD, FACS, et al

BERKELEY, CA (UroToday.com) - Multifocal renal masses represent a unique subset of patients presenting with presumed renal cancer. In fact, previous reports have demonstrated that between 5-25% of patients undergoing surgery for a presumed single renal mass possess multifocal disease.[1, 2] Though the rates of pathologic concordance for patients presenting with bilateral masses has been reported to be high, pathologic concordance rates for those patients presenting with unilateral disease is poorly understood.[3, 4, 5] In the largest known report of patients presenting with bilateral synchronous renal masses analyzing malignant, histologic, and grade concordance, Rothman et al. demonstrated a 99%, 93%, and 83% rate of concordance using a SEER cohort.[4]

Understanding rates of benign and malignant pathologic disease in patients presenting with unilateral multifocal renal masses (UMRM) is an integral step that provides more data to inform patient treatment decision-making. Unlike the high rates of pathologic concordance observed with bilateral cases, our findings demonstrate a notably low rate of concordance in UMRMs with regard to tumor malignancy, histology, and grade.[6] In an analysis of 97 patients with UMRMs at our institution, malignant concordance was observed in 77.2% with a benign concordance rate of only 48.6% and a histologic grade concordance of 58.8%. While a majority of patients (85%) underwent an open-nephron sparing technique, no patients in our cohort required intraoperative conversion to radical nephrectomy. Clear-cell and papillary RCC tumors were encountered most frequently (36.1% and 24.5%, respectively). In summary, we demonstrate that patients undergoing planned nephron sparing surgery for UMRMs can undergo surgery with acceptable intraoperative results and a limited complication profile.

Furthermore, our study has important implications in both treatment decision-making and management planning for patients presenting with UMRMs. Current AUA guidelines indicate the management of the small renal mass ought to ensure oncologic efficacy, preserve renal parenchyma, and attempt a minimally invasive approach, if feasible.[7] However, in patients where surgery may be prohibitive due to competing medical risks, renal mass biopsy is often undertaken in order to further guide treatment strategy and decide candidacy for active surveillance protocols.[8, 9] Importantly, single renal mass biopsy in a patient presenting with UMRMs may be insufficient to guide treatment strategy due to the observed low rates of pathologic concordance.

Patients presenting with enhancing, synchronous UMRMs pose a management conundrum for the urologic oncologist. With current AUA guidelines recommending a nephron-sparing approach for the surgically amenable cT1 renal mass, our study demonstrates that partial nephrectomy may be undertaken safely and with acceptable oncologic results in select patients with multifocal renal tumors. Importantly, our findings highlight low rates of malignant, histologic, and grade concordance in patients with unilateral multifocal disease – a finding in stark contrast to bilateral cases. Our findings have important implications for treatment planning that should be incorporated into patient counseling for the subset of patients with multifocal renal tumors.

References:

  1. Li, Q.L., et al., Optimal margin in nephron-sparing surgery for renal cell carcinoma 4 cm or less. Eur Urol, 2003. 44(4): p. 448-51.
  2. Wang, R., et al., Accuracy of percutaneous core biopsy in management of small renal masses. Urology, 2009. 73(3): p. 586-90; discussion 590-1.
  3. Boorjian, S.A., et al., The impact of temporal presentation on clinical and pathological outcomes for patients with sporadic bilateral renal masses. Eur Urol, 2008. 54(4): p. 855-63.
  4. Rothman, J., et al., Pathologic concordance of sporadic synchronous bilateral renal masses. Urology, 2008. 72(1): p. 138-42.
  5. Patel, A.R., et al., Bilateral synchronous sporadic renal tumors: pathologic concordance and clinical implications. Urology, 2011. 78(5): p. 1095-9.
  6. Simhan, J., et al., Pathological concordance and surgical outcomes of sporadic synchronous unilateral multifocal renal masses treated with partial nephrectomy. J Urol, 2013. 189(1): p. 43-7.
  7. Campbell, S.C., et al., Guideline for management of the clinical T1 renal mass. J Urol, 2009. 182(4): p. 1271-9.
  8. Lane, B.R., et al., Renal mass biopsy--a renaissance? J Urol, 2008. 179(1): p. 20-7.
  9. Smaldone, M.C. and R.G. Uzzo, Active surveillance: a potential strategy for select patients with small renal masses. Future Oncol, 2011. 7(10): p. 1133-47.

Written by:
Jay Simhan,a Daniel Canter,b Alexander Kutikov,c and Robert G. Uzzoc as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.

aDivision of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Temple University School of Medicine, Philadelphia, Pennsylvania; bDepartment of Urology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia; cDivision of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Temple University School of Medicine, Philadelphia, Pennsylvania

Pathological concordance and surgical outcomes of sporadic synchronous unilateral multifocal renal masses treated with partial nephrectomy - Abstract

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