The majority of sporadic RCC patients present with unilateral disease. Synchronous bilateral RCC at presentation occurs in approximately 3% of patients1.
It is important to remember that there is pathological heterogeneity in sporadic synchronous renal tumors. In a study assessing 112 patients with 291 tumors, the malignant concordance was 92%, and pathological concordance was 67%, with grade concordance of 63%2.
The demonstrated prognosis of patients with synchronous and unilateral RCC is quite similar3 (Figure 1), as been shown in a large international multicenter study with over 10,000 patients from 12 academic centers.
Figure 1 – Kaplan–Meier survival estimates for: a) patients with synchronous bilateral and unilateral RCC (P = 0.63); and b,) patients with synchronous bilateral RCC and at least one multifocal primary tumor to those without (P = 0.60)3:
In the next part of his talk, Dr. Leibovich moved on to discuss the possible options for the management of bilateral RCC. These include:
- Bilateral nephrectomy
- Unilateral nephrectomy and nephron-sparing surgery or focal therapy
- Bilateral nephron-sparing preservation with surgery, ablative therapy, or active surveillance
- Off-label systemic therapy or systemic therapy trial
Dr. Leibovich believes the thought process for treating bilateral tumors is quite similar to treating unilateral tumors, with consideration of the oncologic threat for each side, and host factors, including the patient’s renal function.
Treatment of the more oncologically threatening side should be done first, according to Dr. Leibovich, and one should consider whether a staged or simultaneous procedure should be performed. The surgical approach and modality vary between surgeons, and surgeons should perform the procedure in a way that suits their comfort level.
The probability of aggressive histology rises concordantly with the size of the tumor and is more prevalent in males than in women4.
Figure 2 - The predicted percentage of patients with malignant and aggressive histology based on tumor size4:
Active surveillance is also an option for small renal masses5. There are several patient-related factors and tumor factors favoring this approach over surgical intervention, as seen in table 1.
Table 1 - Patient and tumor-related factors favoring active surveillance versus intervention5:
Next, Dr. Leibovich discussed the comparison of partial nephrectomy to percutaneous ablation for cT1 renal masses. He described a study comparing 1424 cT1a and 379 cT1b renal masses undergoing surgery and partial nephrectomy. The results showed that recurrence-free survival was similar for partial nephrectomy and percutaneous ablation patients. Metastases-free survival was superior for partial nephrectomy and cryoablation patients when compared with radiofrequency ablation for cT1a patients6. Comparison studies have also shown no significant difference in renal function between patients treated with a partial nephrectomy and ablative therapy three months after procedure 7.
Figure 3 - Metastases-free survival after partial nephrectomy, percutaneous radiofrequency ablation, and percutaneous cryoablation for patients with cT1a biopsy-proven renal cell carcinoma6:
When comparing simultaneous vs. staged partial nephrectomies in patients with bilateral synchronous solid renal tumors, no difference in clinicopathologic features was noted. However, simultaneous procedures had fewer complications, including urine leak and shorter time in the hospital8.
Next, Dr. Leibovich discussed the role of neoadjuvant systemic therapy prior to surgery. In a study comparing 47 patients with neoadjuvant sunitinib to 78 patients without neoadjuvant therapy, there was a 20% reduction in tumor volume with sunitinib, with no difference between groups in the ischemia time, complication rate, and change in GFR9. In another similar study with 13 cases where partial nephrectomy was considered not feasible, neoadjuvant pazopanib resulted in 6 patients being able to get a partial nephrectomy10
Concluding his talk, Dr. Leibovich stated that when treating patients with bilateral RCC, an individualized approach is required, and the goals of maximizing oncologic control and renal function simultaneously should be met. Outcomes are not worse, but surveillance should be more intense due to the risk of metachronous new tumors. Lastly, it is critical to embrace multimodal approaches inclusive of ablative technologies and perhaps systemic therapy in the appropriate settings.
Presented by: Dr. Bradley C. Leibovich, MD, Chair, and Professor of Urology, Mayo Clinic, Rochester, Minnesota
Written by: Hanan Goldberg, MD, MSc, Assistant Professor, Urology Department, SUNY Upstate Medical University, Syracuse, NY, USA, @GoldbergHanan at the 2020 Society of Urologic Oncology Annual Meeting – December 2-5, 2020 – Washington, DC
References:
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3 Klatte T, Wunderlich H, Patard JJ, et al. Clinicopathological features and prognosis of synchronous bilateral renal cell carcinoma: an international multicentre experience. BJU Int 2007; 100(1): 21-5.
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9. McDonald ML, Lane BR, Jimenez J, et al. Renal Functional Outcome of Partial Nephrectomy for Complex R.E.N.A.L. Score Tumors With or Without Neoadjuvant Sunitinib: A Multicenter Analysis. Clinical genitourinary cancer 2018; 16(2): e289-e95.
10. Rini BI, Plimack ER, Takagi T, et al. A Phase II Study of Pazopanib in Patients with Localized Renal Cell Carcinoma to Optimize Preservation of Renal Parenchyma. The Journal of urology 2015; 194(2): 297-303.