Nephrectomy shown to be beneficial in metastatic kidney cancer patients treated with systemic therapy

New findings suggest that nephrectomy (Nx) significantly improved progression-free survival and overall survival in patients with metastatic renal cell carcinoma (mRCC) treated with immunotherapy or targeted therapy when compared to no nephrectomy (non-Nx). The retrospective study was published in Scientific Reports.

Cytoreductive nephrectomy (CNx) is often recommended as part of an integrated therapeutic management strategy for mRCC to reduce the potential tumor burden, as well as to control cancer-related symptoms, such as hemorrhage, pain, and paraneoplastic syndrome.

In addition to systemic treatment, CNx has also been proven to improve prognosis of mRCC, although the survival benefit of Nx with targeted therapy (TT) is not well defined.

Sung Han Kim, MD, and colleagues, from the Research Institute and Hospital of the National Cancer Center in Goyang, Korea, evaluated the prognostic significance of Nx in patients with mRCC through stratification according to types of systemic therapy (immunotherapy [IT] or TT) or metastatic types (synchronous or metachronous). In addition, two widely used prognostic risk models were used: The Memorial Sloan-Kettering Cancer Center (MSKCC) and International Metastatic Renal Cell Carcinoma Database Consortium (IDMC), also known as Heng, which rates risk as favorable, intermediate, and poor.

A total of 292 mRCC patients were enrolled; 61.6% of patients underwent Nx and 38.9% of patients did not (non-Nx).

Among patients receiving first-line systemic therapy during the 15-year study period, 54.8% were treated with TT (including sunitinib, sorafenib, pazopanib, and temsirolimus), and 45.2% were treated with IT, such as interferon-alpha and interleukin-2.

Patient records were used to obtain baseline data such as age, body mass index, ECOG–performance status, TNM stage, cell histology, Fuhrman nuclear grade, and survival outcomes. The radical nephrectomy (RNx) or CNx procedure was performed by a single surgeon; histological confirmation of RCC was performed via examination of biopsy specimens.

During a median 10.0 months of treatment and 16.6 months of follow-up, the objective response rate was 17.5% and disease control rate was 63.4% after first-line therapy.

The median progression-free survival (PFS) and overall survival (OS) were 2.0 months and 10.0 months for patients treated with IT, and 5.0 months and 13.0 months for TT, respectively.

The Nx group had significantly longer PFS/OS (6.0/30.0 months) than the non-Nx group (3.0/8.0 months, P < 0.001).

Those with intermediate and poor risks treated with TT had better prognostic effects on both PFS (9.0 and 4.0 months) and OS (32.0 and 9.0 months) than IT (PFS: 4.0 and 2.0 months; OS: 26.0 and 6.0 months). A small subset of patients (11.6%) received IT first, followed by TT. The patients in this IT to TT group had the best PFS/OS among all MSKCC and Heng risk groups (P < 0.05).

Patients in the Nx group had significantly prolonged PFS/OS compared to the non-Nx group (P < 0.05), despite more favorable baseline characteristics of patients undergoing Nx.

The intermediate- and poor-risk patients using either model showed significantly longer PFS and OS in the Nx group than in the non-Nx group (P < 0.05).

After stratification of prognostic risks and systemic therapies, PFS and OS were not significantly different between patients in the Nx and non-Nx groups.

In synchronous and metachronous mRCC patients, the Nx group had longer PFS and OS than the non-Nx group, even after considering each systemic therapy and prognostic model. Additional findings showed that metastatic types did not significantly affect the prognostic survival differences between patients who underwent Nx and those who did not.

The authors believe that this implied that Nx was beneficial for both types of mRCC when the patient’s surgical condition and disease status allowed it, and thus, was a significant factor for better survival in mRCC.

The investigators acknowledge that some limitations of this study include the retrospective design with a small number of poor-risk patients. The intraoperative measures and further analyses of systemic agents have also not been accounted in the survival rate of Nx group.

“This is an evidence-based retrospective study providing the positive aspects of CNx in the TT era. A carefully selected group of patients with synchronous mRCC can obtain a clinical benefit with survival gain after combinational local surgery such as metastasectomy or radiation therapy with systemic TT,” the authors concluded.

To read more about this study, click here.