Recent findings support the notion of metastasectomy being linked with an overall survival (OS) benefit for patients with metastatic renal cell carcinoma (mRCC). However, researchers noted that metastasectomies not achieving complete resection of all known lesions are likely without OS benefit.
For a paper published in Clinical Genitourinary Cancer, Florian Posch, MD, PhD, and colleagues conducted an analysis of OS in 106 patients with mRCC with metachronous metastasis, of whom 34% were treated with metastasectomy and 66% with medical therapy alone.
Fewer Bilateral Lung Metastases and Longer Disease-Free Intervals
Following metastasectomy, median time to progression was 0.7 years (25th-75th percentile: 0.3-2.7). After a median follow-up of 6.2 years and 63 deaths, 5-year OS estimates were 41% and 22%, respectively, in the metastasectomy and medical therapy groups. “Patients undergoing metastasectomy had a significantly higher prevalence of favorable prognostic factors, such as fewer bilateral lung metastases and longer disease-free intervals between nephrectomy and metastasis diagnosis,” the study authors wrote.
However, the researchers noted that the favorable relationship between metastasectomy and OS became much weaker after propensity score weighting for these differences and adjusting for immortal time bias. In the metastasectomy and medical therapy groups, propensity-score-weighted 5-year OS estimates were 24% and 20%, respectively. “The benefit of metastasectomy was confined to patients who achieved complete resection of all known metastases,” the study authors wrote.
Investigators concluded that this research supports their hypothesis that for patients with mRCC, metastasectomy is linked with an OS benefit. “Metastasectomy benefit appears to be greatest in patients with only one metastatic lesion,” the study authors wrote. “These results can inform cancer specialists and patients when planning comprehensive, multi-disciplinary treatment for mRCC.”