Introduction:

Over the past two decades, the incidence of kidney cancer has more than doubled, driven mostly by the incidental detection of clinical T1 renal masses. Historically, the standard treatment for clinical T1 kidney tumors has been surgical removal, either through a partial or radical nephrectomy. However, thermal ablation and active surveillance have become viable options, especially for small renal masses (SRM) ≤4 cm in size of which 20-30% are benign and a very low percentage metastasize. Renal mass biopsy (RMB) can yield accurate pathologic information that can help guide clinical decision-making. We hypothesize that this information may further improve the decision-making experience for patients given the multitude of management choices available. In this study, we examine the impact of renal mass biopsy on decisional conflict among patients presenting with clinical T1 renal masses suspicious for kidney cancer.

Methods:

From October 2018–June 2022, we enrolled patients with new clinical T1 renal masses onto GRADE-SRM (Genomic Risk Assessment and Decisional Evaluation for Small Renal Masses), a comparative, non-randomized hybrid trial that evaluates the decision-making experience and cancer genomics. For this study, patients completed surveys on their health status, decision-making behavior, and experiential outcomes. As the primary experiential outcome, patients completed the decisional conflict scale (DCS), a validated instrument that measures patient perceptions of uncertainty and effective decision-making. Factors associated with RMB were assessed first using modified Poisson analyses and described using relative risks. We then performed a difference-in-difference analysis to compare the change in total DCS and DCS subdomains (i.e., uncertainty, informed, values clarity, support, effective decision-making) between their initial visit (T0) and a few weeks later (T1) by receipt of RMB, adjusted for age, gender, race, mass diameter, mass type, nephrometry score, bilaterality, comorbidity burden, and performance status.

Results:

Among 261 subjects, 29.5% underwent RMB. Mean age was 62.2 years old (SD 11.3), and 61% of patients were male. The sample was relatively healthy with ECOG 0 in 68%, eGFR ≥60 in 75%, and no anticoagulation in 90% of patients. Receipt of RMB was more common for patients with masses >4 cm in size vs. 0-2 cm (RR 1.82, 95% CI 1.01–3.28), high nephrometry score vs. low (RR 1.89, 95% CI 1.07–3.37), and ECOG ≥2 vs. 0 (RR 2.18, 95% CI 1.09–4.33). On unadjusted analysis, patients undergoing RMB had a significant decrease in total DCS between T0 and T1 compared to patients not undergoing RMB (Figure 1). On multivariable analysis, change in total DCS did not differ significantly by RMB status (p=0.095) but did differ significantly by RMB status for DCS uncertainty (p=0.040) and effective decision-making (p=0.030) subdomains.

Conclusion:

Beyond providing pathological information, renal mass biopsy may reduce decisional conflict by providing greater certainty over the diagnosis and facilitating more effective decision-making. These results highlight the potential benefits of renal mass biopsy in improving the patient experience and could support its greater use in the evaluation of patients presenting with small renal masses. Future research will focus on how renal mass biopsy impacts the ultimate treatment modality and patient-reported outcomes.

Funding: This work was supported by funding from the National Institutes of Health (UNC Integrated Translational Oncology Program T32-CA244125 to UNC/khg) and UNC Lineberger Comprehensive Cancer Center UNCseq v2.