Impact of Tissue Biopsy Prior to Systemic Therapy on Treatment Decisions and Early Outcomes in Metastatic Renal Cell Carcinoma

Background: Metastatic renal cell carcinoma (mRCC) is a biologically heterogeneous malignancy with evolving systemic treatment options. Tissue biopsy is traditionally recommended for histological confirmation and therapeutic planning; however, its necessity prior to initiation of systemic therapy remains debated, particularly when delays in treatment initiation may cause higher loss to follow-up in the biopsy group and the system-delay in a resource-limited setting. Objectives: To evaluate the role of tissue biopsy prior to initiation of palliative therapy in metastatic renal cell carcinoma with respect to treatment selection, treatment initiation delay, early clinical outcomes, and follow-up status. Methods: This retrospective observational study included 68 patients with metastatic renal cell carcinoma who received palliative systemic therapy. Patients were categorized into biopsy (n=40) and non-biopsy (n=28) groups. Data collected included demographic characteristics, IMDC risk stratification, treatment modality, time to treatment initiation, early treatment response, and follow-up status. Comparisons were performed using Chi-square or Student’s t-test, with a p-value 0.05). Treatment selection differed significantly between groups. Immunotherapy or combination therapy was used in 35.0% of patients in the biopsy group compared to 14.3% in the non-biopsy group (p=0.03), while TKI monotherapy was more frequent in the non-biopsy group (50.0% vs 30.0%; p=0.04). The mean time to initiation of palliative therapy was significantly longer in patients undergoing biopsy (18.6 ± 6.4 days) compared to those without biopsy (10.2 ± 4.8 days; p