Comparative analysis of the results of surgical and radiation treatment of stage I kidney cancer

Abstract

   Purpose of the study: To conduct a comparative assessment of the results of surgical and radiation treatment of patients with stage I renal cell carcinoma (RCC) in terms of overall survival (OS), progression-free survival (PFS), local control and changes in renal function.   Material and methods: From 2011 to 2022 170 patients with stage I RCC were treated at the Chelyabinsk Regional Clinical Center of Oncology and Nuclear Medicine. We conducted a retrospective study of their treatment results. The first group — 115 patients who underwent surgical treatment of T1N0M0 kidney cancer (mainly in the amount of kidney resection — 85 people), the second group — 55 patients with verified T1N0M0 renal cell carcinoma who underwent stereotactic radiation therapy (SBRT) up to 30–45 Gy in 3 fractions using CyberKnife. SBRT was performed mainly for the treatment of a primary kidney tumor, in 7 cases — for a recurrence of kidney cancer, including 1 patient with recurrent tumors in both kidneys. The average age of patients in the surgery group was 73 years, in the SBRT group — 69.9 years. The average tumor diameter in the operation group was 4.3 cm, in the SBRT group it was 3.5 cm.   Results: The median OS in the surgery group was 121 months, but it was not achieved in the SBRT group, since most patients are alive at the time of the study. 1‑year OS in the surgery group and SBRT was comparable (98.9 % and 95.1 %, respectively), but 5‑year OS in the surgery group was significantly higher — 90.2 % vs. 70 % in the SBRT group (p < 0.05). The same trend was noted in the assessment of PFS. In the surgery group, 4 patients out of 115 (3.5 %) had a recurrence in the tumor bed, in all cases after kidney resection, after 28 months in average. In the SBRT group, 42 patients (75 %) according to RECIST 1.1 criteria 6 months after SBRT showed stabilization of the process, in 20 % of cases (11 patients) — a partial response, in 5 % (3 patients) — progressed disease. 1‑year local control was 96.4 %, 1‑year cancer‑specific survival in both groups was 100 %. Renal toxicity was recorded in 38 patients (33 %) in the surgery group and in 10 patients (18 %) in the radiotherapy group 6 months after treatment. On average, glomerular filtration rate decreased by 25 % in the surgery group and by 18 % in the radiotherapy group. We have not noted a single case of a pronounced decrease in GFR, which would require dialysis.   Conclusion: Surgery remains the main treatment option for T1N0M0 kidney cancer, but if there are contraindications to surgery, SBRT may be the best option for inoperable patients.