Partial nephrectomy (PN) and cryoablation (CA) for organ-confined renal cell carcinoma tumors less than 2 cm in diameter are associated with similar survival outcomes, according to a new study. For tumors 2–4 cm in diameter, PN may offer advantages over CA.

Using the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) program database, Xinyang Liao, MD, of West China Hospital, Sichuan University, Sichuan, China, and colleagues identified 18,512 patients with T1a N0M0 renal cell carcinoma (RCC) treated with PN (93.9%) or CA (6.1%). In a propensity score matched cohort of 1044 PN and 1044 CA cases, the investigators found no significant difference between the treatment approaches in cancer-specific mortality (CSM) and overall mortality (OM) among patients with tumors 2 cm or smaller in diameter, Dr Liao and colleagues reported in Cancer Epidemiology.

Among patients with 2–3 cm tumors, PN and CA were associated were similar CSM, but cryoablation was associated with a significant 2-fold higher risk of OM compared with PN. Among patients with 3–4 cm tumors, CA was associated with a significant 3.8- and 2.2-fold increased risk of CSM and OM, respectively, compared with PN.

In an acknowledgement of study limitations, the authors pointed out that the SEER database does not differentiate surgical approaches such as percutaneous, laparoscopic, and robotic-assisted techniques. In addition, to include patients of all ages, they used the overall SEER database rather than the Medicare-linked database. As a result, they were unable to collect information about preexisting conditions and Charlson Comorbidity Index score.

“Despite the limitations, this is the first study to compare survival outcomes of PN and CA,” Dr Liao and colleagues wrote. “We found CA and PN yield equal survival outcomes for patients with RCC less than 2 cm. However, PN yields superior survival outcomes for RCC larger than 2 cm.”

Reference

Liao X, Qiu S, Wang W, et al. Partial nephrectomy vs cryoablation for T1a renal cell carcinoma: A comparison of survival benefit stratified by tumour size. Cancer Epidemiol. 2019; published online ahead of print.

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