No survival falloff with use of minimally invasive surgery in early-stage kidney cancer

Gregory B. Auffenberg, MD

There was no overall survival (OS) difference when using minimally invasive surgery (MIS) compared with open surgery for the treatment of patients with early-stage kidney cancer, according to findings from a retrospective, population-based cohort study published in the Journal of Urology.

Multivariable modeling showed no variation in OS (HR 0.94; 95% CI, 0.84-1.06) or disease-specific survival (HR, 0.96; 95% CI, 0.83-1.11) between the 2 treatment modalities. There was also no difference observed in the rate of second kidney cancer surgery associated with MIS or open surgery. However, the use of postoperative therapy was higher in the MIS cohort.

“Our findings inform practice in an area where, to date, there has been no prospective randomized comparison of oncologic outcomes,” Gregory B. Auffenberg, MD, department of urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, and coinvestigators wrote.

“We found no association between type of surgery and overall survival, disease-specific survival, or rate of second kidney cancer surgery,” added Auffenberg et al. “MIS recipients received more postoperative systemic therapy, which could represent a disparate cancer-specific outcome associated with MIS requiring further investigation.”

For their retrospective analysis, Auffenberg et al used data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER)–Medicare-Linked Database. The analysis included 5150 patients diagnosed between 2004 and 2013 with early-stage, nonurothelial kidney cancer. Patients were aged ≥66 years; had nonmetastatic, T1N0 (<7 cm) disease; and received surgical resection within a year of diagnosis.

The investigators excluded patients who had received neoadjuvant therapy, had bilateral tumors, did not have a known date of diagnosis, were diagnosed at autopsy, or were diagnosed on death certificate. In the final population, 3062 patients had received MIS and 2088 patients had received open surgery.

Among the MIS cohort, the median interval from diagnosis to surgery was 21 days, compared with a median interval of 19 days for the open surgery group. Over time, MIS was increasingly the more common treatment choice. Clear cell histology was more common (59.5% vs 53.4%; P <.001) among those who underwent MIS. The MIS cohort also had a higher rate of radical nephrectomy at 66.9% compared with 59.3% among the open surgery group (P <.001).

At a median follow-up of 57.2 months (IQR, 32.3-86.9), the all-cause mortality rate was 26.4% (n = 551) in the open surgery cohort, compared with 21.2% (n = 649) in the MIS cohort. The cancer-specific mortality rate was 4.9% (n = 101) versus 3.3% (n = 102), respectively.

In the open surgery group, 6.2% (n = 130) of patients received subsequent systemic cancer therapy, compared with 6.9% (n = 214) of the MIS cohort. After accounting for covariates, receiving MIS was linked to a significantly higher likelihood of being treated with secondary systemic cancer therapy (HR, 1.31; 95% CI, 1.09-1.59).

“In the absence of a prospective, randomized trial, our population-based evaluation, inclusive of patients undergoing operations in varied practice environments, represents a meaningful way to compare outcomes after MIS and open kidney cancer surgery,” concluded Auffenberg, et al.

Reference

Auffenberg GB, Curry M, Gennarelli R, et al. Comparison of cancer specific outcomes following minimally invasive and open surgical resection of early stage kidney cancer from a national cancer registry. J Urol. 2020;203(6):1094-1100. doi: 10.1097/JU.0000000000000741