Which surgery is recommended for urachal carcinoma?

In patients with nonmetastatic urachal carcinoma (UrC), radical cystectomy (RC) does not significantly improve cancer-specific mortality rates compared to partial cystectomy (PC), according to a study presented at the recently concluded Annual Congress of the European Association of Urology (EAU 2022). Partial cystectomy remains the optimal surgical choice in this patient population.

To compare the two surgical approaches, the researchers retrieved data from the Surveillance, Epidemiology, and End Results Program database, with the period of investigation spanning from 2004 to 2016. A total of 392 eligible UrC patients were analysed, all of whom were ≥18 years of age. The outcome of interest was cancer-specific mortality.

Majority (86 percent; n=337) of the participants underwent PC, which remains the standard of care for UrC. In comparison, only 14 percent (n=55) were treated with RC. From 2004 to 2016, the use of RC dropped by a total of 6 percent, a decline that proved to be significant (p=0.007). [EAU 2022, abstract A0630]

Radical surgery was more likely to be performed in patients with higher-stage disease that had spread beyond the urachus (58 percent vs 29 percent; p=0.03) and who harboured higher-grade tumours (56 percent vs 29 percent; p<0.001). Those who had undergone pelvis lymph node dissection were also more likely to receive RC (84 percent vs 55 percent; p<0.001).

Nevertheless, no meaningful impact on outcome was reported. Five-year CSM rates did not significantly differ between the RC and PC groups both before (60 percent vs 71 percent, respectively; multivariable hazard ratio [HR], 1.37; p=0.2) and after (69 percent vs 70 percent, respectively; multivariable HR, 1.05; p=0.9) inverse probability of treatment weighting.

“In consequence, PC use should continue, unless contraindicated due to either extension of primary tumour or insufficient bladder capacity,” the researchers said.

Better with robots?

Another study presented at EAU 2022 looked at whether robotic-assisted PC (RAPC) could outperform the standard open PC (OPC) with an en-bloc resection of the umbilicus and the remnant urachus. Results showed comparable feasibilities and efficacies, but with a slight safety signal associated with RAPC. [EAU 2022, abstract A0629]

To comparatively evaluate short-term oncological and safety outcomes, the researchers conducted a retrospective analysis using data from 55 patients (median age 54 years) with localized UrC. Forty-seven patients underwent OPC, while only eight were subjected to RAPC. All patients were also treated with external beam radiation.

Over a median follow-up of 40 months, the researchers estimated a 2-year overall survival of 73 percent for RAPC and 90 percent for OPC using Kaplan-Meier analysis. Corresponding values for recurrence-free survival were 60 percent and 66 percent. There were no statistically significant differences between survival measures, implying comparable surgical efficacies.

The same was true for surgical margin, which was 13 percent for both OPC and RAPC. Both approaches had generally comparable safety profiles, with complications occurring in 25 percent and 11 percent of RAPC and OPC patients, respectively (p=0.27).

In contrast, two patients developed port-site recurrence (PSR) after RAPC. “The PSR rate of 25 percent after RAPC should prompt us to be cautious to recommend RAPC as no such recurrences were seen using OPC,” the researchers said.