乌鸦传媒

CHICAGO -- Delaying surgery for small renal tumors for up to a year did not adversely affect survival compared with early surgery, a retrospective review of a large cancer database showed.

The analysis of over 14,000 patients with tumors ≤4 cm showed no significant difference in overall survival whether surgery occurred within 30 days or beyond 6 months. A sensitivity analysis showed the lack of difference extended to patients who had surgery beyond 12 months, reported Wei Shen Tan, MD, PhD, of University College London, and colleagues.

The results added to previous evidence supporting active surveillance for many patients with small renal tumors, as reported here at the meeting.

"Bearing in mind the limitations of a retrospective analysis, we report that delayed and immediate nephrectomy for clinical T1a renal cell carcinoma confers comparable long-term overall survival," said Tan. "We hypothesize that a period of active surveillance is safe to allow identification of renal masses which will benefit from surgical resection."

In a presented here, surgical wait times that exceeded 6 months did not significantly affect pathologic upstaging, recurrence-free survival (RFS), or overall survival (OS) associated with cT1-2 tumors. However, longer wait times had an adverse impact on OS in patients with T3-4 tumors but did not affect pathologic upstaging or RFS, said lead author Benjamin Shiff, MD, of the University of Manitoba in Winnipeg.

Following the two presentations, session co-moderator Alejandro Rodriguez, MD, of Chesapeake Urology in Columbia, Maryland, said these results "really support the management strategy of active surveillance for small renal masses." Tan noted how the National Comprehensive Cancer Network guidelines include active surveillance as an option for tumors ≤2 cm, whereas his and Shiff's studies included patients with tumors as large as 4 cm.

"A lot of times I think it is quite useful to monitor these patients, possibly get a biopsy, and just wait and see," suggested Tan.

Without commenting directly on either study, Benjamin Davies, MD, of the University of Pittsburgh Medical Center, told 乌鸦传媒 that "active surveillance is definitely a space in urology that we need to be better at. We definitely should be doing more active surveillance in small renal tumors. We have a problem with overtreatment of both prostate cancer and kidney cancer."

Ongoing Debate

The two studies continued the debate on how aggressively small renal masses should be treated. A recent report from an active surveillance program for newly diagnosed kidney cancer showed a 7-year cancer-specific survival of 99-100% with or without immediate surgery for renal tumors ≤4 cm.

In this first analysis, Tan and co-authors analyzed data from 2005-2010 on patients ≤70 with a Charlson Comorbidity Score of 0 and a diagnosis of cT1aN0Mo renal cell carcinoma from the . The query selected 14,677 patients who had partial or radical nephrectomy and compared those with a surgical wait time ≤30 days (immediate surgery) versus ≥180 days (late).

The cohort had a median age of 55 and median follow-up of 7 years, and the primary outcome was OS. Tan said 14,060 patients had immediate surgery after diagnosis and 617 had late surgery.

Investigators performed an inverse probability of treatment weighting analysis adjusted for multiple clinical and demographic factors. The calculations produced an OS hazard ratio of 0.83 for immediate versus late surgery, which failed to achieve statistical significance (95% CI 0.63-1.10). A sensitivity analysis that extended the surgical delay to >12 months yielded a survival hazard of 0.90 (95% CI 0.61-1.34). Tan said a post hoc power calculation showed the sample size was sufficient to detect a hazard ratio of 0.89.

Canadian Data

Shiff reported findings from an analysis of patients with renal masses ≥4 cm (≥cT1b) treated at Canadian centers during 2011 to 2019, which were included in the . He noted that a recommended a wait time of less than 28 days from imaging to surgery for patients with symptomatic renal tumors and for those with T1a, T2, or T3a N0M0 tumors. Patients with T1aN0M0 tumors could wait up to 90 days.

The analysis included 1,516 patients who had a median age of 62.1. The cohort consisted of 711 patients with T1b tumors, 426 with T2 tumors, and 377 with T3-4 tumors. Median time from final imaging to surgery decreased with tumor stage: 76, 42, and 33 days. Few patients with T2 (N=4) or T3-4 tumors (N=6) had surgery delays >24 weeks.

Multivariate analysis showed that RFS had significant associations with pathologic T stage (T1 vs T3-4, HR 0.36, P=0.033; T2 vs T3-4, NS), increasing tumor size (HR 1.10, P=0.0001 per one unit), and increasing tumor grade (2 vs 4, HR 0.50, P=0.001; 3 vs 4, HR 0.53, P<0.0001), but not surgical wait time.

For pathologic upstaging, the data yielded the curious finding of decreased likelihood for patients with delays of 13-24 weeks vs <4 weeks (HR 0.78, P=0.001). Shiff had no explanation for the finding. The risk of upstaging increased with tumor size (HR 1.10, P<0.0001) and grade (HR 0.17-0.78, P=0.009 to P<0.0001).

The multivariate analysis of OS showed that longer wait times increased the survival hazard only for patients with T3-4 tumors (13-24 vs <4 weeks, HR 4.21, P=0.006). Other significant influences on OS were Charlson score across all T stages and tumor size for T3-4 disease.

Acknowledging limitations of the data set, Shiff said the time from imaging to surgery was a surrogate for wait time. He added, "We do not know the reasons why certain patients experience prolonged surgical wait times, such as resource availability control of comorbidities, or other factors."