Clinical-Kidney cancer
Upstaging to pT3a disease in patients undergoing robotic partial nephrectomy for cT1 kidney cancer: Outcomes and predictors from a multi-institutional dataset

https://doi.org/10.1016/j.urolonc.2019.12.024Get rights and content

Highlights

  • Four % of cT1 renal masses were upstaged to pT3a.

  • Upstaged patients were more likely to present chronic kidney disease.

  • Upstaged tumors were more complex and associated to higher intraoperative complications.

  • Upstaged tumors presented worse 2-year recurrence-free survival.

  • Upstaging was an independent predictor of recurrence.

ABSTRACT

Objectives

Surgically treated clinical T1 (cT1) kidney cancer has in general a good prognosis, but there is a risk of upstaging that can potentially jeopardize the oncological outcomes after partial nephrectomy (PN). Aim of this study is to analyze the outcomes of robot-assisted PN (RAPN) for cT1 kidney cancer upstaged to pT3a, and to identify predictors of upstaging.

Material and methods

The study cohort included 1,640 cT1 patients who underwent RAPN between 2005 and 2018 at 10 academic institutions. Multivariate logistic regression model was used to assess the predictors of upstaging. Kaplan-Meier curves and multivariable Cox regression analyses were used to evaluate recurrence-free survival and overall survival.

Results

Overall, 74 (4%) were upstaged cases (cT1/pT3a). Upstaged patients presented larger renal tumors (3.1 vs. 2.4 cm; P = 0.001), and higher R.E.N.A.L. score (8.0 vs. 6.0; P = 0.004). cT1/pT3a group had higher rate of intraoperative complications (5 vs. 1% P = 0.032), higher pathological tumor size (3.2 vs. 2.5 cm; P < 0.001), higher rate of Fuhrman grade ≥3 (32 vs. 17%; P = 0.002), and higher number of sarcomatoid differentiation (4 vs. 1%; P = 0.008). Chronic kidney disease (CKD) stage ≥3 (OR: 2.54; P < 0.014), and clinical tumor size (OR: 1.07; P < 0.001) were independent predictors of upstaging. cT1/pT3a group had worse 2-year (94% vs. 99%) recurrence-free survival (P < 0.001).

Conclusions

Upstaging to pT3a in patients with cT1 renal mass undergoing RAPN represents an uncommon event, involving less than 5% of cases. Pathologic upstaging might translate into worse oncological outcomes, and therefore strict follow-up protocols should be applied in these cases.

Introduction

The exponential increase in early detection of kidney cancer has dramatically changed its management over the past 2 decades, and partial nephrectomy (PN) has replaced radical nephrectomy as standard surgical treatment for T1 disease [1,2]. A paradigm shift towards PN was also observed in the management of T1b and T2 renal masses [3], [4], [5]. Robotic-assisted PN (RAPN) is rapidly emerging as preferred surgical approach for PN, given its potential benefits [6]. Other less invasive treatment options, such as active surveillance and kidney ablation, can be adopted for selected cases.

While surgically treated clinical T1 (cT1) kidney cancer has in general a good prognosis, there is a risk of upstaging that can potentially jeopardize the oncological outcomes of patients undergoing PN [7]. It is commonly accepted to consider “upstaged” those cT1 tumors which result as pT3a at final pathology. This because the upstaging to pT2 or pT3b could be consequence of the radiologist misjudgment of the tumor dimension or of the presence of venous thrombus [8].

Which could be the predictors as well as the impact of the upstaging on the prognosis remains unclear. The aim of the current study was to provide further evidence regarding the predictors, and the prognostic value of the upstaging to pT3a relying on one of the largest cohorts of cT1 patients who underwent RAPN at 10 high volume centers.

Section snippets

Study population

This is a retrospective international study including data of RAPN performed at 10 academic Institutions (6 European and 4 USA). Institutional review board approval and data sharing was obtained at each center involved. Data of 1,641 patients who underwent RAPN between 2005 and 2018 were collected. Among these, 74 (4%) were upstaged cases (cT1/pT3a), and they were retrospectively compared to 1,566 patients whose preoperative staging was confirmed at pathological final report (cT1/pT1).

Variable definition

Baseline

Results

Overall, 74 (4%) patients were upstaged at final histopathology (cT1/pT3a). At baseline cT1/pT3a group presented higher rate of CKD stage ≥3 (20 vs. 7%; P = 0.001), larger renal tumors (median size 4.3 vs. 2.7 cm; P < 0.001), and higher R.E.N.A.L. score (median 8 vs. 6; P = 0.004; Table 1) relative to cT1/pT1 group.

No statistically significant difference was observed in terms of operative time, and estimated blood loss, whereas cT1/pT3a group had longer median ischemia time (20 vs. 16 minutes; P

Discussion

This is a comparative analysis between non-upstaged (cT1/pT1) and upstaged (cT1/pT3a) patients after RAPN. Our results showed that only 4% of cT1 renal masses were upstaged to pT3a. We underlined some differences among the two groups which could be useful to identify preoperatively those patients who might conceal a pT3a tumor, who could require a different surgical and follow-up management.

The correlation between parenchymal renal tumor and CKD is wellestablished as neoplastic masses

Conclusions

Upstaging to pT3a in patients with cT1 renal mass undergoing RAPN represents an uncommon event, involving less than 5% of cases. One should be aware that pathologic upstaging might translate into worse oncological outcomes, and therefore strict follow-up protocols should be applied in these cases. Preoperative identification of these cases remains challenging, and it needs further investigation.

Conflict of interest

The authors declare that they have no conflicts of interest.

References (25)

Cited by (16)

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Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Dr. Veccia is an Italian Society of Urology-American Urological Association (SIU-AUA) research fellow. Funding for his fellowship is also provided by the VCU Urology Research Fund.

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