A morphology-based nephrometry score to predict pathological upstaging to T3 renal cell carcinoma

Abstract

Background: Patients with clinical T1-2 renal cell carcinoma (RCC) upstaging to pathological T3 showed worse survival prognosis than those without upstaging. We aimed to develop and validate a morphologybased nephrometry scoring system for predicting pathological upstaging to T3 of RCC. Methods:We retrospectively reviewed 200 patients with clinical T1-2 RCC who underwent surgical treatment. The nephrometry scores were measured through preoperative computed tomography images.The risk factors of pathological upstaging were identified by logistic regression models. The predictive accuracy of a novel morphology-based nephrometry scoring system (M-Index), was compared with R.E.N.A.L (radius, exophytic/endophytic, nearness, anterior/posterior, location), PADUA (preoperative aspects and dimensions used for an anatomic classification), DAP (diameter, axial, polar) and C-Index scores. Results:The upstaging rate of the population was 17% (34 out of 200 patients). The upstaging and non-upstaging groups were comparable in terms of age, gender ratio, body mass index, tumor laterality, and pathological type, while the upstaging group tended to have large tumor diameter, irregular tumor morphology, inner tumor location, and short polar and axial distance. Large tumor diameter refers to larger than 5 cm, while irregular tumor morphology refers to not regular shapes such as round, oval, or lobular. Univariate and multivariate logistic regression analyses showed that tumor morphology [odds ratio (OR)3.26, 95% confidence interval (CI): 1.79-5.97] and tumor rim location (OR 2.95, 95% CI: 1.16-7.46) were independent risk factors for pathological upstaging. The receiver operating characteristic curve and decision curve analysis (DCA) demonstrated the novel M-Index based on tumor morphology and rim location outperformed R.E.N.A.L, PADUA, DAP, and C-Index in the prediction of pathological upstaging (area under curve 0.756 vs. 0.728 vs. 0.641 vs. 0.661 vs. 0.743).Conclusions: Consisting of fewer non-complex parameters, the M-Index is an intuitive and practical tool with satisfactory predictive power for pathological upstaging to T3 in RCC patients undergoing surgery.

ctDNA predicts clinical T1a to pathological T3a upstaging after partial nephrectomy

“…5,32 Although the PADUA system can predict fat invasion to some extent, it is not sufficient to predict SFI or PFI. 37 As this system was originally designed for evaluating the surgical complexity and morbidity of PN, 13 the nephrometry system may be insufficient to predict SFI because tumor building into the renal sinus may not necessarily be a result of SFI. 37 The role of ctDNA has primarily been investigated in the monitoring of tumor progression during treatment because of the advantages of non-invasive ctDNA sampling methods.…”

“…Although the PADUA system can predict fat invasion to some extent, it is not sufficient to predict SFI or PFI 37 . As this system was originally designed for evaluating the surgical complexity and morbidity of PN, 13 the nephrometry system may be insufficient to predict SFI because tumor building into the renal sinus may not necessarily be a result of SFI 37 …”

“…The patients were stratified into two cohorts based on the presence of pT3a upstaging (upstaged vs. non‐upstaged). These two groups were compared to determine differences in preoperative factors previously identified for predicting pT3a upstaging 5,13,15 . The groups were specifically compared for differences in terms of patient age, sex, tumor size, PADUA nephrometry complexity, and presence of ctDNA.…”

“…In addition, although several studies have reported an association between high tumor complexity and pT3a upstaging rates, nephrometry systems have limitations in predicting pT3a upstaging. 13 Furthermore, among pT3a RCC, renal SFI has a significantly worse prognosis and more aggressive characteristics than PFI, 9,[16][17][18] as stated in the EAU guidelines. 19 However, previous studies have identified preoperative predictors of overall pT3a with SFI and PFI but did not consider the differences between them.…”

“…Among patients with cT1 ccRCC, a non‐negligible proportion have tumor upstaging to pT3a at final pathology, ranging from 4% to 9% of all cT1 tumors 7,8 . Although the prognosis of upstaging cT1–2 to pT3 seems controversial depending on the urological literature, 9–12 patients with cT1 RCC with pT3a upstaging have worse oncological outcomes 13,14 . Therefore, accurate prediction of clinically localized renal tumors for pathological upstaging to pT3a is an important issue in PN planning 13 .…”