Development and validation of a multicenter Cox regression model to predict all-cause mortality in patients with renal masses suspicious for renal cancer

OBJECTIVE

Life expectancy models are useful tools to support clinical decision-making. Prior models have not been used widely in clinical practice for patients with renal masses. We sought to develop and validate a model to predict life expectancy following the detection of a localized renal mass suspicious for renal cell carcinoma.

MATERIALS AND METHODS

Using retrospective data from 2 large centers, we identified patients diagnosed with clinically localized renal parenchymal masses from 1998 to 2018. After 2:1 random sampling into a derivation and validation cohort stratified by site, we used age, sex, log-transformed tumor size, simplified cardiovascular index and planned treatment to fit a Cox regression model to predict all-cause mortality from the time of diagnosis. The model's discrimination was evaluated using a C-statistic, and calibration was evaluated visually at 1, 5, and 10 years.

RESULTS

We identified 2,667 patients (1,386 at Corewell Health and 1,281 at Johns Hopkins) with renal masses. Of these, 420 (16%) died with a median follow-up of 5.2 years (interquartile range 2.2-8.3). Statistically significant predictors in the multivariable Cox regression model were age (hazard ratio [HR] 1.04; 95% confidence interval [CI] 1.03-1.05); male sex (HR 1.40; 95% CI 1.08-1.81); log-transformed tumor size (HR 1.71; 95% CI 1.30-2.24); cardiovascular index (HR 1.48; 95% CI 1.32-1.67), and planned treatment (HR: 0.10, 95% CI: 0.06-0.18 for kidney-sparing intervention and HR: 0.20, 95% CI: 0.11-0.35 for radical nephrectomy vs. no intervention). The model achieved a C-statistic of 0.74 in the derivation cohort and 0.73 in the validation cohort. The model was well-calibrated at 1, 5, and 10 years of follow-up.

CONCLUSIONS

For patients with localized renal masses, accurate determination of life expectancy is essential for decision-making regarding intervention vs. active surveillance as a primary treatment modality. We have made available a simple tool for this purpose.

Simplified cardiovascular index may be the best comorbidity index for clinical use in prediction of mortality for renal cancer patients

OBJECTIVE

Understanding the relationship between comorbidities and life expectancy is important in cancer patients who carry risks of cancer and noncancer-related mortality. Comorbidity indices (CI) are tools to provide an objective measure of competing risks of death. We sought to determine which CI might be best incorporated into clinical practice for patients with suspected renal cancer.

MATERIALS AND METHODS

1572 patients diagnosed with renal masses (stage I-IV) between 1998 and 2016 were analyzed for this study. Patient data were gathered from a community-based health center. Comorbidities were evaluated individually, and with 1 of 4 CI: Charlson (CCI), updated CCI (uCCI), age-adjusted CCI (aCCI), and simplified cardiovascular index (CVI). Cox-proportional hazard analysis of all-cause mortality was performed using the four CI, adjusting for the 4 CI, adjusting for age, gender, race, tumor size, and tumor stage.

RESULTS

Univariable analyses revealed the four CI were significant predictors of mortality (P < 0.05), as were age, gender, tumor size, and stage. Comorbid conditions at diagnosis included hypertension (47.8%), diabetes mellitus (47.2%), coronary artery disease (41.1%), chronic kidney disease (31.8%), peripheral vascular disease (8.0%), congestive heart failure (5.7%), chronic obstructive pulmonary disease (5.7%), and cerebrovascular disease (2.0%). When analyzing the 4 CI in multivariable survival analyses accounting for factors available at diagnosis, and analyses incorporating pathologic and recurrence data, only CVI score and uCCI remained statistically significant (P < 0.05). Limitations of this work are the retrospective nature of data collection and data from a single institution, limiting the generalizability.

CONCLUSION

Increasing comorbidity, age, tumor size, and cM stage are predictors of ACM for suspected renal cancer patients. CVI appears to provide comparable information to various iterations of CCI (uCCI, aCCI) while being the simplest to use. Utilization of CVI may assist clinicians and patients when considering between interventional and noninterventional approaches for suspected renal cancer.

A Statewide Quality Improvement Collaborative's Adherence to the 2017 American Urological Association Guidelines Regarding Initial Evaluation of Patients With Clinical T1 Renal Masses

OBJECTIVE

To evaluate MUSIC-KIDNEY's adherence to the American Urological Association (AUA) guidelines regarding the initial evaluation of patient's with clinical T1 (cT1) renal masses.

METHODS

We reviewed MUSIC-KIDNEY registry data for patients with newly diagnosed cT1 renal masses to assess for adherence with the 2017 AUA guideline statements regarding recommendations to obtain (1) CMP, (2) CBC, (3) UA, (4) abdominal cross-sectional imaging, and (5) chest imaging. An evaluation consisting of all 5 guideline measures was considered "complete compliance." Variation with guideline adherence was assessed by contributing practice, management strategy, and renal mass size.

RESULTS

We identified 1808 patients with cT1 renal masses in the MUSIC-KIDNEY registry, of which 30% met the definition of complete compliance. Most patients received care that was compliant with recommendations to obtain laboratory testing with 1448 (80%), 1545 (85%), and 1472 (81%) patients obtaining a CMP, CBC, and UA respectively. Only 862 (48%) patients underwent chest imaging. Significant variation exists in complete guideline compliance for contributing practices, ranging from 0% to 45% as well as for patients which underwent immediate intervention compared with initial observation (37% vs 23%) and patients with cT1b masses compared with cT1a masses (36% vs 28%).

CONCLUSION

Complete guideline compliance in the initial evaluation of patients with cT1 renal masses is poor, which is mainly driven by omission of chest imaging. Significant variation in guideline adherence is seen across practices, as well as patients undergoing an intervention vs observation, and cT1a vs cT1b masses. There are ample quality improvement opportunities to increase adherence and decrease variability with guideline recommendations.

Limitations of abdominopelvic CT and multiparametric MR imaging for detection of lymph node metastases prior to radical prostatectomy

PURPOSE

To investigate the performance of pre-surgery CT and multiparametric MRI (mpMRI) to identify lymph node (LN) metastases in the Michigan Urological Surgery Improvement Collaborative (MUSIC). Abdominopelvic CT and mpMRI are commonly used for intermediate- and high-risk prostate cancer (PCa) staging.

METHODS

Retrospective analysis of the MUSIC registry identified patients undergoing robot-assisted radical prostatectomy (RP) between 3/2012 and 7/2018. Patients were classified according to pre-surgery imaging modality. Primary outcomes were operating characteristics of CT and mpMRI for detection of pathologic LN involvement (pN1).

RESULTS

A total of 10,250 patients underwent RP and 3924 patients (38.3%) underwent CT and/or mpMRI prior to surgery. Suspicion for LN involvement was identified on 2.3% CT and 1.9% mpMRI. Overall, 391 patients were pN1(3.8%), including 0.1% low-, 2.1% intermediate-, and 10.9% high-risk PCa patients. Of 235 pN1 patients that underwent CT prior, far more had negative (91.1%) than positive (8.9%) findings, yielding sensitivity: 8.9%, specificity: 98.3%, negative predictive value (NPV): 92.1%, and positive predictive value (PPV): 32.3% for CT with regard to LN metastases. Similarly, more patients with pN1 disease had negative mpMRI (81.0%) then suspicious or indeterminate MRI (19.0%), yielding sensitivity: 19.0%, specificity: 97.3%, NPV: 95.9%, and PPV: 26.7%.

CONCLUSIONS

Abdominopelvic CT and mpMRI have clear limitations in identifying LN metastases. Additional clinicopathologic features should be considered when making management decisions, as 2.1% and 10.9% with intermediate-and high-risk cancer had metastatic LNs. The majority of pN1 patients had a negative CT or a negative/indeterminate mpMRI prior to RP. Pelvic LN dissection should be performed in RP patients with intermediate- or high-risk PCa, independent of preoperative imaging results.