External validation of a postoperative nomogram for the prediction of disease-specific survival in patients with papillary renal cell carcinoma using a large multicenter database

Development and External Validation of a Novel Nomogram Predicting Cancer-specific Mortality-free Survival in Surgically Treated Papillary Renal Cell Carcinoma Patients

BACKGROUND

Accurate prediction of cancer control outcomes in renal cell carcinoma (RCC) patients is important for counselling, follow-up planning, and selection of appropriate adjuvant trial designs.

OBJECTIVE

To develop and externally validate a novel contemporary population-based model for predicting cancer-specific mortality-free survival (CSM-FS) in surgically treated papillary RCC (papRCC) patients and to compare it with established risk categories (Leibovich 2018).

DESIGN, SETTING, AND PARTICIPANTS

Within the Surveillance, Epidemiology, and End Results database (2004-2019), we identified surgically treated papRCC patients (n = 3978). The population was randomly divided into development (50%, n = 1989) and external validation (50%, n = 1989) cohorts. Of the external validation cohort, 97% (n = 1930) of patients were included in a head-to-head comparison of the Leibovich 2018 risk categories addressing nonmetastatic patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Univariable Cox regression models tested the statistical significance in the prediction of CSM-FS. The most parsimonious model with the best validation metrics was selected as the multivariable nomogram. Accuracy, calibration, and decision curve analyses (DCAs) tested the Cox regression-based nomogram, as well as the Leibovich 2018 risk categories in the external validation cohort.

RESULTS AND LIMITATIONS

Age at diagnosis, grade, T stage, N stage, and M stage qualified for inclusion in the novel nomogram. In external validation, the accuracy of the novel nomogram was 0.83 at 5 yr and 0.80 at 10 yr. In nonmetastatic patients, 5- and 10-yr accuracy of the novel nomogram was 0.77 and 0.76, respectively. Conversely, 5- and 10-yr accuracy of the Leibovich 2018 risk categories was 0.70 and 0.66, respectively. The novel nomogram exhibited smaller departures from ideal predictions in calibration plots and higher net benefit in DCAs, when it was compared with the Leibovich 2018 risk categories. Limitations include the retrospective nature of the study, absence of a central pathological review, and inclusion of only North American patients.

CONCLUSIONS

The novel nomogram may represent a valuable clinical aid, when papRCC CSM-FS predictions are required.

PATIENT SUMMARY

We developed an accurate tool to predict death due to papillary kidney cancer in a North American population.

The first competing risk survival nomogram in patients with papillary renal cell carcinoma

There is still a lack of competing risk analysis of patients with papillary renal cell carcinoma (pRCC) following surgery. We performed the cumulative incidence function (CIF) to estimate the absolute risks of cancer-specific mortality (CSM) and other-cause mortality (OCM) of pRCC over time, and constructed a nomogram predicting the probability of 2-, 3- and 5-year CSM based on competing risk regression. A total of 5993 pRCC patients who underwent nephrectomy between 2010 and 2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The 2-, 3-, 5-year CSM rates were 3.2%, 4.4% and 6.5%, respectively, and that of OCM were 3.2%, 5.0% and 9.3%, respectively. The estimates of 5-year cumulative mortality were most pronounced among patients aged > 75 years in OCM (17.0%). On multivariable analyses, age, tumor grade, T stage, N stage, and with or without bone, liver and lung metastases were identified as independent predictors of CSM following surgery and were integrated to generate the nomogram. The nomogram achieved a satisfactory discrimination with the AUC_t of 0.730 at 5-year, and the calibration curves presented impressive agreements. Taken together, age-related OCM is a significant portion of all-cause mortality in elderly patients and our nomogram can be used for decision-making and patient counselling.

lncRNA 00312 Attenuates Cell Proliferation and Invasion and Promotes Apoptosis in Renal Cell Carcinoma via miR-34a-5p/ASS1 Axis

Background

Previous studies have demonstrated that lncRNAs play functional roles in regulating cancer cell proliferation, invasion, and apoptosis. Recent studies confirmed that lncRNA 00312 has important biological functions in lung and colorectal cancer. However, the role of lncRNA 00312 in renal cell carcinoma (RCC) remains unclear. Our aim was to explore the function of lncRNA 00312 in RCC and its potential molecular mechanism.

Methods

RCC cell lines A498 and ACHN were used as in vitro models in this study. RT-PCR was performed to determine lncRNA 00312, miR-34a-5p, and ASS1 mRNA expression. Proliferation and invasion were examined by CCK-8 and Transwell assay to confirm the function role of lncRNA 00312. Western blot analysis was used to examine the expression of apoptotic proteins Bax and Bcl-2.

Results

lncRNA was significantly downregulated in RCC cells such as A498 and ACHN; the expression of lncRNA 00312 in RCC tissues was significantly lower than that in adjacent normal tissues. Patients with low expression of lncRNA 00312 have worse prognosis regarding pathological grade, tumor size, and TNM stage. Overexpression of lncRNA 00312 suppressed A498 and ACHN cell proliferation and invasion, while promoting apoptosis. Our study found that miR-34a-5p had the potential binding site with lncRNA 00312 and revealed the role of miR-34a-5p in RCC. Furthermore, we confirmed that lncRNA 00312 played its role with the participation of ASS1 and miR-34a-5p.

Conclusion

lncRNA 00312 can inhibit RCC proliferation and invasion and promote apoptosis in vitro by suppressing miR-34a-5p and overexpressing ASS1. Our study demonstrated that the lncRNA 00312/miR-34a-5p/ASS1 axis may play a functional role in the progression of RCC; lncRNA 00312 abundance is a prognostic factor candidate for RCC survival, which provides new insights for RCC clinical treatment.in vitro models in this study. RT-PCR was performed to determine lncRNA 00312, miR-34a-5p, and ASS1 mRNA expression. Proliferation and invasion were examined by CCK-8 and Transwell assay to confirm the function role of lncRNA 00312. Western blot analysis was used to examine the expression of apoptotic proteins Bax and Bcl-2.