The establishment of KORCC (KOrean Renal Cell Carcinoma) database

Machine learning models for predicting the onset of chronic kidney disease after surgery in patients with renal cell carcinoma

BACKGROUND

Patients with renal cell carcinoma (RCC) have an elevated risk of chronic kidney disease (CKD) following nephrectomy. Therefore, continuous monitoring and subsequent interventions are necessary. It is recommended to evaluate renal function postoperatively. Therefore, a tool to predict CKD onset is essential for postoperative follow-up and management.

METHODS

We constructed a cohort using data from eight tertiary hospitals from the Korean Renal Cell Carcinoma (KORCC) database. A dataset of 4389 patients with RCC was constructed for analysis from the collected data. Nine machine learning (ML) models were used to classify the occurrence and nonoccurrence of CKD after surgery. The final model was selected based on the area under the receiver operating characteristic (AUROC), and the importance of the variables constituting the model was confirmed using the shapley additive explanation (SHAP) value and Kaplan-Meier survival analyses.

RESULTS

The gradient boost algorithm was the most effective among the various ML models tested. The gradient boost model demonstrated superior performance with an AUROC of 0.826. The SHAP value confirmed that preoperative eGFR, albumin level, and tumor size had a significant impact on the occurrence of CKD after surgery.

CONCLUSIONS

We developed a model to predict CKD onset after surgery in patients with RCC. This predictive model is a quantitative approach to evaluate post-surgical CKD risk in patients with RCC, facilitating improved prognosis through personalized postoperative care.

Retrospective Multicenter Analysis of Prognostic Risk Factors for One Year Recurrence in Patient With Renal Cell Carcinoma After Partial or Radical Nephrectomy: Results of Korean Renal Cancer Study Group (KRoCS) Database

BACKGROUND

We sought to identify prognostic risk factors for one year recurrence in patient with renal cell carcinoma (RCC) after partial or radical nephrectomy.

METHODS

We performed a retrospective study of 1,269 patients with RCC after partial or radical nephrectomy and diagnosed recurrence using Korean Renal Cancer Study Group (KRoCS) database between January 1991 and March 2017. Recurrence-free survival (RFS), and overall survival (OS) were calculated using the Kaplan-Meier method and multivariate Cox regression analysis were performed to evaluate independent prognostic factors for recurrence.

RESULTS

The median patient age was 56 years and median follow-up period was 67 months. Multivariable analysis demonstrated BMI greater than or equal to 23 and less than 30 (vs. BMI less than 23, hazard ratio [HR]: 0.707, P = 0.020) reduced recurrence one year postoperatively. Eastern Cooperative Oncology Group performance status (ECOG PS) greater than or equal to 1 (vs. ECOG PS 0, HR: 1.548, P = 0.007), high pathological T stage (pT2 vs. pT1, HR: 2.622, P < 0.001; pT3 vs. pT1, HR: 4.256, P < 0.001; pT4 vs. pT1, HR: 4.558, P < 0.001), and tumor necrosis (vs. no tumor necrosis, HR: 2.822, P < 0.001) were independent predictive factors for early recurrence within one year in patients with RCC. Statistically significant differences on RFS and OS were found among pathological T stages (pT2 vs. pT1; pT3 vs. pT1; pT4 vs. pT1, all P < 0.001).

CONCLUSION

This large multicenter study demonstrated ECOG PS greater than or equal to 1, high pathological T stage, tumor necrosis and BMI less than 23 were significant prognostic risk factors of early recurrence within one year in patients with RCC who underwent nephrectomy.

Machine learning based prediction for oncologic outcomes of renal cell carcinoma after surgery using Korean Renal Cell Carcinoma (KORCC) database

We developed a novel prediction model for recurrence and survival in patients with localized renal cell carcinoma (RCC) after surgery and a novel statistical method of machine learning (ML) to improve accuracy in predicting outcomes using a large Asian nationwide dataset, updated KOrean Renal Cell Carcinoma (KORCC) database that covered data for a total of 10,068 patients who had received surgery for RCC. After data pre-processing, feature selection was performed with an elastic net. Nine variables for recurrence and 13 variables for survival were extracted from 206 variables. Synthetic minority oversampling technique (SMOTE) was used for the training data set to solve the imbalance problem. We applied the most of existing ML algorithms introduced so far to evaluate the performance. We also performed subgroup analysis according to the histologic type. Diagnostic performances of all prediction models achieved high accuracy (range, 0.77-0.94) and F1-score (range, 0.77-0.97) in all tested metrics. In an external validation set, high accuracy and F1-score were well maintained in both recurrence and survival. In subgroup analysis of both clear and non-clear cell type RCC group, we also found a good prediction performance.

Projection of Cancer Incidence and Mortality From 2020 to 2035 in the Korean Population Aged 20 Years and Older

OBJECTIVES

This study aimed to identify the current patterns of cancer incidence and estimate the projected cancer incidence and mortality between 2020 and 2035 in Korea.

METHODS

Data on cancer incidence cases were extracted from the Korean Statistical Information Service from 2000 to 2017, and data on cancer-related deaths were extracted from the National Cancer Center from 2000 to 2018. Cancer cases and deaths were classified according to the International Classification of Diseases, 10th edition. For the current patterns of cancer incidence, age-standardized incidence rates (ASIRs) and age-standardized mortality rates were investigated using the 2000 mid-year estimated population aged over 20 years and older. A joinpoint regression model was used to determine the 2020 to 2035 trends in cancer.

RESULTS

Overall, cancer cases were predicted to increase from 265 299 in 2020 to 474 085 in 2035 (growth rate: 1.8%). The greatest increase in the ASIR was projected for prostate cancer among male (7.84 vs. 189.53 per 100 000 people) and breast cancer among female (34.17 vs. 238.45 per 100 000 people) from 2000 to 2035. Overall cancer deaths were projected to increase from 81 717 in 2020 to 95 845 in 2035 (average annual growth rate: 1.2%). Although most cancer mortality rates were projected to decrease, those of breast, pancreatic, and ovarian cancer among female were projected to increase until 2035.

CONCLUSIONS

These up-to-date projections of cancer incidence and mortality in the Korean population may be a significant resource for implementing cancer-related regulations or developing cancer treatments.

Machine learning-based prediction model for late recurrence after surgery in patients with renal cell carcinoma

Background

Renal cell carcinoma is characterized by a late recurrence that occurs 5 years after surgery; hence, continuous monitoring and follow-up is necessary. Prognosis of late recurrence of renal cell carcinoma can only be improved if it is detected early and treated appropriately. Therefore, tools for rapid and accurate renal cell carcinoma prediction are essential.

Methods

This study aimed to develop a prediction model for late recurrence after surgery in patients with renal cell carcinoma that can be used as a clinical decision support system for the early detection of late recurrence. We used the KOrean Renal Cell Carcinoma database that contains large-scale cohort data of patients with renal cell carcinoma in Korea. From the collected data, we constructed a dataset of 2956 patients for the analysis. Late recurrence and non-recurrence were classified by applying eight machine learning models, and model performance was evaluated using the area under the receiver operating characteristic curve.

Results

Of the eight models, the AdaBoost model showed the highest performance. The developed algorithm showed a sensitivity of 0.673, specificity of 0.807, accuracy of 0.799, area under the receiver operating characteristic curve of 0.740, and F1-score of 0.609.

Conclusions

To the best of our knowledge, we developed the first algorithm to predict the probability of a late recurrence 5 years after surgery. This algorithm may be used by clinicians to identify patients at high risk of late recurrence that require long-term follow-up and to establish patient-specific treatment strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01964-w.

Identification of Survival-Specific Genes in Clear Cell Renal Cell Carcinoma Using a Customized Next-Generation Sequencing Gene Panel

Purpose: Although mutations are associated with carcinogenesis, little is known about survival-specific genes in clear cell renal cell carcinoma (ccRCC). We developed a customized next-generation sequencing (NGS) gene panel with 156 genes. The purpose of this study was to investigate whether the survival-specific genes we found were present in Korean ccRCC patients, and their association with clinicopathological findings. Materials and Methods: DNA was extracted from the formalin-fixed, paraffin-embedded tissue of 22 ccRCC patients. NGS was performed using our survival-specific gene panel with an Illumina MiSeq. We analyzed NGS data and the correlations between mutations and clinicopathological findings and also compared them with data from the Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) and Renal Cell Cancer-European Union (RECA-EU). Results: We found a total of 100 mutations in 37 of the 156 genes (23.7%) in 22 ccRCC patients. Of the 37 mutated genes, 11 were identified as clinicopathologically significant. Six were novel survival-specific genes (ADAMTS10, CARD6, NLRP2, OBSCN, SECISBP2L, and USP40), and five were top-ranked mutated genes (AKAP9, ARID1A, BAP1, KDM5C, and SETD2). Only CARD6 was validated as an overall survival-specific gene in this Korean study (p = 0.04, r = −0.441), TCGA-KIRC cohort (p = 0.0003), RECA-EU (p = 0.0005). The 10 remaining gene mutations were associated with clinicopathological findings; disease-free survival, mortality, nuclear grade, sarcomatoid component, N-stage, sex, and tumor size. Conclusions: We discovered 11 survival-specific genes in ccRCC using data from TCGA-KIRC, RECA-EU, and Korean patients. We are the first to find a correlation between CARD6 and overall survival in ccRCC. The 11 genes, including CARD6, NLRP2, OBSCN, and USP40, could be useful diagnostic, prognostic, and therapeutic markers in ccRCC.

A Retrospective, Multicenter, Long-Term Follow-Up Analysis of the Prognostic Characteristics of Recurring Non-Metastatic Renal Cell Carcinoma After Partial or Radical Nephrectomy

This study aimed to compare the cancer-specific survival (CSS) and overall survival (OS) of nephrectomized patients with non-metastatic renal cell carcinoma (nmRCC) and local recurrence without distant metastasis (LR group), those with metastasis without local recurrence (MET group), and those with both local recurrence and metastasis (BOTH group). This retrospective multicenter study included 464 curatively nephrectomized patients with nmRCC and disease recurrence between 2000 and 2012; the follow-up period was until 2017. After adjusting for significant clinicopathological factors using Cox proportional hazard models, CSS and OS were compared between the MET (n = 50, 10.7%), BOTH (n = 95, 20.5%), and LR (n = 319, 68.8%) groups. The CSS and OS rates were 34.7 and 6.5% after a median follow-up of 43.9 months, respectively. After adjusting for significant prognostic factors of OS and CSS, the MET group had hazard ratios (HRs) of 0.51 and 0.57 for OS and CSS (p = 0.039 and 0.103), respectively, whereas the BOTH group had HRs of 0.51 and 0.60 for OS and CSS (p < 0.05), respectively; LR was taken as a reference. The 2-year OS and CSS rates from the date of nephrectomy and disease recurrence were 86.9% and 88.9% and 63.5% and 67.8%, respectively, for the LR group; 89.5% and 89.5% and 48.06% and 52.43%, respectively, for the MET group; and 96.8% and 96.8% and 86.6% and 82.6%, respectively, for the BOTH group. Only the LR and BOTH groups had significant differences in the 2-year OS and CSS rates (p < 0.05). In conclusion, our study showed that the LR group had worse survival prognoses than any other group in nephrectomized patients with nmRCC.

Machine Learning Approach to Predict the Probability of Recurrence of Renal Cell Carcinoma After Surgery: Prediction Model Development Study

Background

Renal cell carcinoma (RCC) has a high recurrence rate of 20% to 30% after nephrectomy for clinically localized disease, and more than 40% of patients eventually die of the disease, making regular monitoring and constant management of utmost importance.

Objective

The objective of this study was to develop an algorithm that predicts the probability of recurrence of RCC within 5 and 10 years of surgery.

Methods

Data from 6849 Korean patients with RCC were collected from eight tertiary care hospitals listed in the KOrean Renal Cell Carcinoma (KORCC) web-based database. To predict RCC recurrence, analytical data from 2814 patients were extracted from the database. Eight machine learning algorithms were used to predict the probability of RCC recurrence, and the results were compared.

Results

Within 5 years of surgery, the highest area under the receiver operating characteristic curve (AUROC) was obtained from the naïve Bayes (NB) model, with a value of 0.836. Within 10 years of surgery, the highest AUROC was obtained from the NB model, with a value of 0.784.

Conclusions

An algorithm was developed that predicts the probability of RCC recurrence within 5 and 10 years using the KORCC database, a large-scale RCC cohort in Korea. It is expected that the developed algorithm will help clinicians manage prognosis and establish customized treatment strategies for patients with RCC after surgery.

Prognostic significance of pathologic nodal positivity in non-metastatic patients with renal cell carcinoma who underwent radical or partial nephrectomy

This retrospective, five-multicenter study was aimed to evaluate the prognostic impact of pathologic nodal positivity on recurrence-free (RFS), metastasis-free (MFS), overall (OS), and cancer-specific (CSS) survivals in patients with non-metastatic renal cell carcinoma (nmRCC) who underwent either radical or partial nephrectomy with/without LN dissection. A total of 4236 nmRCC patients was enrolled between 2000 and 2012, and followed up through the end of 2017. Survival measures were compared between 52 (1.2%) stage pT1-4N1 (LN+) patients and 4184 (98.8%) stage pT1-4N0 (LN-) patients using Kaplan-Meier analysis with the log-rank test and Cox regression analysis to determine the prognostic risk factors for each survival measure. During the median 43.8-month follow-up, 410 (9.7%) recurrences, 141 (3.3%) metastases, and 351 (8.3%) deaths, including 212 (5.0%) cancer-specific deaths, were reported. The risk factor analyses showed that predictive factors for RFS, CSS, and OS were similar, whereas those of MFS were not. After adjusting for significant clinical factors affecting survival outcomes considering the hazard ratios (HR) of each group, the LN+ group, even those with low pT stage, had similar to or worse survival outcomes than the pT3N0 (LN-) group in multivariable analysis and had significantly more relationship with RFS than MFS. All survival measures were significantly worse in pT1-2N1 patients (MFS/RFS/OS/CSS; HR 4.12/HR 3.19/HR 4.41/HR 7.22) than in pT3-4N0 patients (HR 3.08/HR 2.92/HR 2.09/HR 3.73). Therefore, LN+ had an impact on survival outcomes worse than pT3-4N0 and significantly affected local recurrence rather than distant metastasis compared to LN- in nmRCC after radical or partial nephrectomy.

Deep learning based prediction of prognosis in nonmetastatic clear cell renal cell carcinoma

Survival analyses for malignancies, including renal cell carcinoma (RCC), have primarily been conducted using the Cox proportional hazards (CPH) model. We compared the random survival forest (RSF) and DeepSurv models with the CPH model to predict recurrence-free survival (RFS) and cancer-specific survival (CSS) in non-metastatic clear cell RCC (nm-cRCC) patients. Our cohort included 2139 nm-cRCC patients who underwent curative-intent surgery at six Korean institutions between 2000 and 2014. The data of two largest hospitals’ patients were assigned into the training and validation dataset, and the data of the remaining hospitals were assigned into the external validation dataset. The performance of the RSF and DeepSurv models was compared with that of CPH using Harrel’s C-index. During the follow-up, recurrence and cancer-specific deaths were recorded in 190 (12.7%) and 108 (7.0%) patients, respectively, in the training-dataset. Harrel’s C-indices for RFS in the test-dataset were 0.794, 0.789, and 0.802 for CPH, RSF, and DeepSurv, respectively. Harrel’s C-indices for CSS in the test-dataset were 0.831, 0.790, and 0.834 for CPH, RSF, and DeepSurv, respectively. In predicting RFS and CSS in nm-cRCC patients, the performance of DeepSurv was superior to that of CPH and RSF. In no distant time, deep learning-based survival predictions may be useful in RCC patients.

The effect of the papillary renal cell carcinoma subtype on oncological outcomes

The study aimed to compare the clinicopathological features and prognosis between type I and type II papillary renal cell carcinoma (PRCC) and to investigate whether the subtypes of PRCC would affect oncological outcomes. A total of 102 patients with PRCC were recruited, of which 42 were type I PRCC and 60 type II. The clinicopathological features and oncologic outcomes of the patients were evaluated. The type II cases had a higher WHO/ISUP grading (P < 0.001), T (P = 0.003), N (P = 0.010) stage and stage grouping (P = 0.011) than the type I. During a median follow-up period of 61.4 months, 1-year cancer specific survival (CSS) of the type I was 100%, 5-year CSS was 95.2%, the 1-year CSS of the type II was 96.2%, and 5-year CSS was 75.7%. The univariate analysis showed that subtype, symptoms, TNM, stage grouping, WHO/ISUP grading and surgical methods appeared to affect prognosis of the patients with PRCC. However, multivariate analysis revealed that only stage grouping was the independent risk factor. After the stage grouping factor was adjusted for the analysis, there were no statistically significant differences in CSS (P = 0.214) and PFS (P = 0.190) between the localized type I and type II PRCC groups. Compared with type I PRCC, type II had higher pathological T, N stage and WHO/ISUP grading. However, it was the Stage grouping that made a great difference to oncological outcomes, rather than the subtype of PRCC.

The prognostic role of preoperative serum albumin/globulin ratio in patients with non-metastatic renal cell carcinoma undergoing partial or radical nephrectomy

This multi-institutional study sought to clarify the association between the preoperative serum albumin/globulin ratio (AGR) and the prognosis of renal cell carcinoma (RCC) in a large cohort. This study encompassed eight institutions and 2,970 non-metastatic RCC patients who underwent a radical or partial nephrectomy from the Korean RCC (KORCC) database. A low AGR (1,143 patients; 38.5%) was defined as a preoperative AGR of less than 1.47 and a high AGR (1,827 patients; 61.5%) was defined as that 1.47 or greater. In the low AGR group, older age, female gender, the incidence of symptom presentation when diagnosed, diabetes, and hypertension was higher than in the high AGR group. Patients with low AGRs showed more progressive tumor stages with higher Fuhrman nuclear grades (all P-values < 0.05). Patients in the low AGR group had a significantly lower overall survival rate (OS) and recurrence-free survival rate (RFS) in the Kaplan-Meier curves (all P-values < 0.05). AGR was an independent prognostic factor for predicting the OS and RFS in the multivariate analysis (all P-values < 0.05). The preoperative AGR is approachable and economical to use clinically for estimating the prognosis of RCC patients treated with surgery.

Cutaneous metastatic renal cell carcinoma to the scalp

Renal cell carcinoma (RCC) represents 2% to 3% of human cancers and is aggressive, with metastatic capability. The frequent metastatic sites are lung, bone, and liver. Reports of RCC metastatic to skin, and especially scalp are rare. Here we present an 83-year-old woman who was diagnosed with RCC 19 years prior and had a metastatic scalp lesion. An 83-year-old woman presented with a red-to-purple, protruding lesion at the right parietotemporal area. Twenty-three years ago, a right renal mass was incidentally discovered on ultrasound through a routine medical examination. She underwent right nephrectomy for RCC 4 years later. Five months after nephrectomy, new lung nodules were observed. Fifteen years after nephrectomy, metastatic lesions were found in the pelvic bone. She visited dermatology department for evaluation of the new scalp lesion, a year before she first visited our department. Despite chemotherapy, the mass was gradually enlarged. She consulted the plastic surgery department for management of the metastatic RCC was successfully treated with total excision including a 1-cm safety margin, local flap, and STSG coverage. Complete healing was observed, without evidence of recurrence during a 7-month followup. Metastases to the skin are rare, but must be kept in mind because of its high metastatic ability and poor prognosis.

Retrospective Multicenter Long-Term Follow-up Analysis of Prognostic Risk Factors for Recurrence-Free, Metastasis-Free, Cancer-Specific, and Overall Survival After Curative Nephrectomy in Non-metastatic Renal Cell Carcinoma

We evaluated prognostic risk factors of recurrence-free survival (RFS), metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS) outcomes in patients with non-metastatic renal cell carcinoma (nmRCC) after curative nephrectomy during long-term follow-up. The medical records of 4,260 patients with nmRCC who underwent curative nephrectomy between 2000 and 2012 from five Korean institutions and follow-up after postoperative 1 month until December 2017 were retrospectively analyzed for RFS, MFS, OS, and CSS. During the median 43.86 months of follow-up, 342 recurrences, 127 metastases, and 361 deaths, including 222 cancer-specific deaths, were reported. In addition to the unreached median survival of RFS and MFS, the median OS and CSS times were 176.75 and 227.47 months, respectively. Multivariable analyses showed that nephrectomy type (laparoscopy vs. open), pathological T stages, and nuclear grade were common significant risk factors for survival, and the baseline ASA, hemoglobin, and pathological N stage were common factors only for RFS, OS, and CSS (p < 0.05). Further, tumor necrosis for MFS; platelet count, extent (partial vs. radical) of surgery, and lymphovascular invasion for RFS; baseline diabetes, hypertension, age, body mass index, extent of surgery, and pathological sarcomatoid differentiation for OS; and baseline diabetes, hypertension, body mass index, and pathological sarcomatoid differentiation for CSS were additionally significant risk factors (p < 0.05). RFS, MFS, OS, and CSS were significantly different depending on the pathological T stages (p < 0.05). In conclusion, this large-numbered, long-term follow-up study revealed significant factors affecting the survival of patients with nephrectomized nmRCC.

The Korea Cancer Big Data Platform (K-CBP) for Cancer Research

Data warehousing is the most important technology to address recent advances in precision medicine. However, a generic clinical data warehouse does not address unstructured and insufficient data. In precision medicine, it is essential to develop a platform that can collect and utilize data. Data were collected from electronic medical records, genomic sequences, tumor biopsy specimens, and national cancer control initiative databases in the National Cancer Center (NCC), Korea. Data were de-identified and stored in a safe and independent space. Unstructured clinical data were standardized and incorporated into cancer registries and linked to cancer genome sequences and tumor biopsy specimens. Finally, national cancer control initiative data from the public domain were independently organized and linked to cancer registries. We constructed a system for integrating and providing various cancer data called the Korea Cancer Big Data Platform (K-CBP). Although the K-CBP could be used for cancer research, the legal and regulatory aspects of data distribution and usage need to be addressed first. Nonetheless, the system will continue collecting data from cancer-related resources that will hopefully facilitate precision-based research.

A Low Geriatric Nutritional Risk Index is Associated with Aggressive Pathologic Characteristics and Poor Survival after Nephrectomy in Clear Renal Cell Carcinoma: A Multicenter Retrospective Study

Purpose: To investigated the prognostic significance of the geriatric nutritional risk index (GNRI) in patients with surgically treated clear cell renal cell carcinoma (ccRCC).Patients and methods: We retrospectively selected 4,591 consecutive patients with surgically treated ccRCC from a multi-institutional Korean collaboration between 1988 and 2015. The clinical significance of the GNRI as a continuous and categorical variable was determined.Results: Preoperative low GNRI was significantly associated with older age, low body mass index, presence of diabetes, poor performance status, and presence of symptoms at diagnosis, as well as pathologic features such as aggressive tumor characteristics including large tumor size, advanced stage, high nuclear grade, lymphovascular invasion, sarcomatous differentiation, and tumor necrosis. A low GNRI was significantly associated with a short recurrence-free survival (RFS) in localized (pT1-2N0M0) ccRCC and cancer-specific survival (CSS) in the entire cohort, and with short RFS and CSS in the subgroup analysis according to age categories (≤65 and >65 years). Multivariate Cox regression analysis showed that preoperative GNRI, as a continuous or categorical variable, was an independent predictor of RFS and CSS.Conclusion: Malnutrition as assessed by the preoperative GNRI is associated with aggressive tumor characteristics and poor survival in patients with surgically treated ccRCC.

Trends in clinical, operative, and pathologic characteristics of surgically treated renal mass in a Korean center: A surgical series from 1988 through 2015

Purpose

To analyze trends over a period of 28 years in the clinical, operative, and pathologic characteristics of patients with a renal mass who underwent surgical resection in Korea.

Materials and Methods

Consecutive patients (n=6,231) with a renal mass who underwent surgical resection at eight Korean institutions between 1988 and 2015 were reviewed. Patients were assigned to one of three groups according to the date of surgery: group 1, 1988-1999; group 2, 2000-2009; and group 3, 2010-2015.

Results

Age at the time of surgery, body mass index, smoking status, incidence of diabetes and hypertension, and the number of incidentally identified renal masses increased significantly over time. The proportion of patients undergoing partial nephrectomy (PN) or minimally invasive surgery (MIS) increased sharply during the last two time periods. From 2010, the rate of robot-assisted nephrectomy rose sharply, occurring in 37.8% of MIS cases. Benign pathology was identified in 1.8% and 5.2% of cases in the middle and last periods, respectively; angiomyolipoma was the most common pathology. In later years, tumors were more often localized, although tumor grade increased. Sub-group analysis of small renal masses ≤4 cm revealed similar trends in operative and pathologic characteristics over time.

Conclusions

Between 1988 and 2015, there was a substantial change in the clinical, operative, and histological characteristics of patients who underwent resection of a renal mass in Korea. The most notable changes were stage migration towards localized disease and widespread use of PN and MIS.

Partial versus Radical Nephrectomy for T1-T2 Renal Cell Carcinoma in Patients with Chronic Kidney Disease Stage III: a Multiinstitutional Analysis of Kidney Function and Survival Rate

BACKGROUND

To examine survival rates and renal function after partial nephrectomy (PN) and radical nephrectomy (RN) in patients with chronic kidney disease (CKD).

METHODS

We studied 4,332 patients who underwent PN or RN for pathological T1a-T2N0M0 renal cell carcinoma from 1988 to 2014. Patients were divided into two subgroups of CKD stage I-II and stage III. Kidney function, and survival outcomes were compared between groups.

RESULTS

We included 1,756 patients with CKD I-II and 276 patients with CKD III in the final pair-matched analysis. Kidney function was significantly better preserved in the PN than in the RN group among all patients. However, the beneficial effect of PN on kidney function gradually disappeared over time in CKD III patients. The 5-year overall survival (OS) rates after PN and RN differed in patients with CKD I-II disease (99.4% vs. 96.5%, respectively, P = 0.015). The 5-year OS rates after surgery were not affected by mode of nephrectomy in CKD III patients (97.8% vs. 93.5%, P = 0.103). The 5-year cancer-specific survival rates did not differ between treatment groups in all CKD stage. Cox hazard analysis showed that the operative method was a significant factor for OS in CKD I-II patients (hazard ratio [HR], 0.320; confidence interval [CI], 0.122-0.840; P = 0.021). However, PN was not beneficial in terms of OS in CKD III patients (HR, 0.395; CI, 0.086-1.172; P = 0.117).

CONCLUSION

PN is associated with a higher OS rate and better kidney function in patients with preoperative CKD stage I and II, but not in those with CKD stage III.

Gender- and cholesterol-specific predictive value of body mass index in renal cell carcinoma: A multicenter study

AIM

Recently, there have been some reports on preoperative body mass index (BMI) and total cholesterol (TC) as a prognostic predictor for patients with renal cell carcinoma (RCC) but the topic is controversial and still poorly understood. So we analyzed the effects of BMI and TC on the prognosis of RCC.

METHODS

Retrospective data from 1988 to 2015 were collected from eight centers with a total of 7,271 patients surgically treated for nonmetastatic RCC. Receiver operating characteristic curve analysis was analyzed and the highest Youden index was shown at 163.5 mg/dL. According to the Asian BMI criteria, patients were divided into normal BMI < 25 kg/m² and high BMI ≥ 25 kg/m² . Kaplan-Meier analysis, multivariate Cox regression model were performed to identify the overall survival (OS) and the recurrence-free survival (RFS).

RESULTS

Normal BMI and low TC group was associated with the shortest OS and RFS as compared to the other groups significantly. In the male patients, the results showed similar to the whole sample. But in the female, BMI had no effect on both OS and RFS. On multivariate Cox regression analysis, low TC was an independent predictor for OS in both genders. However, normal BMI was a significant prognostic factor in the males only.

CONCLUSION

Preoperative BMI and TC are good predictive factors for both OS and RFS significantly in RCC patients. Also, TC was an independent predictor for OS in all RCC patients; however, BMI was a significant predictor in males only.

Age-dependent prognostic value of body mass index for non-metastatic clear cell renal cell carcinoma: A large multicenter retrospective analysis

BACKGROUND AND OBJECTIVES

The prognostic value of obesity is unestablished for renal cell carcinoma. We assessed the age-dependent prognostic value of body mass index (BMI) in a large multicenter cohort of patients with non-metastatic clear cell renal cell carcinoma (nm-cRCC).

METHODS

This study evaluated 2092 patients with nm-cRCC who underwent surgery with curative intent at five Korean institutions between 2001 and 2014.

RESULTS

There was no significant difference in BMI between the young (<45 years) and older patients (≥45 years) (P = 0.398). Among older patients, high BMI (≥25 kg/m² ) was associated with better 5-year rates of recurrence-free survival (RFS) and cancer-specific survival (CSS) (P = 0.003 and 0.004, respectively), and multivariate analysis confirmed that high BMI was independently associated with better RFS and CSS (RFS hazard ratio [HR]: 0.617, P = 0.005; CSS HR: 0.588, P = 0.024). However, among young patients, there were no significant BMI-related differences in the 5-year RFS and CSS rates (P = 0.457 and 0.420, respectively), and high BMI was not independently associated with RFS or CSS (P = 0.822 and 0.749, respectively).

CONCLUSIONS

Among patients with nm-cRCC, high BMI was associated with a favorable prognosis among older patients but not among young patients. Therefore, the relationship between obesity and nm-cRCC prognosis might vary according to age.

Renal capsular invasion is a prognostic biomarker in localized clear cell renal cell carcinoma

Renal capsular invasion (RCI) and lymphovascular invasion (LVI) are potential prognostic factors of significance in renal cell carcinoma (RCC). We evaluated the independent prognostic implications of RCI and LVI in localized clear cell RCC based on a large multi-institutional cohort. 6, 849 patients who had undergone radical or partial nephrectomy for RCC were included. Associations between recurrence and RCI or LVI were analyzed by constructing statistical models that combined Cox proportional hazard regression and propensity score matching. To analyze RCI, 2, 733 patients including 603 patients with RCI were enrolled. To analyze LVI, 3, 586 patients including 121 patients with LVI were enrolled. Recurrence was observed in 75 (12.4%) patients with RCI and 134 (6.3%) patients without RCI. In all statistical models, RCI was significantly associated with an increased risk of recurrence. Recurrence was observed 29 (24.0%) patients with LVI and 207 (6.0%) patients without LVI. LVI was significantly associated with an increased risk of recurrence only in non-adjusted univariate models, but not in multivariate adjusted analysis or propensity score matching models. In conclusion, these findings suggest that RCI could be a significant risk factor for localized clear cell RCC recurrence. In contrast to RCI, LVI cannot be an independent prognostic variable.

Sex-Specific Prognostic Significance of Obesity in Nonmetastatic Clear-Cell Renal-Cell Carcinoma in Korea: A Large Multicenter Cohort Analysis

INTRODUCTION

We assessed the prognostic significance of obesity in relation to sex in patients with nonmetastatic clear-cell renal-cell carcinoma (nm-cRCC) in a large multicenter setting in Korea.

PATIENTS AND METHODS

A total of 2097 patients with nm-cRCC who underwent surgery with curative intent were enrolled from 6 institutions in Korea between April 2000 and February 2014. Obesity was determined by body mass index (BMI) before surgery. BMI was used as a continuous variable and was categorized as normal (≥ 18.5 to < 25.0 kg/m2, normal BMI) and overweight or obese (≥ 25 kg/m2, high BMI). The relationships between BMI, sex, recurrence-free survival (RFS), and cancer-specific survival (CSS) were evaluated.

RESULTS

Male patients had a greater high BMI ratio than female patients (P = .030). In men, the 5-year RFS and CSS rates in the high BMI group were greater than those in the normal BMI group (P = .003 and .006, respectively). Multivariate analyses revealed that in men, a high BMI was associated with greater RFS or CSS rates (hazard ratio: RFS, 0.901, P = .001; CSS, 0.822, P < .001). In women, there were no significant differences in the 5-year RFS and CSS rates according to BMI (P = .531 and .323, respectively), and high BMI was not associated with RFS or CSS (P = .250 and .180, respectively).

CONCLUSION

In patients with nm-cRCC, obesity was a favorable prognosticator in male but not female patients. Therefore, the association between obesity and nm-cRCC prognosis might differ by sex.

Impact of preoperative thrombocytosis on prognosis after surgical treatment in pathological T1 and T2 renal cell carcinoma: results of a multi-institutional comprehensive study

Background

The prognostic significance of preoperative thrombocytosis (TC) in renal cell carcinoma (RCC) is not without some debate. The aim of the present multi-institutional study was to determine the association of preoperative TC with the clinicopathological features and prognosis of localized RCC patients who underwent surgery in a large cohort.

Methods

A study involving 8 institutions, and 4,376 patients with pT1 and pT2 RCC from the Korean renal cell carcinoma (KORCC) database, was conducted. TC was defined as a platelet count ≥400,000/μL. Patients were divided into 2 groups based on the presence of preoperative TC. Clinicopathological variables and survival rates were compared between the 2 groups.

Results

Out of the 4,376 patients in the study, 106 (2.4%) had preoperative TC. Compared to patients without TC, these patients had a lower body mass index. Additionally, these patients had more advanced stage tumors with a higher Fuhrman grade, and higher incidence of symptoms at the time of diagnosis. Kaplan-Meier curves revealed that patients with TC had a significantly lower rate of recurrence-free survival (RFS). Furthermore, a lower rate of overall survival (OS) was exhibited amongst patients with TC. Multivariate analysis revealed that TC was an independent prognostic factor in terms of the RFS and OS.

Conclusions

TC appeared to be an important prognostic determinant in localized RCC. Furthermore, preoperative platelet count may be clinically useful for risk stratification of patients with surgically treated localized RCC.

Impact of Young Age at Diagnosis on Survival in Patients with Surgically Treated Renal Cell Carcinoma: a Multicenter Study

The prognostic significance of age in renal cell carcinoma (RCC) is a subject of debate. The aim of the present multi-institutional study was to evaluate the impact of age on clinicopathological features and survival in a large cohort of patients with RCC. A total of 5,178 patients who underwent surgery for RCC at eight institutions in Korea between 1999 and 2011 were categorized into three groups according to age at diagnosis as follows: young age (< 40 years, n = 541), middle-age (≥ 40 and < 60 years, n = 2,551), and old age (≥ 60 years, n = 2,096) groups. Clinicopathological variables and survival rates were compared between the three groups. Young patients had lower stage tumors with a low Fuhrman grade, a lower rate of lymphovascular invasion than patients in the other age groups. Regarding histologic type, the young age group had a lower percentage of clear cell histology and a greater incidence of Xp11.2 translocation RCC. Kaplan-Meier estimates showed that cancer-specific survival was significantly better in the young age group than in the other groups (log rank test, P = 0.008). However, age at diagnosis was not an independent predictor of survival in multivariate analysis. In conclusion, young age at diagnosis was associated with favorable pathologic features, although it was not an independent prognostic factor for survival in patients with surgically-treated RCC. Age itself should not be regarded as a crucial determinant for the treatment of RCC.

Prognostic Significance of Preoperative Neutrophil-to-Lymphocyte Ratio in Nonmetastatic Renal Cell Carcinoma: A Large, Multicenter Cohort Analysis

Background. The prognostic significance of the neutrophil-to-lymphocyte ratio (NLR) in nonmetastatic renal cell carcinoma (non-mRCC) is controversial, although NLR has been established as a prognostic factor in several cancers. The objective of our study was to assess the prognostic significance of preoperative NLR in non-mRCC, based on a large, multicenter cohort analysis. Methods. Totally, 1,284 non-mRCC patients undergoing surgery were enrolled from six institutions between 2000 and 2014. Recurrence-free survival (RFS) and cancer-specific survival (CSS) were calculated, and the prognostic significance of NLR was evaluated. Results. Patients with higher NLR had larger tumors (p < 0.001), higher T stage (p < 0.001), worse Eastern Cooperative Oncology Group performance status (p < 0.001), worse symptoms (p = 0.003), sarcomatoid differentiation (p = 0.004), and tumor necrosis (p < 0.001). The 5-year RFS and CSS rates were significantly lower in patients with high NLR than in those with low NLR (each p < 0.001). Multivariate analysis identified NLR to be an independent predictor of RFS and CSS (each p < 0.05). Moreover, predictive accuracy of multivariate models for RFS and CSS increased by 2.2% and 4.2%, respectively, with NLR inclusion. Conclusions. Higher NLR was associated with worse clinical behavior of non-mRCC. Also, NLR was a significant prognostic factor of both RFS and CSS.