Impact of Clinical and Histopathological Parameters on Disease Specific Survival in Patients with Collecting Duct Renal Cell Carcinoma: Development of a Disease Specific Risk Model

Establishment of a nomogram to predict the overall survival of patients with collecting duct renal cell carcinoma

BACKGROUND

Collecting duct carcinoma (CDC) is a rare histological type of renal cell carcinoma that lacks a prognostic prediction model. In this study, we developed a nomogram to predict the prognosis of CDC patients.

METHODS

Data for patients (n = 247) diagnosed with CDC from 2004 to 2015 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database, and the patients were randomized into training (n = 165) and validation (n = 82) cohorts. Survival outcomes were evaluated by the Kaplan-Meier method. Significant variables determined by univariate and multivariate Cox regression analyses were used to construct the nomogram. C-indexes and calibration plots were applied to evaluate the performance of the nomogram.

RESULTS

CDC patients had a median overall survival (OS) of 18.0 months (95% confidence interval: 13.7-22.3); 1-year, 3-year, and 5-year OS rates were 58.7%, 34.2%, and 29.4%, respectively. Independent prognostic factors, including age at diagnosis, tumor size, tumor grade, T stage, N stage, M stage, and surgery information, were identified by multivariate analysis. The nomogram was constructed based on significant factors in the training cohort. The C-indexes were 0.769 (training cohort) and 0.767 (validation cohort). The calibration curves for survival rates showed that the predicted and observed values were consistent.

CONCLUSIONS

This study constructed a nomogram to predict prognosis in patients with CDC. The nomogram performed well in predicting the 1-year, 3-year, and 5-year OS, which can help doctors actively monitor and follow up patients.

Collecting duct carcinoma: Epidemiology, clinical characteristics and survival

INTRODUCTION

Collecting duct carcinoma (CDC) is a rare renal malignancy. We relied on a large population-based cohort to address epidemiology, clinical characteristics, and treatment of CDC patients. We also tested survival in the overall cohort, as well as in stage-specific fashion.

MATERIALS AND METHODS

Within Surveillance, Epidemiology, and End Results (2004-2018) database, we identified 399 CDC patients. Based on Kaplan-Meier plots survival estimates, conditional survival rates were derived according to disease stage. Cox regression models tested for predictors of cancer specific mortality (CSM).

RESULTS

Overall, 273 (68.4%) patients were male, 236 (59.2%) had T3-4 stages, 148 (37.1%) had lymph node invasion, and 156 (39.1%) had distant metastases at initial diagnosis. Nephrectomy alone was commonest in stage I-II (n = 91/99, 92%) and III (n = 94/116, 81%). Combination of both nephrectomy and systemic therapy was commonest in stage IV (n = 62/172, 36%). In the overall cohort, median cancer specific survival was 18 months. Provided a disease-free interval of 24 months, five-year Kaplan-Meier estimated survival at diagnosis increased from 74.2 to 91.0% in stage I-II, from 31.1 to 65.3% in stage III, and from 6.3 to 34.1% in stage IV. In multivariable Cox regression models addressing CSM, systemic therapy (Hazard Ratio [HR]: 0.47, P = 0.020), nephrectomy (HR: 0.37, P < 0.001) and combination of both (HR: 0.28, P < 0.001) exhibited a strong protective effect.

CONCLUSION

Despite its highly aggressive phenotype and dismal survival, CDC is sensitive to nephrectomy and/or systemic therapy. Moreover, even for advanced stage, a more favorable prognosis can be achieved in patients, who benefit of disease-free interval after diagnosis and initial treatment.

Tumors masquerading as type 2 papillary renal cell carcinoma: pathologists' ever-expanding differential diagnosis for a heterogeneous group of entities

Although papillary renal cell carcinoma has historically been classified as either type 1 or type 2, data from The Cancer Genome Atlas (TCGA) has demonstrated significant genomic heterogeneity in tumors classified as "type 2 papillary renal cell carcinoma" (T2PRCC). Papillary renal cell carcinoma is expected to have a favorable clinical course compared to clear cell renal cell carcinoma (CCRCC). However, tumors with poor outcome more similar to CCRCC were included in the T2PRCC cohort studied by the TCGA. The differential diagnosis for T2PRCC includes a variety of other renal tumors, including aggressive entities such as TFE3 translocation-associated renal cell carcinoma, TFEB-amplified renal cell carcinoma, fumarate hydratase-deficient renal cell carcinoma, high-grade CCRCC, and collecting duct carcinoma. Accurate classification of these tumors is important for prognostication and selection of therapy.

Updates in Grading of Renal Cell Carcinomas Beyond Clear Cell Renal Cell Carcinoma and Papillary Renal Cell Carcinoma

The World Health Organization (WHO) recommends grading of clear cell renal cell carcinoma (RCC) and papillary RCC using the WHO/International Society of Urological Pathology (ISUP) grade, which is primarily based on nuclear features. As the spectrum of RCC continues to evolve, with more recently described subtypes in the past decade, literature evidence on grading these subtypes is limited or not available for some tumor types. Herein, we outline a pragmatic approach to the topic of grading RCC, dividing the contemporarily described RCC subtypes into 7 categories based on the potential clinical applicability of grading as a useful prognostic parameter: (1) RCC subtypes that are reasonably validated and recommended for WHO/ISUP grading; (2) RCC subtypes where WHO/ISUP is not applicable; (3) RCC subtypes where WHO/ISUP grading is potentially clinically useful; (4) inherently aggressive RCC subtypes where histologic classification itself confers an aggressive biologic potential; (5) renal epithelial tumors where WHO/ISUP grading provides potentially misleading prognostic implication; (6) renal epithelial neoplasms where low WHO/ISUP grade features are a prerequisite for accurate histologic classification; and (7) renal epithelial neoplasms with no or limited data on grading or incomplete understanding of the biologic potential. Our aim in outlining this approach is 2-fold: (a) identify the gaps in understanding and application of grading in RCC subtypes so that researchers in the field may perform additional studies on the basis of which the important pathologic function of assignment of grade may be recommended to be performed as a meaningful exercise across a wider spectrum of RCC; and (b) to provide guidance in the interim to surgical pathologists in terms of providing clinically useful grading information in RCC based on currently available clinicopathologic information.

Impact of Treatment Modalities on Prognosis in Patients With Renal Collecting Duct Carcinoma: A Population-Based Study

Objective

Renal collecting duct carcinoma (CDC) is an extremely rare disease with few studies, and the current understanding of its prognosis is limited. We used the Surveillance, Epidemiology, and End Results (SEER) registry data to explore the prognostic factors and effect of treatment modalities on the overall survival (OS) and cancer-specific survival (CSS) in patients with CDC.

Methods

Patients’ information of CDCs diagnosed by pathological examination between 2000 and 2018 was extracted from the SEER database. The Kaplan–Meier method was used to calculate OS and CSS and log-rank tests to evaluate the differences in OS and CSS. The associations between clinicopathological variables and survival outcomes were assessed with the Cox proportional hazard model. A directed acyclic graph (DAG) was drawn to recognize confounding factors and to obtain the multivariable regression model, and the impact of surgery, radiotherapy, and chemotherapy on OS and CSS was analyzed, respectively.

Results

A total of 242 patients with CDC were enrolled. The median OS and CSS time were 17 and 21 months, respectively. The OS rates at 1, 2, and 5 years were 56.9%, 41.9%, and 30.0%, respectively, while the CSS rates at 1, 2, and 5 years were 60.1%, 47.5%, and 34.8%, respectively. Patients who had a large tumor size, poor pathological grade, and advanced TNM classification exhibited worse survival outcomes. Univariable and multivariable Cox regression analyses revealed that surgery, chemotherapy, T stage, N stage, and M stage were independent prognostic factors for OS and CSS. The DAG-guided multivariate Cox regression model revealed that surgery and chemotherapy improved OS and CSS.

Conclusions

CDC is an exceedingly rare disease and has malignant behavior. Most patients have a high pathological grade and advanced TNM stage at diagnosis and exhibited poor survival. Resection of all visible tumors including metastatic lesions or chemotherapy can be beneficial to prognosis, while healthier benefits are less likely to receive radiotherapy. More relevant studies with larger samples are needed to verify the value of surgery and adjuvant therapy in the treatment of CDCs.

Start of a New Era: Management of Non-Clear Cell Renal Cell Carcinoma in 2022

Purpose of Review

Historically, kidney cancer was diagnosed as either clear cell renal carcinoma (ccRCC) or non-clear cell renal carcinoma (nccRCC). With further research into the pathophysiology of nccRCC, multiple distinct subtypes have emerged creating distinct diagnosis, such as papillary renal cell carcinoma (PRCC), chromophobe renal cell carcinoma (crRCC), or unclassified carcinoma (cRCC). Many other kidney cancer subtypes are now included in the WHO classification system.

Recent Findings

The prognosis for each of the more frequently diagnosed types is discussed here along with treatment recommendations. The available clinical trial results and salient retrospective studies of each subtype are reviewed here to guide clinicians on the optimal treatment selection for patients with these rare histologic types or RCC.

Summary

Many nccRCC types are now recognized and each has unique molecular drivers which are different than ccRCC. The optimal treatment strategy is different for each subtype. The prognosis also differs based on the histology.

A Novel Machine Learning Algorithm Combined With Multivariate Analysis for the Prognosis of Renal Collecting Duct Carcinoma

Objectives

To investigate the clinical and non-clinical characteristics that may affect the prognosis of patients with renal collecting duct carcinoma (CDC) and to develop an accurate prognostic model for this disease.

Methods

The characteristics of 215 CDC patients were obtained from the U.S. National Cancer Institute’s surveillance, epidemiology and end results database from 2004 to 2016. Univariate Cox proportional hazard model and Kaplan-Meier analysis were used to compare the impact of different factors on overall survival (OS). 10 variables were included to establish a machine learning (ML) model. Model performance was evaluated by the receiver operating characteristic curves (ROC) and calibration plots for predictive accuracy and decision curve analysis (DCA) were obtained to estimate its clinical benefits.

Results

The median follow-up and survival time was 16 months during which 164 (76.3%) patients died. 4.2, 32.1, 50.7 and 13.0% of patients were histological grade I, II, III, and IV, respectively. At diagnosis up to 61.9% of patients presented with a pT3 stage or higher tumor, and 36.7% of CDC patients had metastatic disease. 10 most clinical and non-clinical factors including M stage, tumor size, T stage, histological grade, N stage, radiotherapy, chemotherapy, age at diagnosis, surgery and the geographical region where the care delivered was either purchased or referred and these were allocated 95, 82, 78, 72, 49, 38, 36, 35, 28 and 21 points, respectively. The points were calculated by the XGBoost according to their importance. The XGBoost models showed the best predictive performance compared with other algorithms. DCA showed our models could be used to support clinical decisions in 1-3-year OS models.

Conclusions

Our ML models had the highest predictive accuracy and net benefits, which may potentially help clinicians to make clinical decisions and follow-up strategies for patients with CDC. Larger studies are needed to better understand this aggressive tumor.

Persistent Response to a Combination Treatment Featuring a Targeted Agent and an Immune Checkpoint Inhibitor in a Patient With Collecting Duct Renal Carcinoma: A Case Report and Literature Review

Collecting duct carcinoma (CDC) is a rare and highly aggressive subtype of kidney cancer that is associated with a poor prognosis. At present, there is no effective treatment for CDC. Herein, we report a case of metastatic CDC treated with a combination of a tyrosine kinase inhibitor and an immune checkpoint inhibitor. A 67-year-old male was diagnosed with CDC with lung and bone metastasis. Pazopanib and camrelizumab were administered after cytoreductive nephrectomy. The patient achieved a partial response after one cycle of treatment; however, he then experienced serious drug-induced hepatic injury. Therefore, we discontinued camrelizumab and administered monotherapy with pazopanib. Three months later, the cancer had progressed and axitinib and sintilimab were administered. The patient achieved a partial response, accompanied by the complete disappearance of the metastatic lesion in the lung. The patient had an excellent physical status after 11 months. This is the first reported case of metastatic CDC successfully treated with a combination of a tyrosine kinase inhibitor and an immune checkpoint inhibitor. This form of combination treatment may be an effective option for treating metastatic CDC.

Prognostic Factors and a Nomogram Predicting Overall Survival and Cancer-Specific Survival for Patients with Collecting Duct Renal Cell Carcinoma

Background

Collecting duct renal cell carcinoma (CDRCC) is a rare type of renal cancer characterized by a poor prognosis. The aim of this work was to develop a nomogram predicting the overall survival (OS) and cancer-specific survival (CSS) for patients with CDRCC.

Methods

A total of 324 eligible patients diagnosed with CDRCC from 2004 to 2015 were identified using the data from the Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan-Meier curve was used to estimate the 1-, 3-, and 5-year OS and CSS of these patients. Univariate and multivariate Cox regression models were performed to identify the independent risk factors associated with OS and CSS. The nomogram was developed based on these factors and evaluated by the concordance index (C-index) and calibration curves using the bootstrap resample method. The predictive accuracy of the nomogram was also compared with the manual of the American Joint Committee on Cancer (AJCC).

Results

The estimated 1-, -3, and 5-year OS and CSS rates in the analytic cohorts were 56.4% and 60%, 32.5% and 37.3%, and 28.7% and 33.6%, respectively. The multivariate model revealed that age, tumor size, tumor grade, N stage, M stage, surgical type, and chemotherapy were independent predicted factors for OS, while tumor size, tumor grade, N stage, M stage, surgical type, and chemotherapy were independently linked to CSS. A nomogram was developed using these factors with relatively good discrimination and calibration. The C-index for OS and CSS was 0.764 (95% CI: 0.735~0.793) and 0.783 (95% CI: 0.754~0.812), which was superior to the AJCC stage (C-index: 0.685 (95% CI: 0.654~0.716) and 0.703 (95% CI: 0.672~0.734)). Patients were divided into low-risk, intermediate-risk, and high-risk groups according to the total points calculated by the nomogram. Patients in the low-risk group (97 mo and not reached) experienced significantly long median OS and CSS compared to the intermediate-risk (17 mo and 18 mo) and high-risk groups (5 mo for both). The calibration curves showed a good agreement between the predicted and actual probability related to OS and CSS.

Conclusion

CDRCC has an aggressively biologic behavior with relatively poor prognosis. A survival prediction nomogram making an individualized evaluation of OS and CSS in patients with CDRCC was presented, potentially helping urologists to make a better risk stratification.

Collecting duct carcinoma: A single-institution retrospective study

PURPOSE

Collecting duct carcinoma is a rare pathologic entity with a paucity of clinical data in the literature. We aim to evaluate our institutional experience with the management of this disease.

MATERIALS AND METHODS

All renal tumors in the Mayo Clinic Nephrectomy Registry were re-reviewed retrospectively by an expert urologic pathologist. Cases of collecting duct carcinoma were identified. Descriptive statistics were used to characterize these cases. Overall survival and metastases-free survival were estimated using Kaplan-Meier methodology.

RESULTS

Between 1970 and 2018, a total of 21 cases were identified with an incidence of 0.2%. Cases were seen predominantly in men (N = 17, 81%) with a median age at diagnosis of 57 years old. At the time of nephrectomy, high grade disease (grade 3 or 4) was noted in the majority of patients (90%). The median times to local recurrence and distant metastases were 5.6 and 5.1 months, respectively. Median overall survival occurred at 1.5 years. Median distant metastases-free survival among M0 patients occurred at 0.5 years. Four patients with localized disease and small tumor size who underwent nephrectomy lived longer than 10 years. No systemic therapies achieved a durable response in the metastatic setting.

CONCLUSION

The Mayo Clinic nephrectomy registry contains 21 patients with collecting duct carcinoma over nearly 50 years. Early local recurrence and distant metastases were seen after nephrectomy. However, M0 patients with a small tumor may have long-term benefits from nephrectomy. Neither chemotherapy nor targeted therapy resulted in a durable response in the metastatic setting.

Incidence, Clinical Characteristics, and Survival of Collecting Duct Carcinoma of the Kidney: A Population-Based Study

Objective

To investigate the exact age‐adjusted incidence (AAI), clinical characteristics, and survival data of collecting duct carcinoma of the kidney (CDCK) recorded in the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute.

Methods

Patients with CDCK confirmed by microscopic examination from 2004 to 2018 were selected from the SEER database. AAI rates were calculated using SEER*Stat software (version 8.3.9). The Kaplan‐Meier method was used to evaluate cancer-specific survival (CSS) rates according to tumor size, tumor stage, and treatment methods, and differences among these variables were assessed by the log‐rank test. Cox regression analysis was employed to identify variables independently related to CSS.

Results

A total of 286 patients with CDCK were identified from the database. The majority of the patients were white (69.2%), male (67.5%), and married (60.5%), and the median age was 59 years. Most patients with CDCK (74.4%) presented with stages III or IV disease. The diameter of most (59.4%) tumors was less than 7 cm, and the tumors were more commonly found on the left than on the right (55.2% vs. 44.8%). The incidence of CDCK decreased over time. The median CSS time was 17 months. In terms of the treatment modalities used, 83.9% of the patients underwent surgery; 32.9% underwent chemotherapy, and 13.6% underwent radiotherapy. The CSS rates at 1, 2, and 5 years were 57.3%, 43.2%, and 30.7%, respectively. In patients with stage IV CDCK treated with surgery alone, chemotherapy alone, and surgery plus chemotherapy, the median survival time was 5 months, 9 months, and 14 months, respectively (P =0.024). Multivariate Cox regression analysis showed surgery, chemotherapy, stage, regional lymph node metastasis, and distant metastasis were independent prognostic factors for patients with CDCK.

Conclusions

CDCK is an uncommon malignant renal carcinoma, and its incidence is decreasing based on the analysis of current data. CDCK is a high stage, regional lymph-nodes positive, and metastatic disease. Compared with surgery alone or chemotherapy alone, patients with stage IV could gain survival benefit from surgery combined with chemotherapy.

Imaging analysis of 13 rare cases of renal collecting (Bellini) duct carcinoma in northern China: a case series and literature review

Background

Collecting (Bellini) duct carcinoma (CDC) is a highly malignant and rare kidney tumor. We report our 12-year experience with CDC and the results of a retrospective analysis of patients and tumor characteristics, clinical manifestations, and imaging features by computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT.

Methods

Retrospective examination of tumors between January 2007 and December 2019 identified 13 cases of CDC from three medical centers in northern China. All 13 patients underwent CT scan, among which eight underwent dynamic enhanced CT scan, two underwent PET/CT scan, and one underwent magnetic resonance cholangiopancreatography (MRCP) examination. The lesions were divided into nephritis type and mass type according to the morphology of the tumors.

Results

The study group included ten men and three women with an average age of 64.23 ± 10.74 years. The clinical manifestations were gross hematuria, flank pain, and waist discomfort. The mean tumor size was 8.48 ± 2.48 cm. Of the 13 cases, six (46.2%) were cortical-medullary involved type and seven (53.8%) were cortex–medullary–pelvis involved type. Eleven (84.6%) cases were nephritis type and two (15.4%) were mass type. The lesions appeared solid or complex solid and cystic on CT and MRI. The parenchymal area of the tumors showed isodensity or slightly higher density on unenhanced CT scan in the 13 cases. PET/CT in two cases showed increased radioactivity intake. Evidence of intra-abdominal metastatic disease was present on CT in nine (69.2%) cases.

Conclusions

The imaging characteristics of CDC differ from those of other renal cell carcinomas. In renal tumors located in the junction zone of the renal cortex and medulla that show unclear borders, slight enhancement, and metastases in the early stage, a diagnosis of CDC needs to be considered. PET/CT provides crucial information for the diagnosis of CDC, as well as for designing treatment strategies including surgery.

The Relationship Between Tumor-Stroma Ratio, the Immune Microenvironment, and Survival in Patients With Spinal Chordoma

BACKGROUND

Currently, little is known about the clinical relevance of tumor-stroma ratio (TSR) in chordoma and data discussing the relationship between TSR and immune status of chordoma are lacking.

OBJECTIVE

To characterize TSR distribution in spinal chordoma, and investigated its correlation with clinicopathologic or immunological features of patients and outcome.

METHODS

TSR was assessed visually on hematoxylin and eosin-stained sections from 54 tumor specimens by 2 independent pathologists. Multiplex immunofluorescence was used to quantify the expression levels of microvessel density, Ki-67, Brachyury, and tumor as well as stromal PD-L1. Tumor immunity status including the Immunoscore and densities of tumor-infiltrating lymphocytes (TILs) subtypes were obtained from our published data and reanalyzed.

RESULTS

Bland-Altman plot showed no difference between mean TSR derived from the two observers. TSR was positively associated with stromal PD-L1 expression, the Immunoscore and CD3+ as well as CD4+ TILs density, but negatively correlated with tumor microvessel density, Ki-67 index, surrounding muscle invasion by tumor and number of Foxp3+ and PD-1+ TILs. Low TSR independently predicted poor local recurrence-free survival and overall survival. Moreover, patients with low TSR and low Immunoscore chordoma phenotype were associated with the worst survival. More importantly, combined TSR and Immunoscore accurately reflected prognosis and enhanced the ability of TSR or Immunoscore alone for outcome prediction.

CONCLUSION

These data reveal the significant impact of TSR on tumor progression and immunological response of patients. Subsequent use of agents targeting the stroma compartment may be an effective strategy to treat chordoma especially in combination with immune-based drugs.

Collecting ducts carcinoma: An orphan disease. Literature overview and future perspectives

Collecting ducts carcinoma (CDC) is a rare and aggressive histological subtype of renal cancer accounting for only 1% of renal tumors. Usually patients present in bad clinical conditions due to a symptomatic disease with synchronous metastasis. Due to the rarity of CDC, data from prospective trials evaluating the best treatment for these patients are limited. The prognosis is poor with a median overall survival of around 11 months for patients with metastatic disease. The best treatment option today is considered a doublet chemotherapy with platinum salt plus gemcitabine as a result from a prospective phase II trial, but survival outcomes remain unsatisfactory. The interest in the in-depth understanding the biology of this orphan disease is growing, leading to find potential new biological-driven treatment approaches. Here we review the up-to-date literature evidences to address the best management of this rare and unfavorable clinical condition.

Bilateral kidneys involvement of collecting duct carcinoma with cystic change: A case report

RATIONALE

Collecting duct carcinoma (CDC) is a rare neoplasm arising from the collecting duct and should be distinguished from other renal cell carcinomas that mostly originated from the proximal tubular epithelium and tumors originated from the urothelium. It usually occurs in unilateral kidney, sometimes found with cystic change.

PATIENT CONCERNS

We present the case of a 53-year-old male suffering from repeated bilateral flank pain for 6 months, increased pain with dysuria for 5 days.

DIAGNOSIS

Ultrasound showed 2 similar hybrid echo masses in bilateral kidneys with enlarged lymph nodes surrounded, which accords with magnetic resonance imaging (MRI), and intraoperative biopsy reported malignancy.

INTERVENTIONS

An exploratory operation was performed and the mass on the left kidney was removed, but pathological result reported collecting duct carcinoma according to the morphological features and immunohistochemical tests. Also postsurgery positron emission tomography-computed tomography (PET-CT) confirmed the mass on the left kidney is also a lesion of CDC.

OUTCOMES

The patient refused chemotherapy and had an overall survival of 7 months.

LESSONS

We presented a case of CDC involving bilateral kidneys with cystic change; this is the first case of bilateral renal occurrence with cystic change to our knowledge. Because of CDC's rapid growth and the lack of effective adjuvant treatment after surgery, the prognosis is poor and the diagnosis should be made carefully.

Collecting duct carcinoma of the kidney is associated with CDKN2A deletion and SLC family gene up-regulation

The genetic landscape and molecular features of collecting duct carcinoma (CDC) of the kidney remain largely unknown. Herein, we performed whole exome sequencing (WES) and transcriptome sequencing (RNASeq) on 7 CDC samples (CDC1 −7). Among the 7 samples, 4 samples with matched non-tumor tissue were used for copy number analysis by SNP array data. No recurrent somatic SNVs were observed except for MLL, which was found to be mutated (p.V297I and p.F407C) in 2 samples. We identified somatic SNVs in 14 other cancer census genes including: ATM, CREBBP, PRDM1, CBFB, FBXW7, IKZF1, KDR, KRAS, NACA, NF2, NUP98, SS18, TP53, and ZNF521. SNP array data identified a CDKN2A homozygous deletion in 3 samples and SNV analysis showed a non-sense mutation of the CDKN2A gene with unknown somatic status. To estimate the recurrent rate of CDKN2A abnormalities, we performed FISH screening of additional samples and confirmed the frequent loss (62.5%) of CDKN2A expression. Since cisplatin based therapy is the common treatment option for CDC, we investigated the expression of solute carrier (SLC) family transporters and found 45% alteration. In addition, SLC7A11 (cystine transporter, xCT), a cisplatin resistance associated gene, was found to be overexpressed in 4 out of 5 (80%) cases of CDC tumors tested, as compared to matched non-tumor tissue. In summary, our study provides a comprehensive genomic analysis of CDC and identifies potential pathways suitable for targeted therapies.

[Bellini duct carcinoma: a new case study and literature review]

Bellini duct carcinoma is a very rare type of renal cell carcinoma (RCC), accounting for less than 1%. It arises from the distal nephron, more specifically from the collecting duct. Its morphological features are extremely variable, making its diagnosis difficult. We report the case of a 62-year old patient admitted with a painless progressive left flank swelling. CT scan showed a huge mass occupying the upper portion of the left kidney. The patient underwent radical nephrectomy. Anatomopathological examination showed collecting duct carcinoma of the kidney. Patient's evolution was exceptionally favorable: no recurrence, no locoregional metastasis and no distant metastasis.

Collecting duct carcinoma of the kidney: Disease characteristics and treatment outcomes from the National Cancer Database

OBJECTIVE

To use a large population-level database to assess survival outcomes for collecting duct renal cell carcinoma (CDRCC).

MATERIALS AND METHODS

The National Cancer Database was queried for all cases of CDRCC and clear cell renal cell carcinoma (CCRCC) from 2004 to 2013. After removing patients with other cancer diagnoses, the analytic cohort was composed of 201,686 CCRCC and 577 CDRCC cases. Kaplan-Meier and cox proportional hazards analysis were employed to model survival.

RESULTS

Compared to CCRCC, patients with CDRCC presented with higher grade and stage, node positive, and metastatic disease (70.7% vs. 30.0% with metastasis; P<0.001). Overall median survival for CDRCC was 13.2 months (95% CI: 11.0-15.5) compared to the 122.5 months (95% CI: 121.0-123.9) for CCRCC. On multivariate analysis of the CDRCC cohort, increasing T stage, high-grade disease, and metastasis were predictors of mortality. Of 184 patients with metastatic CDRCC, 113 underwent cytoreductive nephrectomy (CNx) whereas the rest were treated with chemo/radiation or observed. Survival outcomes were improved in patients who received both CNx with chemo/radiation compared to CNx alone (hazard ratio = 0.51, 95% CI: 0.32-0.79) or chemo/radiation alone (hazard ratio = 0.57, 95% CI: 0.37-0.89) on multivariate analysis.

CONCLUSION

CDRCC is an aggressive subtype of renal cell carcinoma. Median survival is 13 months after diagnosis, drastically lower than for CCRCC. More than 70% of patients have metastatic disease at diagnosis. Chemo/radiation in addition to CNx is associated with a survival benefit over single mode therapy.

Clinicopathologic and Molecular Pathology of Collecting Duct Carcinoma and Related Renal Cell Carcinomas

Collecting duct carcinoma (CDC) and related tumors [ie, renal medullary carcinoma (RMC)] are rare types of highly aggressive renal cell carcinomas (RCC) with poor prognosis. Because of the rarity and diagnostic uncertainty of them, their molecular pathology and significance have not yet been fully elucidated. CDC, RMC, fumarate hydratase-deficient RCC (including hereditary leiomyomatosis and RCC-associated RCC HLRCC-RCC), and recently reported anaplastic lymphoma kinase (ALK)-rearrangement RCC have significant morphologic overlaps, but they are separately distinct entities having different molecular pathway and clinical settings. CDC is more likely to occur in middle to old age population with immunoreactivity for PAX8 and integrase interactor-1 proteins (INI-1). Various chromosomal and genomic alterations have been reported with inconsistent results. In contrast, RMC is more likely to occur in younger patients with sickle cell trait. In RMC, loss of INI-1 expression and OCT3/4 expression are distinguished compared with other RCCs. Finally, ALK-rearrangement RCC seems to have 2 different clinical settings, one with sickle cell trait (VCL-ALK fusion) and the other without (other fusions such as TPM3-ALK, EML4-ALK, and STRN-ALK fusions). Interestingly, VCL-ALK fusion was found in pediatric patients with sickle cell trait, whereas other fusions were detected in adolescent or adult without sickle cell trait. Taken together, CDC and related tumors such as RMC, fumarate hydratase-deficient RCC (including hereditary leiomyomatosis and RCC-associated RCC), and ALK-rearrangement RCC are the distinct entities and their recognition is important for the development of future personalized therapeutic options. This review updates the clinicopathologic features of these tumors with overlapping morphology and outcome.

Genetic and Chromosomal Aberrations and Their Clinical Significance in Renal Neoplasms

The most common form of malignant renal neoplasms is renal cell carcinoma (RCC), which is classified into several different subtypes based on the histomorphological features. However, overlaps in these characteristics may present difficulties in the accurate diagnosis of these subtypes, which have different clinical outcomes. Genomic and molecular studies have revealed unique genetic aberrations in each subtype. Knowledge of these genetic changes in hereditary and sporadic renal neoplasms has given an insight into the various proteins and signalling pathways involved in tumour formation and progression. In this review, the genetic aberrations characteristic to each renal neoplasm subtype are evaluated along with the associated protein products and affected pathways. The potential applications of these genetic aberrations and proteins as diagnostic tools, prognostic markers, or therapeutic targets are also assessed.

Collecting (Bellini) duct carcinoma: A clinical study of a rare tumour and review of the literature

INTRODUCTION

We report our 15-year experience of Collecting (Bellini) duct carcinoma (CDC). We retrospectively analyzed patient and tumour characteristics, clinical manifestations, surgical techniques, clinical outcomes, and salvage therapies.

METHODS

From January 1999 to December 2013, 1042 patients underwent surgical resection of renal neoplasm. We examined all renal tumors and identified 10 cases (0.96%) of CDC.

RESULTS

The study group included 8 men and 2 women, with a median age of 62.5 years. Of these 10 patients, 9 were symptomatic (90%). All patients were treated with open nephrectomy. The mean tumour size was 5.7 cm. The pathologic stages were distributed as follows: pT1b in 2 patients (20%); pT2a in 1 patient (10%); pT3a in 3 patients (30%); and pT3b in 4 patients (40%). Grading was assessed according to Fuhrman scale as follows: grade II in 1 patient (10%); grade III in 3 patients (30%); grade IV in 5 patients (50%); undetermined grade in 1 patient (10%). Four patients (40%) relapsed locally. The median time of local recurrence was 4.9 months. Distant metastases occurred in 9 patients (90%): 4/9 at the time of diagnosis and 5/9 after nephrectomy. The median time of distant metastases after surgery was 8.1 months. Six patients received chemotherapy (gemcitabine plus platinum salts). Radiotherapy was performed in 5 patients. One patient had surgery because of local recurrence and 2 patients were irradiated in the area of the local recurrence. The median overall survival was 7.6 months, and only 2 patients survived more than 2 years after the nephrectomy.

CONCLUSIONS

CDCs of the kidney are aggressive and they have a low survival rate. All patients in our study experienced a relapse of their disease. Local recurrence preceded distant metastases. Results of salvage treatments were poor.

Understanding pathologic variants of renal cell carcinoma: distilling therapeutic opportunities from biologic complexity

CONTEXT

Once believed to represent a uniform malignant phenotype, renal cell carcinoma (RCC) is now viewed as a diverse group of cancers that arise from the nephron.

OBJECTIVE

To review the pathologic characteristics, clinical behavior, molecular biology, and systemic therapy options of recognized RCC histologic subtypes.

EVIDENCE ACQUISITION

A systematic review of English-language articles was performed using the Medline and Web of Science databases. Manuscripts were selected with consensus of the coauthors and evaluated using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria.

EVIDENCE SYNTHESIS

The major findings of the evaluated manuscripts are discussed with an emphasis on the description of the pathologic features, clinical behavior, prognosis, and therapeutic strategies.

CONCLUSIONS

Classification schemes for kidney cancer have undergone dramatic changes over the past two decades. Improvements in these classification schemes are important, as pathologic variants differ not only in disease biology, but also in clinical behavior, prognosis, and response to systemic therapy. In the era of genomic medicine, further refinements in characterization of RCC subtypes will be critical to the progress of this burgeoning clinical space.

PATIENT SUMMARY

Kidney cancer can be subdivided into related but different cancers that arise from the kidney's tubules. In this article we review current classifications for kidney cancer, discuss their characteristics, and provide an overview of each subtype's clinical behavior and treatment. We stress that each subtype harbors unique biology and thus responds differently to available treatment strategies.

Collecting duct carcinomas represent a unique tumor entity based on genetic alterations

Collecting duct carcinoma (CDC) is a rare renal neoplasm that is associated with poor prognosis due to its highly aggressive course and limited response to immuno- or chemotherapy. Histologically, CDC is defined as a subtype of renal cell carcinomas, but in some cases, it is difficult to differentiate from urothelial carcinomas (UC). Therefore the aim of this study was to determine genetic alterations of CDC in comparison to that of urothelial carcinomas of the upper urinary tract (UUT-UC) to clarify the histological origin of this rare tumor entity. Twenty-nine CDC samples were obtained from seven different German centers and compared with twenty-six urothelial carcinomas of the upper urinary tract. Comparative genomic hybridization (CGH) was used to investigate the genetic composition of patients’ tumors and allowed the detection of losses and gains of DNA copy numbers throughout the entire genome. The clinical data were correlated with CGH results. CGH analysis of CDC revealed DNA aberrations in many chromosomes. DNA losses were more frequently observed than gains, while high-level amplifications were not detected. The mean frequency of CDC chromosomal aberrations (4.9/case) was slightly lower than that in UUT-UC (5.4/case). Recurrent CDC DNA losses occurred at 8p (n=9/29), 16p (9/29), 1p (n=7/29) and 9p (n=7/29), and gains occurred in 13q (n=9/29). In contrast to CDC, the most frequently detected UUT-UC DNA aberration was a loss at 9q (n=13/26). DNA losses at 9q, 13q and 8q as well as gains at 8p showed significant variations in UUT-UC compared to CDC. There was no correlation between the patients’ clinical course and the presence or absence of these recurrent genetic alterations. CDCs are characterized by a different genetic pattern compared to UUT-UC. Regarding the published data on renal cell carcinoma, we conclude that CDC appears to be a unique entity among kidney carcinomas.