Nivolumab therapy for metastatic collecting duct carcinoma after nephrectomy: A case report

Italian Registry on Rare Urological Tumors (Meet-URO-23): The First Analysis on Collecting Duct Carcinoma of the Kidney

INTRODUCTION

Rare genitourinary tumors are lacking of randomized and observational data. We aimed to describe the clinical characteristics and outcomes of patients with collecting duct carcinoma (CDC) through the Meet-URO 23/I-RARE database.

MATERIALS AND METHODS

We performed a multicentric retrospective-prospective study within the Meet-URO network, enrolling patients from March 2021 (retrospectively up from 2011) until March 2023. The primary objective was to describe the clinical characteristics of patients with CDC, the secondary objectives were to assess the oncological outcomes in terms of relapse-free survival (RFS), progression-free survival (PFS), overall survival (OS) and objective response rate (ORR) to treatment.

RESULTS

37 patients with CDC were enrolled. Four patients underwent only surgery, 33 received first-line systemic therapy. Median OS was 22.1 months (95% CI, 8.9-31.9). Median RFS for patients with localized disease at onset (n = 30) was 3.7 months (95% CI, 1.9-12.8), median PFS for first-line treatment was 3.3 months (95% CI, 2.7-9.9), with an ORR of 27%. Female sex and good performance status (PS) were associated with longer PFS (P = .072 and P < .01, respectively) and OS (P = .030 and P = .141, respectively).

CONCLUSIONS

Patients with CDC had dismal prognosis, with scarce benefit from the available treatments. Female sex and good PS seemed to be associated with better prognosis.

Comprehensive molecular characterization of collecting duct carcinoma for therapeutic vulnerability

Collecting duct carcinoma (CDC) is an aggressive rare subtype of kidney cancer with unmet clinical needs. Little is known about its underlying molecular alterations and etiology, primarily due to its rarity, and lack of preclinical models. This study aims to comprehensively characterize molecular alterations in CDC and identify its therapeutic vulnerabilities. Through whole-exome and transcriptome sequencing, we identified KRAS hotspot mutations (G12A/D/V) in 3/13 (23%) of the patients, in addition to known TP53, NF2 mutations. 3/13 (23%) patients carried a mutational signature (SBS22) caused by aristolochic acid (AA) exposures, known to be more prevalent in Asia, highlighting a geologically specific disease etiology. We further discovered that cell cycle-related pathways were the most predominantly dysregulated pathways. Our drug screening with our newly established CDC preclinical models identified a CDK9 inhibitor LDC000067 that specifically inhibited CDC tumor growth and prolonged survival. Our study not only improved our understanding of oncogenic molecular alterations of Asian CDC, but also identified cell-cycle machinery as a therapeutic vulnerability, laying the foundation for clinical trials to treat patients with such aggressive cancer.

A case of an advanced renal collecting duct carcinoma in which initial therapeutic effect was achieved with pembrolizumab plus axitinib

Introduction

Renal collecting duct carcinoma is often found in advanced cancers and has a poor prognosis. Here, we present the case of symptomatic metastatic collecting duct carcinoma in which we observed an initial therapeutic effect of immune checkpoint inhibitors plus tyrosine kinase inhibitors.

Case presentation

The patient was a 69-year-old male who was referred to our hospital for examination of a right chest tumor and related pain. Contrast-enhanced computed tomography and tumor biopsy were performed, leading to a diagnosis of collecting duct carcinoma. A combination of pembrolizumab plus axitinib was initiated as first-line therapy; right chest pain decreased, and tumor shrinkage was observed. Seven months after treatment initiation, tumor progression was noted. Cabozantinib was initiated as second-line therapy; however, was discontinued due to patient fatigue. The patient died 15 months after the initiation of treatment.

Conclusion

For symptomatic metastatic collecting duct carcinoma, pembrolizumab plus axitinib may have initial therapeutic effects.

Immune checkpoint inhibitors in non-conventional histologies of renal-cell carcinoma

For years, prospective randomized clinical trials excluded patients with non-conventional histologies of renal cell carcinoma (RCC). The paucity of data has led to adopting the same treatment strategies used for clear-cell RCC (ccRCC). In the present narrative review, we explored state of the art about use of immune checkpoint inhibitors (ICIs) in variant histologies of RCC. According to the results collected, ICIs as monotherapy showed promising antitumor activity in advanced non-clear cell (ncc)RCC. The objective response rate (ORR) was similar to that observed with single-agent anti-PD-1 in the ccRCC population, either in the first-line or the second-line setting, and responder patients experienced an early and durable benefit. Combined ICI-based strategies have shown increasing evidence in nccRCC and robust results in the sarcomatoid variants of RCC. A definitive recommendation about treating non-conventional histologies, either in adjuvant or metastatic settings, should be supported by more extensive dedicated trials.

Gemcitabine plus platinum-based chemotherapy in combination with bevacizumab for kidney metastatic collecting duct and medullary carcinomas: Results of a prospective phase II trial (BEVABEL-GETUG/AFU24)

BACKGROUND

Renal medullary carcinoma (RMC) and collecting duct carcinoma (CDC) are rare entities with a poor outcome. First-line metastatic treatment is based on gemcitabine + platinum chemotherapy (GC) regimen but retrospective data suggest enhanced anti-tumour activity with the addition of bevacizumab. Therefore, we performed a prospective assessment of the safety and efficacy of GC + bevacizumab in metastatic RMC/CDC.

METHODS

We conducted a phase 2 open-label trial in 18 centres in France in patients with metastatic RMC/CDC and no prior systemic treatment. Patients received bevacizumab plus GC up to 6 cycles followed, for non-progressive disease, by maintenance therapy with bevacizumab until progression or unacceptable toxicity. The co-primary end-points were objective response rates (ORRs) and progression-free survival (PFS) at 6 months (ORR-6; PFS-6). PFS, overall survival (OS) and safety were secondary end-points. At interim analysis, the trial was closed due to toxicity and lack of efficacy.

RESULTS

From 2015 to 2019, 34 of the 41 planned patients have been enroled. After a median follow-up of 25 months, ORR-6 and PFS-6 were 29.4% and 47.1%, respectively. Median OS was 11.1 months (95% confidence interval [CI]: 7.6-24.2). Seven patients (20.6%) discontinued bevacizumab because of toxicities (hypertension, proteinuria, colonic perforation). Grade 3-4 toxicities were reported in 82% patients, the most common being haematologic toxicities and hypertension. Two patients experienced grade 5 toxicity (subdural haematoma related to bevacizumab and encephalopathy of unknown origin).

CONCLUSION

Our study showed no benefit for bevacizumab added to chemotherapy in metastatic RMC and CDC with higher than expected toxicity. Consequently, GC regimen remains a therapeutic option for RMC/CDC patients.

[Collecting duct carcinoma and renal medullary carcinoma in the age of new therapies]

Collecting duct carcinoma (also known as Bellini tumour) and renal medullary carcinoma are two extremely rare and aggressive renal cancers. They are both less responsive to conventional treatments used in clear cell renal carcinoma. There are very few studies evaluating their optimal management and currently, at the metastatic stage, polychemotherapy based on platinum salts remains the most widely used. The emergence of new treatments such as anti-angiogenic TKIs, immunotherapy or treatments targeting specific genetic abnormalities, opens up a new field of possibilities in the management of these cancers. The evaluation of the response to these treatments is therefore essential. In this article, we will review the status of their management and the various studies that have evaluated recent treatments in these two cancers.

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.

BONSAI-2 study: Nivolumab as therapeutic option after cabozantinib failure in metastatic collecting duct carcinoma patients

Background:

The BONSAI phase II trial recently demonstrated the activity of cabozantinib in metastatic collecting duct patients. The outcomes of patients in this setting treated with immunotherapy as second-line is unknown. The aim of the present report was to describe outcomes of patients enrolled in the BONSAI trial that received nivolumab as second-line treatment.

Material and methods:

We describe the oncological outcomes in terms of overall response rate, progression-free survival, overall survival and safety. We excluded patients that did not receive any second-line treatment or were treated with agents other than nivolumab.

Results:

We identified five patients of whom one was excluded due to lack of data. Three patients obtained clinical benefit (one partial response, two stable disease); the second-line progression-free survival (nivolumab) ranged from 2.8 to 19.9 months to and second-line overall survival ranged from 5.1 to 26.5 months. No new safety signals were observed.

Conclusions:

Nivolumab may be considered as second-line therapy option after cabozantinib failure in selected metastatic collecting duct carcinoma patients.

"Collecting duct carcinoma of the kidney: diagnosis and implications for management"

Collecting duct carcinoma of the kidney is a rare and aggressive subtype of renal cell carcinoma (RCC) arising from the distal convoluted tubules. At the time of diagnosis, patients are more frequently symptomatic, with advanced locoregional stage, and have metastatic disease. The 2016 WHO Classification of Tumours of the Urinary System defined diagnostic criteria for this entity. However, the diagnostic features continue to evolve, with typical, but not entirely specific, histologic and immunophenotypic characteristics. In addition, the lack of consistent molecular alterations makes collecting duct carcinoma a diagnosis of exclusion, with historical cases being re-classified as fumarate hydratase deficient RCC, ALK rearranged RCC, renal medullary carcinoma or high-grade urothelial carcinoma. The rarity and poor prognosis of the tumor makes it difficult to reach consensus guidelines to guide therapy. In this manuscript we review the clinicopathologic features of collecting duct carcinoma including pathologic diagnostic criteria, molecular characteristics and differential diagnosis, and their possible implications for management.

[Collecting duct carcinoma]

Collecting duct carcinoma (Bellini duct carcinoma) is a very rare disease with poor prognosis. Primary tumor surgery is not advisable, even though it is the therapy of choice for suspected malignant space-occupying renal masses. Chemotherapy seems to be inferior to new therapeutic concepts based on single case reports. Immunotherapy with nivolumab and axitinib and additive radiotherapy significantly prolongs survival. At the same time, targeted therapy with cabozantinib seems promising. However, due to the short median survival and the side effects of these therapies, a purely supportive approach should be discussed. It should be decided with the patient whether a systemic therapy should be started or whether a palliative, supportive therapy concept offers more quality of life.

Update in collecting duct carcinoma: Current aspects of the clinical and molecular characterization of an orphan disease

Collecting duct renal cell carcinoma (cdRCC), which until recently was thought to arise from the collecting ducts of Bellini in the renal medulla, is a rare and aggressive type of non-clear renal cell carcinoma (ncRCC), accounting for 1% of all renal tumors and with nearly 50% of patients being diagnosed with Stage IV disease. The median overall survival in this setting is less than 12 months. Several regimens of chemotherapies had been used based on morphologic and cytogenetic similarities with urothelial cell carcinoma described previously, although the prognosis still remains poor. The use of targeted therapies also did not result in favorable outcomes. Recent works using NGS have highlighted genomic alterations in SETD2, CDKN2A, SMARCB1, and NF2. Moreover, transcriptomic studies have confirmed the differences between urothelial carcinoma and cdRCC, the possible true origin of this disease in the distal convoluted tubule (DCT), differentiating from other RCC (e.g., clear cell and papillary) that derive from the proximal convoluted tubule (PCT), and enrichment in immune cells that may harbor insights in novel treatment strategies with immunotherapy and target agents. In this review, we update the current aspects of the clinical, molecular characterization, and new targeted therapeutic options for Collecting duct carcinoma and highlight the future perspectives of treatment in this setting.

Efficacy of combination therapy with pembrolizumab and axitinib for metastatic renal collecting duct cell carcinoma: A report on two cases

Introduction

Immunotherapy‐based combinations have become the standard first‐line therapy for metastatic renal cell carcinoma. However, combined immunotherapy for renal collecting duct carcinoma had been reported, but its therapeutic efficacy had been unclear.

Case presentation

The first case was a 62‐year‐old man treated with pembrolizumab and axitinib for renal collecting duct carcinoma with multiple bone metastases. After 7 months, the primary and metastatic lesions shrunk and were evaluated as a partial response. The second case was a 71‐year‐old man treated with pembrolizumab and axitinib for renal collecting duct carcinoma with lymph node and lung metastases. After 9 months, the primary and metastatic lesions shrunk and were evaluated as a partial response. In both cases, the tumor cell expression of programmed death ligand‐1 was negative, and CD4⁺ and CD8⁺ cells were observed in the tumor.

Conclusion

Combined immunotherapy with pembrolizumab and axitinib may be effective for metastatic renal collecting duct carcinoma.

Mortality according to treatment in metastatic collecting duct renal cell carcinoma

INTRODUCTION

Controlled contemporary analyses of mortality in metastatic collecting duct renal cell carcinoma (mcdRCC) are unavailable. We addressed this knowledge gap and tested rates of treatment and associated mortality in patients with mcdRCC.

PATIENTS AND METHODS

Within Surveillance, Epidemiology, and End Results database (2004-2018), we identified 155 mcdRCC patients. Kaplan-Meier plots and Cox proportional hazards regression models tested the effect of treatment (cytoreductive nephrectomy [CN] alone vs. systemic therapy [ST] alone vs. combination of both CN + ST) on overall mortality (OM).

RESULTS

In the overall cohort (n = 155), 57 patients (37%) were treated with combination of both CN + ST, 46 (30%) underwent CN alone, 28 (18%) received ST alone, and 24 (15%) had none/unknown treatment. According to age categories (≤ 59 vs. 60-69 vs. ≥ 70 years), rates of combination of both CN + ST were 45% vs. 45% vs. 14%, respectively. CN alone was the most frequent type of treatment in patients aged ≥ 70 (50%). Median overall survival was 4.0 months for CN alone vs. 5.5 months for ST alone vs. 9.0 months for combination of both CN+ST. In multivariable Cox regression models, where CN alone was the referent, the use of ST alone and combination of both CN + ST were respectively associated with a HR of 0.74 (P = .3) and 0.43 (P < .001), after adjustment for all covariates.

CONCLUSIONS

In mcdRCC patients, concomitant use of CN and ST results in lowest mortality, followed by ST alone, and CN alone. In consequence combination of both CN + ST should be recommended whenever applicable.

Complete response to combination therapy using nivolumab and ipilimumab for metastatic, sarcomatoid collecting duct carcinoma presenting with high expression of programmed death-ligand 1: a case report

BACKGROUND

Collecting duct carcinoma and sarcomatoid renal cell carcinoma are tumors with poor prognosis. Immune checkpoint inhibitors have been established as the standard treatment for advanced renal cell carcinoma. Some cases of remission of collecting duct carcinoma and sarcomatoid renal cell carcinoma have been reported using immune checkpoint inhibitor interventions. Specifically, sarcomatoid renal cell carcinoma expresses high levels of programmed death-ligand 1, an immune checkpoint protein, and immune checkpoint inhibitors have been reported to be highly effective for treating sarcomatoid renal cell carcinoma.

CASE PRESENTATION

We describe the case of a 70-year-old Japanese male who underwent radical right nephrectomy for a right renal mass identified on computed tomography. The pathological examination demonstrated that the renal mass was urothelial carcinoma and collecting duct carcinoma with sarcomatoid changes, and programmed death-ligand 1 was highly expressed with a tumor proportion score of more than 10%. There was no evident submucosal connective tissue invasion in the urothelial carcinoma component, and collecting duct carcinoma was diagnosed as primary cancer. The tumor-node-metastasis classification was pT3aN0, venous invasion 1, lymphovascular invasion 0, and Fuhrman nuclear grade 4. Two months after the nephrectomy, multiple metastases were observed in both lungs, the right hilar lymph node, and the S6 segment of the right liver lobe. We initiated first-line combination therapy with nivolumab (240 mg, fixed dose) and ipilimumab (1 mg/kg). One day after administration, the patient developed drug-induced interstitial pneumonia, thus we applied steroid injections. After one administration of immunotherapy, the metastatic lesion showed complete response within 6 months, which was maintained after 3 years.

CONCLUSION

We report the first case of complete response to a single dose of combination therapy with nivolumab and ipilimumab for metastatic collecting duct carcinoma with sarcomatoid changes and high expression of programmed death-ligand 1. This case suggests high expectations for immune checkpoint inhibitors as treatment for sarcomatoid-transformed renal carcinoma tumors that express high levels of programmed death-ligand 1.

Metastatic Renal Medullary and Collecting Duct Carcinoma in the Era of Antiangiogenic and Immune Checkpoint Inhibitors: A Multicentric Retrospective Study

Collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are two rare subtypes of kidney cancer with a poor prognosis in the metastatic setting. Beyond first-line treatment, there are no standard-of-care therapies. This retrospective study assessed the efficacy of treatments after first-line chemotherapy in 57 patients with metastatic (m) CDC (n = 35) or RMC (n = 22) treated between 2010 and 2019 at 11 French centers. The median age was 53 years; overall, 60% (n = 34) of patients were metastatic at diagnosis. After a median follow-up of 13 months, the median overall survival was 12 (95% CI, 11−16) months. All patients received first-line platinum chemotherapy ± bevacizumab, with a median time to progression of 7.27 (95% CI, 7−100 months and an objective response rate (ORR) of 39% (95% CI, 26−52%). Patients received a median of two (1−5) treatment lines. Subsequent treatments included tyrosine kinase inhibitors (n = 12), chemotherapy (n = 34), and checkpoint inhibitors (n = 20), with ORR ranging 10−15% and disease control rates ranging 24−50%. The duration of response for all treatments was ~2 months. Notably, nine patients with CDC were still alive > two years after metastatic diagnosis. Beyond first-line therapy, treatments showed very low antitumor activity in mCDC/RMC. A better understanding of the biology of those rare tumors is urgently needed in order to identify potential targets.

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.

Characteristics and Treatment Challenges of Non-Clear Cell Renal Cell Carcinoma

Non-clear cell renal cell carcinomas (RCC) comprise several rare and poorly described diseases, often characterized by bad prognosis and with no standard treatments available. The gap in their clinical management is linked to the poor molecular characterization in handling the treatment of non clear-cell RCC with untailored therapies. Due to their rarity, non-clear RCC are in fact under-represented in prospective randomized trials. Thus, treatment choices are based on extrapolating results from clear cell RCC trials, retrospective data, or case reports. Over the last two decades, various options have been considered as the mainstay for the treatment of metastatic RCC (mRCC), including angiogenesis inhibitors, vascular endothelial growth factor receptor inhibitors, other tyrosine kinase inhibitors (TKIs), as well as MET inhibitors and mammalian targeting of rapamycin (mTOR) inhibitors. More recently, the therapeutic armamentarium has been enriched with immunotherapy, alone or in combination with targeted agents that have been shown to significantly improve outcomes of mRCC patients, if compared to TKI single-agent. It has been widely proven that non-clear cell RCC is a morphologically and clinically distinct entity from its clear cell counterpart but more knowledge about its biology is certainly needed. Histology-specific collaborative trials are in fact now emerging to investigate different treatments for non-clear cell RCC. This review summarizes pathogenetic mechanisms of non-clear cell RCC, the evolution of treatment paradigms over the last few decades, with a focus on immunotherapy-based trials, and future potential treatment options.

Integrative Transcriptomic Analysis Reveals Distinctive Molecular Traits and Novel Subtypes of Collecting Duct Carcinoma

Collecting duct carcinoma (CDC) is a rare and highly aggressive kidney cancer subtype with poor prognosis and no standard treatments. To date, only a few studies have examined the transcriptomic portrait of CDC. Through integration of multiple datasets, we compared CDC to normal tissue, upper-tract urothelial carcinomas, and other renal cancers, including clear cell, papillary, and chromophobe histologies. Association between CDC gene expression signatures and in vitro drug sensitivity data was evaluated using the Cancer Therapeutic Response Portal, Genomics of Drug Sensitivity in Cancer datasets, and connectivity map. We identified a CDC-specific gene signature that predicted in vitro sensitivity to different targeted agents and was associated to worse outcome in clear cell renal cell carcinoma. We showed that CDC are transcriptionally related to the principal cells of the collecting ducts providing evidence that this tumor originates from this normal kidney cell type. Finally, we proved that CDC is a molecularly heterogeneous disease composed of at least two subtypes distinguished by cell signaling, metabolic and immune-related alterations. Our findings elucidate the molecular features of CDC providing novel biological and clinical insights. The identification of distinct CDC subtypes and their transcriptomic traits provides the rationale for patient stratification and alternative therapeutic approaches.

Comprehensive genomic profiling of metastatic collecting duct carcinoma, renal medullary carcinoma, and clear cell renal cell carcinoma

INTRODUCTION AND OBJECTIVE

Unlike clear cell renal cell carcinoma (CCRCC), collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are rare tumors that progress rapidly and appear resistant to current systemic therapies. We queried comprehensive genomic profiling to uncover opportunities for targeted therapy and immunotherapy.

MATERIAL AND METHODS

DNA was extracted from 40 microns of formalin-fixed, paraffin-embedded specimen from relapsed, mCDC (n = 46), mRMC (n = 24), and refractory and metastatic (m) mCCRCC (n = 626). Comprehensive genomic profiling was performed, and Tumor mutational burden (TMB) and microsatellite instability (MSI) were calculated. We analyzed all classes of genomic alterations.

RESULTS

mCDC had 1.7 versus 2.7 genomic alterations/tumor in mCCRCC ( = 0.04). Mutations in VHL (P < 0.0001) and TSC1 (P = 0.04) were more frequent in mCCRCC. SMARCB1 (P < 0.0001), NF2 (P = 0.0007), RB1 (P = 0.02) and RET (P = 0.0003) alterations were more frequent in mCDC versus mCCRCC. No VHL alterations in mRMC and mCDC were identified. SMARCB1 genomic alterations were significantly more frequent in mRMC than mCDC (P = 0.0002), but were the most common alterations in both subtypes. Mutations to EGFR, RET, NF2, and TSC2 were more frequently identified in mCDC versus mRMC. The median TMB and MSI-High status was low with <1% of mCCRC, mCDC, and mRMC having ≥ 20 mut/Mb.

CONCLUSION

Genomic alteration patterns in mCDC and mRMC differ significantly from mCCRCC. Targeted therapies for mCDC and mRMC appear limited with rare opportunities to target alterations in receptor tyrosine kinase and MTOR pathways. Similarly, TMB and absence of MSI-High status in mCDC and mRMC suggest resistance to immunotherapies.

Assessment of HER2 Protein Overexpression and Gene Amplification in Renal Collecting Duct Carcinoma: Therapeutic Implication

Collecting duct carcinoma (CDC) is rare and aggressive histology of kidney cancers. Although different therapeutic approaches have been tested, the 2-year survival remains very poor. Since CDC exhibits overlapping features with urothelial carcinoma, the analysis of shared molecular alterations could provide new insights into the understanding of this rare disease and also therapeutic options. We collected 26 CDC cases, and we assessed HER2 protein expression by immunohistochemistry (IHC) and gene amplification by fluorescence in-situ hybridization (FISH) according to 2018 ASCO/CAP HER2-testing recommendations. Six out of twenty-six (23%) tumors showed HER2 positive staining. In particular, 3+ score was present in 2/6 cases (33%), 2+ in 3/6 cases (50%) and 1+ in 1/6 cases (17%). The 6 HER2+ tumors were also analyzed by FISH to assess gene copy number. One out of six CDC with IHC 3+ was also HER2 amplified, showing an average HER2 copy number ≥4.0 (10.85) and a HER2/CEP17 ratio ≥ (5.63), while the 5/6 cases were HER2 negative. Based on the 2018 ASCO/CAP guidelines overall, 2/26 CDC cases (8%) were HER2+. The present study provides evidence for testing, in future studies, HER2 to assess its clinical value as a novel target for the treatment of this highly malignant cancer.

Complete response to combination therapy with nivolumab and ipilimumab for metastatic collecting duct carcinoma of the kidney

Collecting duct carcinoma (CDC) of the kidney is a rare subtype of renal cell carcinoma (RCC) arising from the distal collecting tubules, characterized by an aggressive phenotype, unfavorable response to several types of systemic agent and a poor prognosis. Recently, treatments with immune checkpoint inhibitors have been widely performed for patients with metastatic RCC; however, no data are available regarding the impact of first-line combination therapy with nivolumab and ipilimumab on metastatic CDC. Here, we report a CDC patient with multiple lymph node metastases who underwent cytoreductive open nephrectomy and subsequently, received nivolumab and ipilimumab therapy. Following four courses of this combined therapy, all nodal metastases had shrunk to < 1 cm in diameter, and thus this patient was judged to show a complete response (CR). To our knowledge, this is the first reported case of a patient with metastatic CDC achieving a CR to combined treatment with nivolumab and ipilimumab, which could be a promising first-line therapy against metastatic CDC.

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.