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

The incidence, pathogenesis, and management of non-clear cell renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and is divided into two distinct subtypes, clear cell renal cell carcinoma (ccRCC) and non-clear cell renal cell carcinoma (nccRCC). Although many treatments exist for RCC, these are largely based on clinical trials performed in ccRCC and there are limited studies on the management of nccRCC. Non-clear cell RCC consists of multiple histological subtypes: papillary, chromophobe, translocation, medullary, collecting duct, unclassified, and other rare histologies. Due to variations in pathogenesis and therapeutic response, therapy should be tailored to specific variant histologies. For patients with localized nccRCC, surgical resection remains the gold standard. In the metastatic setting, the standard of care has yet to be clearly defined, and most guidelines recommend clinical trial participation. General therapeutic options include immunotherapy, either as monotherapy or in combination, targeted therapies such as vascular endothelial growth factor tyrosine kinase inhibitors and MET inhibitors, and chemotherapy in certain subtypes. Here we present a review of the incidence and pathogenesis of the various subtypes, as well as available clinical data to support therapeutic recommendations for these subtypes. We also highlight currently available clinical trials in nccRCC and future directions in investigating novel treatment modalities tailored to patients with variant histology.

[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.

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.