Dr Westbrook on the Evolving Understanding of Non–Clear Cell RCC Subtypes

Thomas Westbrook, MD, hematologist/medical oncologist, assistant professor, Department of Internal Medicine, Rush University Medical Center, discusses the evolving understanding of non–clear cell renal cell carcinoma (nccRCC) and implications for clinical practice.

nccRCC represents a heterogeneous group of renal cancers, Westbrook begins. Non–clear cell indicates the absence of clear cell histology, but the category encompasses dozens of distinct subtypes. This classification does not denote a single disease, but rather a collection of diverse entities, he emphasizes.

Advancements in molecular pathology have been pivotal in distinguishing these subtypes, Westbrook explains. As molecular diagnostic tools improve, the ability to identify the unique characteristics of each renal carcinoma subtype has expanded. This deeper understanding is essential for tailoring therapeutic approaches to the individual patient, he adds. Westbrook also highlights that molecularly defined subtypes of renal cell carcinoma (RCC) are increasingly being recognized as separate entities, reflecting the growing importance of molecular pathology in the diagnostic process for suspected renal cancers.

Updates to the World Health Organization (WHO) 2022 classification of kidney tumors have further refined this evolving landscape, Westbrook notes. The major update to the WHO classification of renal tumors includes the distinction between clear cell RCC, papillary RCC, oncolytic and chromophobe RCC, collecting duct RCC, as well as the addition of other renal tumors and molecularly defined RCC as distinct subtypes.

Westbrook concludes that nccRCC is not a single diagnosis but a spectrum of distinct subtypes, each with its own molecular characteristics. Continued research into defining these molecular subtypes will be useful for guiding future therapeutic decisions and improving outcomes for patients with this complex and difficult-to-treat disease.