非小細胞腎細胞がんの治療パラダイムの更新

Non - clear cell renal cell carcinoma (nccRCC) encompasses a heterogeneous group of rare malignancies, representing approximately 20-25% of all renal cancers. Unlike clear cell RCC (ccRCC), these subtypes - papillary, chromophobe, collecting duct, translocation, molecularly defined variants and others - display distinct biological behaviors, genetic profiles, and therapeutic sensitivities, which preclude a uniform treatment approach.

This review provides an updated overview of systemic therapy for nccRCC, integrating evidence from prospective trials, retrospective series, and translational research. For most of these histologies, immune checkpoint inhibitor (ICI) - based combinations (e.g. pembrolizumab - lenvatinib, nivolumab - cabozantinib or nivolumab-ipilimumab) have demonstrated the best activity. In chromophobe RCC (chRCC), also mechanistic target of rapamycin (mTOR) inhibition appears particularly relevant, whereas in collecting duct carcinoma and renal medullary carcinoma platinum-based chemotherapy continue to have an important role, with cabozantinib showing encouraging results. Novel biomarker-driven approaches are emerging for selected molecular subsets.

Although remarkable progress has been achieved, the optimal therapeutic strategy for nccRCC remains undefined. Future efforts should focus on histology- and biomarker-driven clinical trials, molecular stratification, to optimize efficacy across subtypes. International collaboration is crucial to overcome the challenges posed by the rarity and biological heterogeneity of these tumors.