Liver Metastases of Unknown Primary Renal Cell Carcinoma Treated With Immune Checkpoint Inhibitors Plus Tyrosine Kinase Inhibitors: A Case Report and Literature Review.

BACKGROUND/AIM: Renal cell carcinoma (RCC) constitutes approximately 3% of all cancers. More than 60% of RCCs are detected incidentally; one-third of patients present with regional or distant metastases, and another 20-40% of patients develop metastases after radical nephrectomy. RCC can metastasize to any organ. In contrast, metastatic RCC (mRCC) without evidence of a primary tumor is extremely rare, with only a few reported cases. CASE REPORT: We present a case of mRCC that initially presented with multiple liver and lymph node metastases but no primary renal lesion. An impressive response to treatment was achieved with a combination of immune checkpoint inhibitors and tyrosine kinase inhibitors. A clinical, radiological, and pathological diagnostic strategy, particularly in the context of a multidisciplinary team, are crucial for reaching a definitive diagnosis. This approach allows to select the appropriate treatment, making a huge difference for a mRCC due to its resistance to standard chemotherapy. CONCLUSION: There are currently no guidelines available for mRCC without primary tumor. Nevertheless, a combination of TKI and immunotherapy could be the optimal first-line treatment if systemic therapy is required.

Case report: Complete pathologic response with first-line immunotherapy combination in a young adult with massive liver dissemination of mismatch repair-deficient metastatic colorectal cancer: Immunological and molecular profiling.

The current level of evidence for immunotherapy in previously untreated microsatellite unstable metastatic colorectal cancer is based on recent pieces of evidence of few studies that demonstrated durable response and clinical benefit, in terms of objective response rate, disease control rate, and progression-free survival in this subgroup of patients. On the basis of combinatorial immunotherapy with nivolumab plus ipilimumab, we report the exceptional case of a complete pathological response in a 21-year-old woman presenting a clinically aggressive stage IV colorectal cancer with massive nodal and liver involvement. Extensive molecular analyses based on whole genome next-generation DNA sequencing, RNA sequencing, fluorescent multiplex immunohistochemistry, and flow cytometry provided a detailed description of tumoral and immunological characteristics of this noteworthy clinical case.