Immunotherapy treatment for sarcomatoid renal cell carcinoma: case report and literature review.

Introduction: Sarcomatoid renal cell carcinoma (SRCC) is clinically rare, accounting for ~1.0-1.5% of renal parenchymal tumors. Although the concept of SRCC was proposed in 1968, the molecular mechanisms and immunological characteristics of sarcomatoid changes remain unclear. In the era of targeted therapy, the overall survival (OS) of patients with SRCC is typically less than 12 months. Case presentation: This article reports a case of SRCC in an 81-year-old male. Progression-free survival (PFS) was as long as 25 months and OS was 30 months after immunotherapy and the effect was significant. This is the first report of successful use toripalimab in the treatment of SRCC. Clinical discussion: SRCC is a rare type of renal cancer with no obvious specific clinical manifestations or imaging findings, and the diagnosis of the disease is based on pathological examinations. SRCC has a high degree of malignancy, progresses rapidly, and has a poor prognosis. The effect of traditional treatment is limited, and immune checkpoint inhibitors may have therapeutic potential. Conclusions: Toripalimab may be effective and further exploration is anticipated to advance a new period of SRCC.