Localised non-metastatic sarcomatoid renal cell carcinoma: a 31-year externally verified study

Area of Science:

• Urology
• Oncology
• Pathology

Background:

• Limited research exists on localized sarcomatoid renal cell carcinoma (sRCC) outcomes.
• Most studies focus on advanced or metastatic sRCC.
• Understanding sRCC in localized disease is crucial for treatment strategies.

Purpose of the Study:

• To compare post-nephrectomy outcomes between localized sRCC and Grade 4 non-sRCC.
• To identify predictors of cancer-specific survival (CSS) in localized sRCC.
• To evaluate the impact of sarcomatoid features on localized renal cell carcinoma (RCC) prognosis.

Main Methods:

• Retrospective analysis of 564 patients undergoing nephrectomy for localized sRCC or Grade 4 non-sRCC.
• Kaplan-Meier analysis for CSS, overall survival (OS), and recurrence-free survival.
• Cox regression to identify predictors of CSS, with external validation using ASSURE trial data.

Main Results:

• sRCC demonstrated significantly worse CSS and OS compared to Grade 4 non-sRCC (P < 0.001).
• Even pT1 sRCC had worse CSS than pT3 Grade 4 non-sRCC.
• Negative CSS predictors included sarcomatoid features, non-clear cell histology, positive margins, higher pathological stage, and minimally invasive surgery (MIS).

Conclusions:

• Localized sRCC is an aggressive variant with poorer CSS than Grade 4 non-sRCC across all stages.
• Positive margins, higher pathological stage, MIS, and non-clear cell histology are negative prognostic factors.
• Vigilant surveillance and consideration for adjuvant therapy trials are recommended for localized sRCC.