Propensity score-matched comparison of survival outcomes between clear cell and non-clear cell renal cell carcinoma in cT1N0M0 disease.

BACKGROUND

Non-clear cell renal cell carcinoma (nccRCC) is a rare and heterogeneous group of tumors, and data regarding its prognosis remain limited. This study primarily aimed to compare survival outcomes between clear cell RCC (ccRCC) and nccRCC, limited to papillary and chromophobe RCC, using propensity score matching (PSM). A secondary analysis evaluated prognostic differences among histological subtypes of nccRCC.

METHODS

We retrospectively reviewed patients who underwent curative surgery for non-metastatic RCC between 2001 and 2023. Patients with cT1N0M0 ccRCC and nccRCC (papillary and chromophobe RCC) were matched at a 2:1 ratio using PSM. Recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were compared overall and according to surgical procedure. A secondary analysis compared survival outcomes among histological subtypes of nccRCC.

RESULTS

The matched cohort included 100 patients with ccRCC and 50 with nccRCC. Five-year RFS, CSS, and OS were comparable between the groups (94.2% vs. 95.3%, P = 0.934; 100% vs. 95.3%, P = 0.564; and 96.9% vs. 100%, P = 0.573, respectively). Similar findings were observed in both radical and partial nephrectomy subgroups. In the secondary analysis, survival outcomes varied according to histological subtype among patients with nccRCC.

CONCLUSIONS

After adjustment for baseline characteristics, including surgical modality, survival outcomes were comparable between cT1N0M0 ccRCC and papillary or chromophobe RCC. Surgical modality did not appear to modify these outcomes. Prognosis differed according to histological subtype among patients with nccRCC, supporting individualized treatment strategies and follow-up protocols.