Prognostic impact of non-clear cell histology on recurrence and cancer-free survival in renal cell carcinoma: a time-to-event analysis.

Abstract

Objectives: To determine risk factors associated with the recurrence of renal cell carcinoma (RCC), either local recurrence or distant metastasis, and to characterize a contemporary cohort of patients with non-clear RCC (ncRCC) in terms of cancer-free survival (CFS) and time to such recurrence.

Methods: A retrospective review of prospectively collected data was performed for consecutive patients undergoing partial and radical nephrectomy at a tertiary care center in Saudi Arabia. Data collection included patients and tumor characteristics, perioperative parameters, and histopathological patterns. Multivariate logistic regression determined the predictors of tumor recurrence while Kaplan-Meier analyses assessed CFS and the time to recurrence.

Results: A total of 214 patients were analyzed, including 150 (70.1%) ccRCC and 64 (29.9%) ncRCC, with a mean age of 54.8 ± 1.7 years and tumor size of 6.9 ± 0.7 (1.2-24.0) cm. After a median follow-up of 47.6 ± 12.4 months, 32(14.9%) patients developed recurrence. In multivariate regression, tumor recurrence was significantly associated with tumors ≥ 6.9 cm [aOR (95% CI): 2.85 (1.67-5.43)], renal vein or inferior vena cava vascular invasion [aOR: 1.92 (1.32-4.21)], pathological staging ≥ 2b [aOR: 2.66 (1.95-5.34)] (8th edition of the AJCC Cancer Staging Manual, 2017), and positive lymph nodes in the specimen [aOR: 3.28 (2.97-5.15)]. The recurrence-free status was 85% at 5 years, while the mean time to recurrence was 9 (6-42) months. Patients with ncRCC had comparable recurrence rates to those with ccRCC (12.5% vs. 16.0% p = 0.64), respectively. The 5-year CFS was 62.8% (95% CI: 54.2-68.7) for ncRCC and 76.8% (95% CI: 67.4-87.2) for ccRCC (p = 0.77).

Conclusion: Compared to clear cell RCC, patients with non-clear cell RCC showed no significant differences in demographic, tumor, or perioperative characteristics. In our cohort, both histopathological subtypes demonstrated comparable recurrence rates and 5-year cancer-free survival.