What's known on the subject? and What does the study add?
- Small, organ-confined renal cell carcinoma (RCC) generally has favourable pathological characteristics and a good prognosis. However, late recurrence is a known characteristic of the biological behaviour of RCC and no consensus has been established for surveillance protocols from 5 years after radical or partial nephrectomy.
- In the present study with long-term follow-up of patients with small RCCs, 18 of 172 patients (10.5%) with pT1a RCC developed recurrence and eight of these (4.7%) died from cancer. Patients with microvascular invasion had a higher risk for cancer death than those without (P < 0.001, Log-rank test). Therefore long-term follow-up is required after surgery, particularly when the disease has microvascular invasion.
- To identify the long-term clinical course of small, organ-confined renal cell carcinoma (RCC).
- To detect the risk factors of recurrence and of cancer death in small RCC.
Patients and Methods
- Retrospectively reviewed 172 patients who were pathologically diagnosed as having pT1a RCC without metastasis at our institution from 1980 to 2005.
- All pathology slides were re-reviewed by a single experienced pathologist.
- Associations of microvascular invasion (MVI), development of metastasis, and cancer death were evaluated using Cox proportional hazards analysis.
- During a median (range) follow-up of 104.5 (8–308) months, 18 patients (10.5%) developed progression and eight patients (4.7%) died from cancer.
- Kaplan–Meier curves showed higher cancer-specific survival (CSS) in patients without MVI (P < 0.001).
- In multivariate analysis, MVI was the only factor that reached statistical significance (P = 0.006).
- The 10-year CSS rates were 85.1% and 96.5% in patients with and without MVI, respectively.
- Patients with MVI have worse survival than those without MVI.
- This suggests that long-term follow-up of patients with small RCCs is needed because of the risk of recurrence and cancer death even 10 years after surgery, particularly when the disease has apparent MVI.