Long-term outcome of small, organ-confined renal cell carcinoma (RCC) is not always favourable.
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.


OBJECTIVE
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.


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.


RESULTS
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.


CONCLUSIONS
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.
Department of Urology, Sapporo Medical University School of Medicine, Sapporo, Japan.
Tetsuya
T
Shindo
Naoya
N
Masumori
Ko
K
Kobayashi
Fumimasa
F
Fukuta
Megumi
M
Hirobe
Akiko
A
Tonooka
Tadashi
T
Hasegawa
Hiroshi
H
Kitamura
Taiji
T
Tsukamoto
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000401:mortality; D009929:Organ Size; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies