Re-evaluation of the Tumour-Node-Metastasis staging of locally advanced renal cortical tumours: absolute size (T2) is more significant than renal capsular invasion (T3a).
Authors from Iowa City report on the incidence of RCC; they compared the rate of these tumours at autopsy and felt that the decrease found was a result of better antemortem detection, and an increase with time in the frequency of clinically detected renal cancer. A study from New York attempted to determine whether size, or transcapsular extension irrespective of size, was more likely to produce an adverse outcome. They analysed their database of 717 such tumours between 1988 and 2002, and found that absolute tumour size was the more significant of the two findings.


OBJECTIVE
To determine which factor was more predictive of adverse outcome in our institutional experience with T2N0M0 and T3N0M0 renal cortical tumours (RCTs) treated surgically, as the current Tumour-Node-Metastasis (TNM) staging system for RCTs differentiates between tumours of >7.0 cm but confined to the renal capsule (T2) and tumours that extend through the renal capsule regardless of size (T3a).


METHODS
We analysed our institutional database of surgical urological oncology for all patients with T2N0M0 and T3aN0M0 RCT treated with partial or radical nephrectomy from 1988 to 2002. All patients with preoperative metastasis, bilateral or multifocal tumours, nonsporadic disease or benign histology were excluded from analysis. A follow-up of > or = 6 months from the time of surgery was required for inclusion. Primary outcomes included local and distant recurrence, and death.


RESULTS
In all, 717 patients had a partial or radical nephrectomy for RCT during the study period. After exclusion criteria were applied, 21 patients with T2N0M0 and 97 with T3aN0M0 tumours were eligible; the median (mean, range) age was 63 (16.6-88.3) years and follow-up 30.5 (40.8, 6-162) months. The estimated 5-year disease-free survival was 68% and 85% for T2N0M0 and T3aN0M0 RCT, respectively (P = 0.002). The 5-year disease-specific survival was 81% and 94% for the T2N0M0 and T3aN0M0 groups, respectively (P = 0.085).


CONCLUSIONS
Patients with T3aN0M0 tumours appear to have better disease-free and disease-specific survival than those with T2N0M0 disease, which suggests that tumour invasion through the renal capsule is not as significant as the absolute tumour size.
Murphy
Alana M
AM
Department of Urology, Columbia University Medical Center, 161 Fort Washington Avenue, 11th Floor, New York, NY 10032, USA.
Gilbert
Scott M
SM
Katz
Aaron E
AE
Goluboff
Erik T
ET
Sawczuk
Ihor S
IS
Olsson
Carl A
CA
Benson
Mitchell C
MC
McKiernan
James M
JM
D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007672:Kidney Cortex; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging