|Title: ||Should the pT2 tumor classification for renal cell carcinoma be subdivided according to tumor size?|
|Authors: ||Van Poppel, Hendrik # ×|
|Issue Date: ||Dec-2007 |
|Publisher: ||NPG New York|
|Series Title: ||Nature clinical practice urology vol:4 issue:12 pages:648-649|
The tumor-node-metastasis (TNM) staging system for renal cell carcinoma (RCC) classifies all tumors >7 cm (pT2) together, and few studies have assessed the prognostic implications of tumor size within the pT2 group.
The objective of this study was to assess whether subdividing the RCC pT2 stage into two subgroups according to tumor size could increase the prognostic accuracy of the TNM staging system.
DESIGN AND INTERVENTION
This study recruited patients from nine different centers in Austria, France, Germany, Italy, and the US between 1984 and 2005. Patients were included in the study if they
underwent surgery for unilateral RCC, had negative surgical margins, and had not received adjuvant therapy postoperatively. At initial presentation, patient records
were reviewed to determine the Eastern Cooperative Oncology Group performance status (ECOG-PS). Assessment before surgery included radiographic evaluation (chest X-ray
or chest CT, and MRI or CT of the abdomen and pelvis), measurement of serum electrolytes and determination of liver function. After surgery, nephrectomy specimens were pathologically assessed by a group of pathologists
at each institution; histology (according to the Heidelberg classification), tumor grading (according to the Fuhrman grading system), and TNM stage were determined. Tumor size
was also recorded.
The primary outcome measure for this study was disease-specific survival.
The trial included 706 patients, of whom 685 underwent radical nephrectomy and 21 underwent partial nephrectomy. The median patient age was 58.2 ± 12.8 years. Overall, the mean tumor size for all patients was 9.8 ± 2.4 cm.
For patients with metastatic disease, mean tumor size was 10.2 ± 2.6 cm, and for patients with nonmetastatic cancer it was 9.7 ± 2.4 cm; tumor size was significantly associated with metastases (risk ratio 1.08, 95% CI 1.002–1.16, P = 0.04). During a median follow-up period of
2 years, 187 patients died of RCC; tumor size was also significantly associated with diseasespecific survival (hazard ratio 1.11, 95% CI 1.05–1.17, P <0.001). Tree-based recursive partitioning was performed, which identified
11 cm as an ideal cutoff point for dividing two subgroups in the pT2 stage. In total, 556 patients had a tumor smaller than 11 cm, and 150 had a tumor larger than 11 cm. Patients with a tumor <11 cm had 5-year and 10-year
survival rates of 73% and 65%, respectively, compared with patients with a tumor >11 cm who had 5-year and 10-year survival rates of 57% and 49%, respectively. The incidence
of metastasis and lymph node involvement was higher in patients with tumors >11 cm than patients with tumors <11 cm, whereas histological subtype, ECOG-PS and Fuhrman grade
were similar in both the <11 cm and >11 cm groups. On multivariate Cox regression, tumor size, metastasis stage, ECOG-PS and Fuhrman grade were independent prognostic factors for disease-specific survival.
Introduction of a pT2a subgroup (<11 cm) and a pT2b subgroup (>11 cm) to the TNM staging system for RCC will improve prognostic accuracy.
|Publication status: ||published|
|KU Leuven publication type: ||IT|
|Appears in Collections:||Urology Section (-)|