Pathologic upstaging after laparoscopic radical nephrectomy.

OBJECTIVE: Accurate tumor staging in renal cancer is critical for prognostic projections, follow-up schedules, clinical trials and potential systemic therapies. We studied patients undergoing laparoscopic radical nephrectomy (LRN) to determine the extent of upstaging on histopathology evaluation and correlated the clinical and pathology staging to determine the factors responsible for upstaging.

PATIENTS AND METHODS: A retrospective review of patients undergoing LRN for renal cell cancer was performed. Clinical staging was determined by CT/MRI scan and/or related preoperative work up (using AJCC TNM staging criteria). Histopathology reports were studied in to determine the p-stage. Lymph node (LN) status was evaluated with attention to number and positivity of LNs in the specimen. Pathologic features that dictated upstaging were analyzed. The factors responsible for pathologic upstaging were analyzed. Statistical analysis was performed using JMP 5.0.12 software; comparisons were done using chi square or Fisher exact test.

RESULTS: One hundred twenty three patients qualified for the study; mean age was 62.14+/-13.6 years, M:F ratio was 60:63 and mean tumor size of 5.3+/-2.0 cm. Clinical versus pathologic T stage distribution was T1a=41:37, T1b=43:31, T2=25:12, T3a=11:31, T3b=3:10 and T4=0:2. A total 38/123 (31%) patients were upstaged following histopathology examination. Upstaging was due to change in tumor size in 12, renal sinus fat involvement in 8, renal or adrenal vein involvement in 14, focal perirenal fat involvement in 6, and focal renal capsule penetration in 4 patients. Fifty two patients had LNs in the specimen with 19 (16%) patients had 2 or more lymph nodes and 5 had positive LNs. Mean tumor size was 5.3+/-2 cms at clinical, and 5.0+/-2.6 cms at pathology staging (P=NS). 5 patients had LN metastasis detected with tumor size of 5.5, 5.6, 6.8, and 7.2 cms in diameter, and one patient with LN metastasis was T1a stage (3.2 cm). Renal vein/inferior venal cava/adrenal vein was involved in 14 patients, adrenal was involved in 21 patients and renal sinus was involved in 19/123 patients.

CONCLUSIONS: Pathologic upstaging of malignant renal neoplasms occurred in about 31% of patients following LRN. Down staging was less common and mean tumor size does not significantly change.