Renal Cell Carcinoma in the Solitary Kidney: An Analysis of Complications and Outcome After Nephron Sparing Surgery

Abstract

Purpose: We evaluated surgical techniques, pathological features and extended outcomes in patients with renal cell carcinoma in a solitary kidney treated with surgical excision. Materials and Methods: Between 1970 and 1998, 76 patients underwent nephron sparing surgery for sporadic renal cell carcinoma in a solitary kidney, including 63 with tissue specimens available for pathological review who comprised the cohort. Six (9.5%) patients had a congenitally absent kidney and 57 (90.5%) had previously undergone contralateral nephrectomy for renal cell carcinoma. The clinical and pathological features examined were patient age at nephron sparing surgery, sex, type of nephron sparing surgery (enucleation, partial nephrectomy or ex vivo resection), tumor size, nuclear grade, histological subtype and 1997 tumor stage. Overall cancer specific, local recurrence-free and metastasis-free survival as well as early (within 30 days of nephron sparing surgery) and late (30 days to 1 year after nephron sparing surgery) complications were assessed. Univariate and multivariate analyses were done to test for the associations of clinical and pathological features with outcome. Results: Most patients were treated with enucleation (36.5%), standard partial nephrectomy (38.1%) or the 2 procedures (11.1%) and in 8 (12.7%) ex vivo tumor resection was done. The renal cell carcinoma histological subtypes were clear cell in 82.5% of cases, papillary in 15.9% and chromophobe in 1.6%. Grade was 1 to 3 in 10 (15.9%), 42 (66.7%) and 10 (15.9%) tumors, respectively. At 5 and 10 years the overall survival rate was 74.7% and 45.8%, the cancer specific survival rate was 80.7% and 63.7%, the local recurrence-free survival rate was 89.2% and 80.3%, and the metastasis-free survival rate was 69% and 50.4%, respectively. Tumor stage and nuclear grade were significantly associated with death from any cause, death from renal cell carcinoma and distant metastases on multivariate analysis. Notably no patient with papillary or chromophobe renal cell carcinoma died of renal cell carcinoma, or had recurrence or metastasis. The type of nephron sparing surgery was not significantly associated with outcome, although there were too few patients with recurrence to assess the association of the type of nephron sparing surgery with local recurrence. The most common early complication was acute renal failure in 12.7% of cases, while the most common late complications were proteinuria in 15.9% and renal insufficiency in 12.7%. Conclusions: The 1997 tumor stage and nuclear grade were significant predictors of death from any cause, death from renal cell carcinoma and distant metastases in patients treated with nephron sparing surgery for renal cell carcinoma involving a solitary kidney. Nephron sparing surgery in a solitary kidney can be performed safely and with minimal morbidity.