MP64-05 BILATERAL MULTIFOCAL PAPILLARY TYPE I RENAL CELL CARCINOMA: CLINCAL CHARACTERISTICS AND ASOCIATION WITH CHRONIC RENAL INSUFFICIENCY

Abstract

INTRODUCTION AND OBJECTIVES: Bilateral multifocal (BMF) papillary type I renal cell carcinoma (RCC) is commonly associated with Hereditary Papillary Renal Cell Carcinoma (HPRCC) with mutation of the MET proto-oncogene, however the sporadic (non-familial) BMF papillary type I RCC is far more prevalent. These patients with BMF RCC are at risk for multiple surgeries, progressive loss of renal tissue and chronic renal insufficiency. Here we describe the histologic and clinical phenotype of a population of patients with BMF papillary type I RCC that are distinct from the HPRC population. METHODS: From 1996 to 2013, patients who were evaluated at the National Cancer Institute and were diagnosed with BMF RCC on cross sectional imaging were identified. Patients who tested negative for MET proto-oncogene mutation, who had a pathologic diagnosis of papillary type I were included. Phenotypic manifestations and surgical management prior to presentation were analyzed. RESULTS: 61 patients with an average age of 54.3 years were identified. Fifty seven (93%) of these patients were male. Additionally, a disproportionate number (22, 36%) of these patients were of African American descent. Nineteen (31%), five (8%), four (6.6%) and ten (16.4%) patients underwent prior unilateral radical nephrectomy, unilateral partial nephrectomy, unilateral radical nephrectomy plus partial nephrectomy and bilateral partial nephrectomies respectively. On presentation the average largest tumor diameter was 3.7 cm, serum creatinine was 1.48 mg/dl and eGFR was 62.6 ml/min. There was no difference between the eGFR (62.09 ml/min and 63.19 ml/min) or serum creatinine (1.49 mg/dl and 1.47 mg/dl) in African American and Caucasian patients respectively. This population had an average of 3 and 3.4 right and left sided tumors respectively, and many patients also had numerous cysts in both kidneys. Four patients (6.6%) were also found to have had metastatic disease on presentation. Three patients were found at diagnosis to have pulmonary and mediastinal metastatic disease. CONCLUSIONS: BMF papillary type I RCC represents a novel entity which disproportionally affects African Americans. Most of these patients have had prior surgeries and often present with Stage II chronic kidney disease, putting them at significant risk for further renal deterioration and insufficiency. As a small percentage of these patients with BMF papillary type I will present with metastatic disease, active surveillance until the largest renal tumor reaches 3 cm is recommended.