Presentation Authors: Naveen Krishnan*, Jay Sulek, Indianapolis, IN, Caleb Cooper, Chicago, IL, Isamu Tachiabana, Liang Cheng, Chandru Sundaram, Indianapolis, IN
Introduction: The classification of unclassified renal cell carcinoma (URCC) includes morphologically distinct tumors that are generally high grade with unrecognizable cell types or pure sarcomatoid histology without typical renal cell epithelial components. In recent contemporary series, this category of tumors is remarkably heterogeneous in histopathology and genetic features. The aim of our study is to compare stage-matched patient cohorts with clear cell renal cell carcinoma (ccRCC) and URCC in terms of demographics, risk of recurrence, and overall and disease-specific survival rates.
Methods: We conducted a single institutional retrospective cohort study analyzing our renal database which captured cases between August 2001 and July 2017. Information obtained through hospital, supplemental state, and obituary records. We investigated patient demographic data, as well as rate of recurrence, and overall and disease-specific survival.
Results: There were 119 cases of unclassified renal cell carcinoma between August 2001 and July 2017 or 6.15% of all cases (Table 1). At the time of nephrectomy, 9.48% of patients had evidence of metastasis. The median length of follow up was 20 months. The overall and disease specific mortality was 35.3% and 16.4%, respectively. No statistical difference in overall or disease-specific survival was seen between stage matched patients with ccRCC and URCC (Figures 1 and 2).
Conclusions: To our knowledge, this is the largest cohort of patients with URCC with clinical follow up. The incidence of URCC among all patients in this cohort was greater than previously reported. Patients with URCC did not have a worse overall or disease-specific survival outcomes