Characteristics and outcomes of T1a renal cell carcinoma presenting with metastasis.

Abstract

734 Background: T1a renal cell carcinoma (RCC) is associated with excellent cure rates. However, a small fraction present with metastasis. We sought to determine the clinical characteristics, variables associated with synchronous metastasis, and survival outcomes in patients with pT1a and cT1a RCC using the National Cancer Database (NCDB). We secondarily evaluated whether surgery impacted risk of all cause mortality in cT1a RCC with synchronous lung and bone metastasis. Methods: From 2004 to 2019, all cases of RCC in patients age ≥18 were extracted from NCDB. pT1a and cT1a RCC were characterized as those 1) with no metastasis at diagnosis, 2) with synchronous metastasis [pT1aNxM1 at diagnosis]. Impact of surgery on all cause mortality was not evaluated for cT1a with synchronous metastasis to liver and brain due to low sample sizes. Results: The table describes selected characteristics of the cohorts. On multivariable logistic regression, diagnosis of pT1a with synchronous metastasis was associated with age (OR 1.02), male sex (OR 1.64), tumor size (OR 1.84), cN1 (OR 1.08), sarcomatoid (OR 5.50), tumor grade (OR 2.84) (p<0.005 for these variables); and inversely with diagnosis in 2016-2019 (OR 0.66, p=0.044) and papillary histology (OR 0.45, p<0.001). On multivariable Cox regression of the cT1a cohort, ACM was associated with Charlson score (HR 1.50, p<0.001), metastasis to >1 site (HR 2.48, p=0.032), and inversely with radical (HR 0.42, p<0.001) and partial nephrectomy (HR 0.31, p<0.001). In cT1a with lung metastasis, partial (HR 0.06, p=0.049) and radical nephrectomy (HR 0.17, p=0.006) was inversely associated with ACM, while surgery of distant site was not. In cT1a with bone metastasis, partial (HR 0.21, p<0.001) and radical nephrectomy (HR 0.32, p<0.001) were the only variables inversely associated with ACM. 5-year overall survival for pT1a with synchronous metastasis is 39.4%; for cT1a with synchronous metastasis is 20.9%. Conclusions: Known prognostic features were associated with synchronous metastasis in T1a RCC. Surgical resection of primary site may impact risk of all cause mortality in select cases of synchronous metastatic disease. [Table: see text]