Risk of Isolated Metastatic Disease Outside the Abdomen is Low in Ct1a Renal Cancer: A Retrospective Analysis of a Large Cohort from the Scottish Renal Cancer Consortium

Objectives: Chest computed tomography (CT) is recommended by the European Association of Urology guidelines as part of the evaluation of patients presenting with renal tumours. There are no direct recommendations for the use of computed tomography (CT) pelvis, but this is often included routinely in the assessment for metastatic disease. The incidence of metastatic disease in cT1a renal cell carcinoma (RCC) is low. Predictive algorithms may be able to guide the selective use of chest CT in the pre-operative evaluation of patients. We sought primarily to assess the clinical utility of these algorithms in predicting lung and pelvic metastases in a national cohort of purely cT1a tumours. Patients and Methods: Patients with sporadic, unilateral cT1a renal tumours diagnosed between January 2012 and December 2017 were identified from a prospectively collected national database. Patient clinico-pathological parameters and treatment type were recorded. Details on clinical presentation and bloods at diagnosis were taken from local electronic records retrospectively. Differences between those with and without metastatic disease were assessed. Results: Of the total 696 patients, 7 (1.0%) patients had metastatic disease exclusively outside the abdomen. Indeterminate lung lesions were present in 114 (16.6%) patients, with 2 (1.8%) progressing to presumed metastatic disease. Patients with metastatic disease were more likely to be anaemic than those without metastatic disease (85.7% and 25.7%, respectively, p = 0.020). Conclusion: Metastatic disease at presentation with cT1a renal cancer was uncommon in our national multi-centre series, with limited impact on clinical management. Patients with cT1a without intra-abdominal metastatic disease could safely avoid CT chest or pelvic CT at diagnosis, with benefits in terms of radiation exposure and resource utilisation. Level of evidence: 3.