In this study, the investigators profiled plasma glycosaminoglycans (GAGs) in a retrospective consecutive series of patients with a radiographic finding of renal mass referred to primary surgery for renal cell carcinoma (RCC). A control group was formed by measuring plasma GAGs in healthy volunteers. The primary endpoints were the specificity and sensitivity of plasma GAGs in the detection of early stage RCC in pre-surgical samples versus healthy individuals. The investigators further analyzed how plasma GAGs varied according to stage, grade, RCC histology, other renal masses, and after surgery. Finally, the investigators estimated whether plasma GAGs could be used for prediction and surveillance of RCC recurrence.

Inclusion Criteria:

• Patients with radiographic finding of renal mass referred to primary surgery;
• Healthy volunteers without any history of malignancy.

Exclusion Criteria:

• No records on date of surgery;
• A pre-operative sample was obtained 50 days or earlier with respect to the date of surgery; - Absence of pre-operative samples following filtering out outliers or laboratory assay failures.

Patients with pathologically confirmed diagnosis of RCC treated with surgical resection of the tumor