ORLANDO—Researchers have identified preoperative predictors of malignancy and unfavorable pathology in patients with clinical T1a renal tumors undergoing partial nephrectomy, according to a presentation at the American Urological Association 2014 annual meeting.
Factors associated with the presence of malignancy were an imaging tumor size of 2.5 cm or greater, male sex, and higher nephrometry score.
Mark Ball, MD, of Johns Hopkins University in Baltimore, and colleagues studied 1,097 patients who underwent partial nephrectomy for a single tumor smaller than 4 cm in diameter on imaging. The investigators defined unfavorable pathology as any grade III or IV renal cell carcinoma (RCC), any type II papillary RCC, pathologic T3 disease, or undifferentiated RCC.
A total of 825 patients (75.5%) were found to have RCC, and 219 (20% of the cohort) had unfavorable pathology. A tumor size of 2.5 cm or larger was associated with a significant 46% increased likelihood of RCC compared with a smaller tumor. RCC was nearly twice as likely to be found in men as women. A nephrometry score of 6 or higher was associated with a significant 54% increased likelihood of RCC compared with a lower score.
These factors may assist in risk stratification and selective renal mass biopsy prior to decision making, the authors concluded.
Prior studies have shown that 20%-30% of renal masses are found to be benign following partial nephrectomy, Dr. Ball’s group noted.