Stage pT3a kidney cancer is a catch-all title, says urologist Nirmish Singla, M.D., Director of the Kidney Cancer Program, and not all cancers in this group are equal. “By definition, stage pT3a kidney cancers are locally advanced and invasive,” he explains. “However, some pT3a tumors invade the perinephric fat (fat around the kidney), some reach into the fat in the renal sinus (a space within the kidney), and some invade the renal vein or its branches. There can also be any combination of these features.” Because the pT3a category is so broad, “simply defining a pT3a tumor by its pathologic stage may not adequately reflect its aggressiveness.”

In a recent analysis of the SEER registry, a comprehensive database of case statistics maintained by the National Cancer Institute, former Brady urologic oncology fellow Michael Rezaee, M.D., M.P.H., and colleagues examined the different pT3a subtypes of more than 10,000 patients diagnosed with renal cell carcinoma (RCC). They found that patients who had a combination of two or more invasive subtypes were more likely to die of their cancer than those with just one subtype. “This discrepancy in survival was most pronounced in patients with stage pT3a papillary RCC,” says Singla, senior author of the study, which was published in Urologic Oncology: Seminars and Original Investigations. “Invasion of the renal vein or its branches portended the worst prognosis, followed by renal sinus fat invasion, followed by perinephric fat invasion.”

This study has important ramifications for delivering patient-specific treatment, Singla continues. “In patients with locally advanced RCC who are treated with surgery, there is a growing interest in perioperative (neoadjuvant and/or adjuvant) therapeutic strategies to reduce the risk of recurrence and death.” At the same time, the goal is to not overtreat patients. “Our work highlights the need to refine pT3a staging criteria to help guide individualized, multimodal strategies to treat locally advanced kidney cancers.”