Novel Grading System Predicts Poor Outcomes for Patients With pT1 NMIBC

A study from Maximilian Haas, MD, and colleagues sought to create a novel, prognostically relevant scoring system that includes tumor budding and growth and invasion patterns to evaluate patients with stage pT1 non-muscle invasive bladder cancer (NMIBC).

Researchers noted that the current World Health Organization grading system does not prioritize patients with stage pT1 NMIBC.

The study was published in BJU International.

Patients with stage pT1 NMIBC who received transurethral resection of bladder tumor were included in the trial. Investigators monitored tumor budding and growth and invasion patterns and organized them into 2 grade groups (GGs).

The GGs, as well as the clinical and histopathological variables, were analyzed for recurrence-free survival (RFS), progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS) through univariable and multivariable Cox regression analyses.

Dr. Haas and colleagues found that the incorporation of 2 tumor budding groups and growth and invasion patterns resulted in a subpar GG (n=28; 24.7%) that significantly influenced oncological outcomes.

They noted that the subpar GG was a predictor for RFS (P=.004) and OS (P=.046), as well as decreased PFS (P=.001) and CSS (P=.001), notwithstanding the European Association of Urology risk group. The subpar GG was also linked to increased rates of bacillus Calmette-Guerin-unresponsive tumors (P=.006)

Investigators reported that potential study limitations included the diverse therapies, small cohort, and retrospective, single-center design.

Dr. Haas and colleagues concluded that the novel grading system for stage pT1 NMIBC was associated with disease aggressiveness and oncological patient outcomes. They stated that patients with the disease variant who are identified as high risk by the scoring system should receive either intense follow-up or immediate radical cystectomy.

“The grading incorporates objective variables assessable on haematoxylin and eosin slides and immunohistochemistry, enabling an easy-to-use, low-cost approach that is applicable in daily routine,” the investigators observed. “Further studies are needed to validate and confirm these results.”