Is Carcinoma In Situ Predictive of RFS in Patients With NMIBC?

A recent study analyzed the potential predictive benefits of pretreatment carcinoma in situ (CIS) and pretreatment positive urinary cytology for patients with non-muscle invasive bladder cancer (NMIBC).

Presented by Dr. Andrew B. Katims at the 24th Annual Meeting of the Society of Urologic Oncology, the study investigated if CIS and pretreatment positive urinary cytology could act as predictors for measurable residual disease (MRD).

Researchers noted that while prior research has indicated that CIS may be a surrogate for MRD, there is little supporting evidence for the theory.

Dr. Katims and colleagues prospectively recruited patients with bacillus Calmette-Guerin (BCG)-naive high-grade NMIBC (HGTa, HGT1, Tis). Patients were subsequently enrolled into a biospecimen protocol created to identify the predictors of response or resistance to BCG.

Patients underwent repeat transurethral resection of bladder tumor (TURBT) for 4 to 6 six weeks unless resection was not clinically indicated. Participating patients received a standard induction course of BCG +/- maintenance. For the first 2 years, researchers monitored patients every 3 months for recurrence using cystoscopy and urinary cytology. After 2 years, patients were monitored every 6 months or as otherwise determined.

Of the 177 participating patients, 174 (98%) underwent 6 instillations of BCG, and 76 (44%) received a minimum of 1 course of maintenance. A total of 56 (32%) patients experienced high-grade recurrence, while 17 (10%) underwent cystectomy. Following either the start or repeat treatment of TURBT, 68 patients (46%) had CIS.

Prior to receiving BCG but after treatment with TURBT, 121 patients received cytology results. Of those results, 63 (52%) were negative, 26 (21%) were atypical, 13 (11%) were suspicious, and 19 (16%) were positive.

Dr. Katims and colleagues concluded that there was no difference in high-grade recurrence-free survival (RFS) between patients with CIS and those without CIS (P=.85).

Researchers noted that patients with a negative urinary cytology showed an improved RFS rate, while patients with abnormal cytology experienced worse RFS.

“Our results suggest that CIS on pretreatment TURBT is a poor surrogate for MRD, and pretreatment urinary cytology is more predictive of disease recurrence,” the researchers wrote.