What is the ideal number of NACT cycles for muscle invasive bladder cancer?

Four cycles of neoadjuvant chemotherapy (NACT) results in better pathological response and survival than three NACT cycles in patients with muscle invasive bladder cancer, reveals a recent study.

A team of investigators conducted this cohort study to examine the pathological response rates and survival associated with three and four cycles of cisplatin-based NACT in patients with cT2-4N0M0 muscle invasive bladder cancer. Clinical data of 828 patients treated with NACT and radical cystectomy between 2000 and 2020 were analysed.

A total of 384 patients were treated with three NACT cycles and 444 with four cycles. The investigators assessed the pathological objective response (pOR; ypT0-Ta-Tis-T1 N0), pathological complete response (pCR; ypT0 N0), cancer-specific survival, and overall survival in the two cohorts.

Of the patients, 378 achieved pOR (45 percent, 95 percent confidence interval [CI], 42‒49) and 207 attained pCR (25 percent, 95 percent CI, 22‒28). Patients who received four NACT cycles had higher pOR (49 percent vs 42 percent; p=0.03) and pCR (28 percent vs 21 percent; p=0.02) rates than those treated with three cycles.

Multivariable logistic regression analysis confirmed this effect (pOR: odds ratio [OR], 1.46; p=0.008; pCR: OR, 1.57; p=0.007). On multivariable Cox regression analysis, four NACT cycles significantly correlated with overall survival (hazard ratio [HR], 0.68, 95 percent CI, 0.49‒0.94; p=0.02) but not with cancer-specific survival (HR, 0.72, 95 percent CI, 0.50‒1.04; p=0.08).

“These findings may aid clinicians in counseling patients and serve as a benchmark for prospective trials,” the investigators said. “Prospective validation of these findings and assessment of cumulative toxicity derived from an increased number of cycles are needed.”