Oncological Outcomes of Different Patterns of Tumor Recurrence at First Evaluation After Bacillus Calmette-Guérin Induction Therapy for Intermediate and High Risk Non Muscle Invasive Bladder Cancer

Bladder cancer (BCa) is the second most common genitourinary malignancy with approximately 75-85% of all patients with BCa present at diagnosis a non-muscle invasive bladder cancer (NMIBC) (Ta, T1 and Tis). Although NMIBC usually carries a favorable prognosis, there is a high risk of disease recurrence and a 10% to 20% risk of progression to muscle-invasive disease.

The common treatment for intermediate- and high-risk patients is a transurethral resection followed by intravesical therapy with bacillus Calmette-Guerin (BCG), a non-specific immunotherapy that has remained the gold standard for 40 years. Over the last decades, several studies have confirmed the superiority of BCG over the combination of epirubicin and interferon, mitomycin C or epirubicin alone for prevention of tumor recurrence, in intermediate- and high-risk tumors.

Despite wide acceptance of BCG intravesical therapy in intermediate and high risk NMIBC, there is still a controversy regarding the optimal protocol of administration. However, most of the guidelines have recommended an induction regimen of six weekly BCG instillations followed by maintenance instillation for at least 1 year.

Complete response (CR) rates after an induction course of BCG for intermediate and high risk NMIBC are high and range from 50-70%. Tumor recurrence at first evaluation (3-months cystoscopy) after BCG induction therapy has been defined as a poor prognostic indicator in those groups of patients with an increased potential risk of disease recurrence and /or progression.

Different patterns of tumor recurrence may be encountered at 3-mo cystoscopy during first evaluation after induction therapy either morphological (single tumor vs. multiple, \<3 cm or more, site (? bladder neck involvement), papillary or non papillary) or histopathological (Ta vs. T1, concurrent CIS or not, tumor grade). To determine how to optimally manage those heterogeneous groups of patients, studying of the specific impact of different tumor characteristics on oncological outcomes is warranted.