Neoadjuvant Chemotherapy in Non Muscle Invasive T1b Bladder Cancer

Bladder cancer (BC) is the most common malignancy of the urinary tract and the fourth most frequent cancer in the United States, with 79,030 new cases and 16,870 deaths estimated for 2017.

The most common presenting symptom is hematuria, which occurs in about 85% of patients. Hematuria is typically intermittent, gross, and painless. Bladder irritability, usually presenting as urinary frequency, urgency, and dysuria, occurs in about 20% of patients.

Initial diagnostic workup usually involves cystoscopy and urine cytology. Cystoscopy is the gold standard for the initial diagnosis and staging of bladder cancer. If a bladder mass is detected, a transurethral resection of the bladder tumor (TURBT) is performed for full primary tumor staging. The resected bladder tumor specimen should include muscle to fully assess the depth of tumor invasion. If carcinoma in situ (CIS) is detected, multiple random biopsies, including several different areas of the bladder and the prostatic urethra, may be required to assess the extent of involvement.

Abdominal imaging with either CT or MRI is recommended in patients with a high-grade tumor or muscle invasive disease to assess for local lymph node involvement, loco regional extent of disease and the presence of hydronephrosis.

Approximately 75% of patients with urothelial carcinoma of the bladder present with non-muscle-invasive bladder cancer (NMIBC), either confined to the mucosa (Ta and carcinoma in situ [CIS]) or invading the lamina propria (T1) . Clinical T1 high-grade (cT1HG) NMIBC has the highest rate of local recurrence and carries a significant risk of disease progression, clinical understaging, and death from urothelial carcinoma (UC) . The standard of care for adequately resected cT1HG NMIBC is intravesical Bacillus Calmette-Guerin (BCG) with early radical cystectomy (RC) for recurrent or refractory cT1HG disease Pathological upstaging to pathological tumor -2( pT2) is reported in approximately 50% when muscularis propria is absent from the original biopsy, and up to 25% will have lymph node (LN) metastases , which significantly increases the risk for cancer-specific death . These observations imply that a subset of patients with NMIBC that invades into the lamina propria is at a higher risk for clinical understaging and death from UC and may benefit from more aggressive therapy.

Long-term surveillance thus remains the cornerstone of long-term management, and cystoscopy has represented the gold standard modality for over 80 years.

Cisplatin- Gemcitabine (CG) neoadjuvant chemotherapy (NAC) provides pathological downstaging and improved overall survival (OS) for patients with muscle-invasive bladder cancer (MIBC) undergoing RC.

Chemotherapy administered in a neoadjuvant setting comes with some advantages: the ability to deliver effective systemic therapy while the burden of micrometastatic disease is low and is given in a setting in which the patient's performance status is optimal (patient more fit, no loss of renal function, eligibility to optimal cisplatin-based chemotherapy regimens).

High risk features (HRFs) in NMIBC were defined as follows: lymph-vascular invasion (LVI), thickening or induration on Examination under anesthesia( EUA) , tumor-associated hydronephrosis, and variant histology. Tumors with a primary urothelial component and presence of micropapillary, squamous, sarcomatoid, nested variant, glandular, plasmacytoid, adenocarcinoma, or lymphoepithelioma components were classified as tumors of variant histology ( ,also T1b substage has bad prognosis.

The investigators hypothesized that similar high-risk features (HRFs) might identify a high-risk subset of UC patients that could benefit from NAC in the absence of evidence for muscle invasion.