Changes in Lean Muscle Mass Associated with Neoadjuvant Platinum-Based Chemotherapy in Patients with Muscle Invasive Bladder Cancer

Abstract

Background: Baseline sarcopenia or severe lean muscle deficiency is independently associated with increased mortality after cystectomy for muscle-invasive urothelial carcinoma of the bladder (MIUC). The impact of chemotherapy on muscle mass in MIUC patients remains undefined Objectives: To describe preoperative changes in body composition in MIUC patients receiving platinum-based neoadjuvant chemotherapy (NC). Methods: Patients with cT2-4 N0-1 M0 UC of the bladder who received NC were identified. Lumbar skeletal muscle index (SMI, cm2/m2), visceral adipose index (VAI, cm2/m2), and the subcutaneous and intramuscular adipose index (SAI, cm2/m2) were calculated using validated methodology (cross sectional area of skeletal muscle/height2 at L3) from measurement of soft tissue areas on pre-(pre-NC) and post-NC (post-NC) computed tomography. Patients were classified as sarcopenic according to consensus definitions: Male: SMI 55 cm2/m2, Female: SMI <38.5 cm2/m2. Pre-NC and post-NC median body mass index (BMI kg/m2), SMI, and adipose indices were compared. Results: The study cohort consisted of 26 patients, with a median age 70 years, including 7 females (27%). Chemotherapy regimens included dose-dense methotrexate, vinblastine, doxorubicin and cisplatin (31%), gemcitabine/cisplatin (62%) and gemcitabine/carboplatin (3.8%) with a median of 3.5 (range 2-6) cycles. Median pre-and post-NC BMI were 27.1 kg/m2 and 27.2 kg/m2 (p = 0.36). Median pre-and post-NC SMI were 49.1 cm2/m2 and 44.5 (p < 0.001) respectively. Median percent change in SMI was-6.4% (range-30% to 10%). Pre-NC, 18 (69%) patients were sarcopenic vs. 21 (81%, p = 0.002) post-NC. Median time between initiation of chemotherapy and cystectomy was 110 days. Conclusions: We observed a significant decrease in lean muscle mass among MIUC patients treated with platinum-based NC prior to cystectomy, with an associated increase in the prevalence of sarcopenia. Patients undergoing NC may benefit from pre-habilitative interventions to mitigate lean muscle loss prior to cystectomy.