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

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.

To describe preoperative changes in body composition in MIUC patients receiving platinum-based neoadjuvant chemotherapy (NC).

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.

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.

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.

Bladder cancer (Amsterdam, Netherlands). 2018 Oct 29*** epublish ***

Kalen J Rimar, Alexander P Glaser, Shilajit Kundu, Edward M Schaeffer, Joshua Meeks, Sarah P Psutka

Department of Urology, Feinberg School of Medicine of Northwestern University, Chicago, IL, USA., Department of Urology, University of Washington School of Medicine, Seattle, WA, USA.