Neutrophil-Lymphocyte Ratio and Pathological Response to Neoadjuvant Chemotherapy in Patients with Muscle-Invasive Bladder Cancer

Background Cisplatin-based neoadjuvant chemotherapy (NC) improves overall survival in muscle-invasive bladder cancer (MIBC), but there are currently no predictive biomarkers of response to NC in MIBC. An increased peripheral blood neutrophil to lymphocyte ratio (NLR) is a marker of systemic inflammation and is linked to poor prognosis in some solid tumors. We evaluated whether NLR is associated with pathological response (pathR) in MIBC patients who receive NC. Patients and Methods MIBC patients treated with NC and radical cystectomy (RC) between July 2006 and April 2013 were retrospectively reviewed. The primary end point was to find variables associated with pathR in the RC specimen after NC. Potential predictive markers were analyzed using logistic regression. NLR values before NC, midway through NC, and before RC were collected and compared between patients who achieved pathR ('responders') and those who did not ('nonresponders'). Results In 26 evaluable patients, age, sex, performance status, smoking status, stage, hydronephrosis, NLR before NC, midway through NC, and before RC were not significantly associated with pathR, but the pattern of NLR change between responders and nonresponders was significantly different (P =.038). Responders exhibited a sustained decrease in NLR during NC until RC, and nonresponders exhibited a transient decrease in NLR which then increased to above its baseline before RC. Conclusion The pattern of change in NLR during NC varied significantly between responders and nonresponders. We hypothesize that a sustained decrease in inflammatory burden during NC is associated with pathR. Despite limitations of a small retrospective study, our observations might have clinical implications and warrant further basic and clinical research.