Prognostic Impact of Bone Mineral Density Reduction During Neoadjuvant Chemotherapy (NAC) in Patients Undergoing NAC Followed by Esophagectomy for Esophageal Cancer.

Background: Our previous study suggested that low bone mineral density (BMD), known as osteopenia, was a poor prognostic factor in patients who underwent esophagectomy for esophageal cancer (EC).Meanwhile, the association between BMD reduction during neoadjuvant chemotherapy (NAC) and the worse prognosis remains unknown, although esophagectomy after NAC is the first option for the treatment of advanced esophageal squamous cell carcinoma (ESCC). Therefore, this study intended to investigate the prognostic impact of BMD reduction during NAC.

Method: A total of 101 ESCC patients who underwent curative Mckeown esophagectomy after NAC between January 2008 and December 2019 were analyzed. BMD reduction (+) was defined as ≥ 6.8% of the BMD reduction rate during NAC. The patients were classified into the BMD reduction (+) group ( = 32) and the BMD reduction (-) group ( = 69) by measuring the BMD reduction during NAC.

Results: Overall survival (OS) and relapse-free survival (RFS) in the BMD reduction (+) group were significantly worse than those in the BMD reduction (-) group ( < 0.01). In multivariate analysis, BMD reduction was associated with worse OS (Hazard ratio [HR], 2.95; 95% confidence interval [CI], 1.44-6.05) and RFS (HR, 2.29; 95% CI, 1.30-4.03). Moreover, low skeletal muscle index before NAC was an independent risk factor for BMD massive reduction (Odds ratio, 6.21; 95% CI, 2.10-18.30).

Conclusions: BMD reduction during NAC was considered to be an adverse prognostic factor for OS and RFS in patients underwent NAC followed by esophagectomy for ESCC.