Sarcopenia using pectoralis muscle area and lymphocyte-to-monocyte ratio (LMR) are independent prognostic factors in patients for nonmetastatic breast cancer

Sarcopenia is defined as loss of skeletal muscle mass and strength. This can lead to adverse clinical outcomes in patients with advanced cancer. The lymphocyte-to-monocyte ratio (LMR), a converted inflammatory response, is associated with poor prognosis in patients with malignancies. Herein, we examined the prognostic influence of sarcopenia status assessed by pectoralis muscle area (PMA), inflammatory status calculated by LMR, and its association with disease-free survival (DFS) in a cohort of women diagnosed with nonmetastatic breast cancer. A total of 293 patients with nonmetastatic breast cancer who underwent primary mass resection and radiotherapy between January 2011 and December 2017 were enrolled. The cross-sectional area of the muscle (cm(2)) at PMA was measured using computed tomography before radiation therapy. Baseline monocyte and lymphocyte counts were obtained from the complete blood count to calculate the LMR. Most of the patients (248/293, 84.6%) underwent breast conservation surgery. Lymph node involvement at diagnosis (hazard ratio [HR], 5.08; P < .001), low LMR (HR, 2.79; P = .007), and low PMA (HR, 3.80; P < .001) were independent poor prognostic factors in multivariate analysis. The mean DFS of sarcopenic and nonsarcopenic patients was 89.8 months and 118.8 months, respectively (P < .001). Sarcopenic patients with low LMR showed the worst outcomes, whereas nonsarcopenic patients with high LMR showed the best outcomes. Low PMA and low LMR were independent poor prognostic factors for DFS in patients with nonmetastatic breast cancer.