Influence of body composition on survival in breast cancer patients with bone metastasis: a clinicopathologic-radiomic web-based nomogram development and validation

Abstract Background Bone metastasis (BM) reduces survival in breast cancer (BC) patients. Altered body composition is prognostic but poorly captured by conventional models; radiomics enables precise CT-based quantification. This study aimed to determine the influence of body composition on survival in BC patients with BM and to develop and validate a comprehensive web-based nomogram. Methods We retrospectively analyzed 197 breast cancer patients with bone metastasis at Tianjin Medical University Cancer Institute & Hospital, Tianjin, China, between January 2010 and December 2017. Another 38 patients from January 2012 to December 2016 in P.A. Hertsen Moscow Oncology Research Center, Moscow, Russia, as the external validation cohort to test the nomogram. The radiomics score for predicting survival was established by using the least absolute shrinkage and selection operator Cox regression. The Kaplan-Meier method was used for survival analysis. Multivariable Cox regression analysis was used to construct a clinicopathologic-radiomic web-based nomogram based on clinicopathologic and radiomics features of body composition. A clinicopathologic web-based nomogram was also established. Receiver operating characteristic curves and internal validation cohort were used to evaluate aforementioned nomograms. We verified the clinicopathologic-radiomic web-based nomogram model using the external validation cohort. Results The Kaplan-Meier analysis showed the 1-year survival in breast cancer patients with bone metastasis in construction cohort was 81.9%, the 3-year was 48.6%, the 5-year was 19.6%. Body composition was proved to be significantly correlated with the prognosis of breast cancer patients with bone metastasis. Eight variables were selected into the clinicopathologic-radiomic model: radscore, bone CT-value, bone metastasis location, pathology subtype, brain metastasis, ALP, Ca and TMI. The clinicopathologic-radiomic web-based nomogram was satisfactory with the C-index of 0.82, which was higher than the clinicopathologic model (C-index was 0.71). The AUCs of clinicopathologic-radiomic web-based nomogram in 1-, 3-, 5-years were internally validated (82.3%, 91.1% and 82.9%, respectively) and externally validated (85.1%, 84.3% and 67.7%, respectively). Conclusions Body composition was significantly associated with the prognosis of breast cancer patients with bone metastasis. Individualized rehabilitation training and nutritional support intervention should be encouraged for the patients. The established clinicopathologic-radiomic nomogram was an effective tool for prognostic prediction, and could help clinicians make personalized clinical decisions.