Analysis Of The Factors Associated With Bone Metastasis In Breast Cancer

Objective To analyze the clinicopathological factors affecting the occurrence of bone metastasis in breast cancer,and to explore the impactof these factors on the prognosis of breast cancer patients with bone metastasis.Methods 240 patients with breast cancer were collected from Liaoning Provincial People's Hospital during August 2011-August 2014.Correlation between bone metastasis and clinicopathological factors was tested by using X2 test and multivariable logistic regression.Cox regression models was used for survival analysis of patients with bone metastasis.The survival curve was described by Kaplan-Meier method and compared by Log-rank test.Results There were 240 cases of breast cancer,including 91 cases(37.9%)with bone metastasis.In 91 patients with bone metastases,the most common site of metastasis was the spine(74.7%),followed by the pelvis(48.3%),ribs(47.2%),sternum(42.9%),extremities(30.8%),skull(15.4%)and other(8.8%).Bone metastases were most common in multiple lesions.After univariate analysis,histological type,grade,ER status and molecular subtype were significantly correlated with bone metastases(p<0.05).Multivariate logistic regression analysis showded that ER status was an important factor affecting the occurrence of bone metastases in breast cancer patients(p=0.002).The median OS from the diagnosis of bone metastases was55 months.The median time of bone metastasis free survival(BMFS)was 34 months.Multivariable Cox model confirmed grade and molecular subtype were important factors affecting the survival of breast cancer patients with bone metastasis(p<0.05).Compared with luminal B breast cancer patients with bone metastasis,Luminal A patients have longer overall survival,and HER-2 and triple negative were the worst.The prognosis of high grade breast cancer patients with bone metastasis is worse than that of low grade breast cancer patients.Conclusion ER positivity is independent risk factor for breast cancer with bone metastases.Grade and molecular subtype are independent prognostic factors for overall survival in patients with bone metastases.