The Occurrence Analysis Of Skeletal-related Events And Establishment Of Novel Prognostic Scoring Model For Patients With Breast Cancer Spinal Metastasis

Breast cancer is one of the most common malignant tumors in women,which is easy to metastasize distally.Among the human system,skeletal system is the most common metastatic site of breast cancer,and the axial bone is more vulnerable than extremities.Spinal metastasis from breast cancer has always been the emphasis and difficulty of clinical diagnosis and treatment.On one hand,skeletl-related events(SREs)are likely to occur in patients with spinal metastasis,including radiotherapy for bone metastasis,orthopedic surgery,pathological fracture,spinal cord compression,and hypercalcemia,which could seriously affect the quality of life and deteriorate the prognosis.On the other hand,it is difficult to predict the life expectancy of patients with spinal metastasis,which may influence the optimal selection of treatment strategies and bring obstacles to the standard individualized therapy.Many studies on patients with breast cancer spinal metastasis have been performed.However,the research results are different and controversial.Currently,the risk factors of SREs,prognostic factors,and effective prognostic scoring model specific for breast cancer patient with spinal metastasis remain to be explored.Section ? ObjectiveTo explore the risk factors of SREs for breast cancer patients with spinal metastasis,and analyze the controversies of existing research results.MethodsRelevant clinical data and outcomes of 160 female breast cancer patients with spinal metastasis in Shanghai Jiao Tong University Medical School Affiliated Ruijin Hospital from January 2008 to August 2017 were retrospectively reviewed.All enrolled patients were divided into non-SREs group and SREs group according to the occurrence of SREs during disease course.The clinical features of patients were analyzed and compared between two groups.Univariate and multivariate analysis were performed using chi-square test and logistic regression analysis respectively.Clinical factors with P value <0.15 in univariate analysis were included into multivariate analysis,in order to explore the occurrence pattern and risk factors of SREs.ResultsIn this study,a total of 160 breast cancer spinal metastasis patients were enrolled with a mean age of 55.5±11.5 years(range,23-81 years).The number of patients with non-SREs and SREs was 75 cases(46.9%)and 85 cases(53.1%).According to univariate analysis,there were significant differences in visceral metastasis(P=0.013)and pathological classification of breast cancer(P=0.112)between two groups,while other clinical factors were not statistically significant.Multivariate analysis showed that both visceral metastasis(P=0.005)and pathological classification of breast cancer(P=0.041)could have an influence on the occurrence and progression of SREs.ConclusionsFor breast cancer patients with spinal metastasis,only bone metastasis and high pathological grade of breast cancer are independent risk factors of SREs.Section ? ObjectiveTo explore the independent prognostic factors for breast cancer patients with spinal metastasis,establish a novel scoring model for predicting the life expectancy,and evaluate its prognostic efficacy.MethodsThe 160 breast cancer spinal metastasis patients included in section one were retrospectively analyzed.All patients were randomly divided into training set and validation set in a ratio of 3:1.The potential factors,including age,general condition,pathological classification,molecular characteristics of breast cancer,bone metastasis site,number of bone metastasis,visceral metastasis,and serum tumor markers levels,were assessed in the training set.Univariate and multivariate analysis were performed using log-rank test and Cox proportional hazards analysis,and potential factors with P value <0.05 in univariate analysis were included into multivariate analysis.According to the significant factors and their regression coefficient,the novel prognostic scoring model was established,which was applied and evaluated in the validation set.ResultsThe median follow-up of 120 patients in training set and 40 patients in validation set were 32.0±21.6 months(range,1-118 months)and 31.5±30.3 months(range,1-115 months)respectively.The multivariate Cox regression analysis results showed that the general condition(P=0.012),hormone receptor status(P=0.017),visceral metastasis(P=0.001),and serum CA125 level(P=0.020)were independent prognostic factors for patients with breast cancer spinal metastasis.A survival prediction scoring algorithm comprising of these factors was created,which ranged from 0 to 7 points.According to the scoring model,three risk groups were identified that exhibited different prognoses: score 0-2 points was defined as low risk group,score 3-5 points was defined as intermediate risk group,and score 6-7 points was defined as high risk group.The Harrell C-index was 0.794 in the training set and 0.813 in the validation set,which reflected the high reliability and reproducibility of the novel model.ConclusionsFor breast cancer spinal metastasis patients,the general condition,hormone receptor status,visceral metastasis,and serum CA125 level can significantly affect the survival time.The prognostic scoring model comprising of these four factors can accurately predict the prognosis and help clinicians make individualized treatment program for patients.