Analysis Of High Risk Factors Of Bone Metastasis In Patients With Postoperative Breast Cancer

Objective: To study relative risk factors of bone metastasis in patients withpostoperative breast cancer for reasonable interventions to increase the curative rate.Methods:We collected detailed information of160breast cancer patients who receivedradical mastectomy with postoperative pathology stage Ⅰ～Ⅲ，age29years to70years in the first affiliated Hospital of Dalian Medical University from January2007toDecember2010. With the median follow-up of62months from diagnosis to clearclinical factors associated with3-year recurrence rate and5-year recurrence rate usingchi-square test for univariate analysis. Putting the significant differences into the COXmodel regression method and identify the risk factors for the recurrence of postoperativebreast cancer. We selected80cases of archival paraffin-embedded tissue whounderwent postoperative adjuvant chemotherapy.We used immunohistochemicaltechnique Max VisionTM2/HRP method to detect the expression of PinX1in tumortissue. The relationship between the expression of PinX1and clinicopathologiccharacteristics(age,menstruation,number of node metastasis, tumor size, clinicalstage,ER/PR and HER-2expression) was investigated.Result:1.There were73cases of bone metastasis in160cases of breast cancerpatients, bone was the sole first metastatic site, and the disease remained confined tothe bone in34of them. The remaining patients (n=39) had both bone and visceralmetastasis at the time of first relapse.1-year ratio,3-year ratio,5-year ratio and morethan5-year ratio of bone metastasis were:15.1%(11/73)、43.8%(32/73)、30.1%(22/73)and11.0%(8/73). The median survival of postoperative bone metastasis was30 months.2.The factors(age,menstruation,number of axillary lymph node metastasis, clinicalstage, HER-2expression and molecular subtypes) were correlated with bonemetastasis postoperative in breast cancer,but the other factors there were no significantdifferences,such as tumor thrombus, tumor size, pathology category，ER/PR andhistology grade.3.The positive expression rate of PinX1was43.75%of80breast cancer patients. PinX1expression between the bone metastasis （40cases） and non-bone metastasis （40cases） were45%and42.5%,respectively（P>0.05）. The positive expression rate ofPinX1was no correlated with bone metastasis in all breast cancer patients.PinX1expression of non-axillary lymph node metastasis group was higher than axillary lymphmetastasis group (66.7%vs30%,P=0.006),and clinical stage Ⅰand Ⅱgroup was higherthan clinical stage Ⅲ(54.7%vs22.2%,P=0.021).PinX1expression was correlated withthe number of axillary lymph node metastasis and clinical stage（P<0.05）,but notcorrelated with other factors.4.Cox multivariate regression analysis shows that age at the time of operation（≤35year）, clinical stage（Ⅲ）and molecular subtypes (Luminal B) were the independentprognostic factors associated with bone metastasis in postoperative breast cancer.Conclusion:1.The study indicates that age at the time of operation（≤35year）, clinicalstage （Ⅲ），and molecular subtypes (Luminal B) are high risk factors associated withbone metastasis from breast cancer for patients after radical mastectomy.2. PinX1expression was correlated with the number of axillary lymph node metastasisand clinical stage, but no correlated with bone metastasis in all breast cancer patients.