The Value Of MRI In Breast Conserving Surgery For Breast Cancer

ObjectiveAt present,the incidence of breast cancer is increasing year by year,seriously endangering the life and health of Chinese women.For the treatment of early breast cancer,breast conserving surgery(BCS)combined with postoperative radiotherapy,chemotherapy and / or endocrine therapy has become the main treatment method.The determination of tumor size,boundary,multi-center and multi-focal lesions and contralateral breast condition through imaging examination is the information that must be mastered before BCS.Due to the high sensitivity of breast MRI,it has been increasingly used in clinical practice.It can not only provide more evidence for thetreatment of breast cancer,but also it could change the initial treatment plan.This study retrospectively analyzed the difference of positive margin rate,reoperation rate and surgical change rate in BCS between the patients with breast MRI and without breast MRI before operative,and to investigate the effect of tumor/breast volume ratio on positive margin,so as to further explain the value of breast MRI in preoperative evaluation of breast conserving surgery.Materials and methodsA total of 109 cases of breast cancer patients who could be followed up for breast conserving surgery were collected during the period of 3 June 2015 to January 30,2018.Among them,52 patients who received breast MRI before surgery were the study group,and 57 patients who did not receive breast MRI before surgery were the control group.Complete clinical data were available in all cases.All patients were eligible for breast conserving surgery after routine examination and evaluation.The difference of positive rate of cut margin,reoperation rate and operation change rate between the two groups were compared.The tumor/breast volume ratio in the study group was measured.Tumor/breast volume ratios were measured on GE ADW 4.4workstation,using a semi-automatic operation,which measured the volume of tumor and breast respectively,and then calculated their ratio.It was worth noting that the incisal margin of 1cm was included in the measurement of tumor volume,because it was also the part to be excised in the surgical operation to ensure negative incisal margin.SPSS17.0 statistical software was used for statistical processing.Chi-square test was used to compare the counting data between groups.The rank sum test was used to compare the tumor/breast volume ratio between negative and positive surgical margins.The optimal bound was calculated from the subject operating characteristic(ROC)curve.P<0.05 was considered statistically significant.The difference of positive rate between the study group and the control group was measured by OR value and 95% confidence interval.ResultsThere was no significant difference in age,palpation positive results,malignant calcification by molybdenum target and pathological type between the study group and the control group(All P values were greater than 0.05).However,there was a statistically significant difference in the preoperative chemotherapy for tumor(P=0.013 < 0.05).The margin positive ratewas 15.4% and 15.8%(P>0.05)in study group and control group,respectively.Compared with the control group,the positive rate of incision margin of invasive carcinoma in the study group was lower,while that of ductal carcinoma in situ was higher.In the study group,two patients underwent improved radical resection and simple mastectomy in the following month,the control group had no reoperation.The rate of surgical change in two groups was9.6%(5 cases)and 12.3%(7 cases)(P>0.05).The volume ratio of tumors/breasts with negative margins in breast conserving surgery ranged from 1.08% to 28.03%,with a median of 4.17%;The volume ratio of tumors/breasts with positive margins in breast conserving surgery ranged from 4.06% to 27.68%,with a median of 13.47%.The tumor/breast volume ratio showed statistically significant difference between the negative and positive margin of resection in breast-conserving surgery(Z=-2.332,P=0.020<0.05).ConclusionMRI examination before breast conserving surgery does not reduce the positive margin rate,reoperation rate and surgical change rate of breast cancer patients,but the tumor-breast volume ratio is the influencing factor of the margin positive rate.