The Effect Of Molecular Typing On Breast Tumor Regression Model After Neoadjuvant Chemotherapy

ObjectiveThe objective of this study was to investigate the differences of shrinkage mode of the primary tumor in different molecular subtypes of breast cancer after neoadjuvant chemotherapy(NAC).Methods102 women with pathologically proven solitary invasive ductal carcinoma(IIA-IIIC)were recruited.All patients received whole cycles of NAC.Breast specimen was prepared with PMSS,and residual tumors were microscopically outline,scanned and registered by Photoshop software.The 3D model of residual tumors was reconstructed with 3D-Doctor software to evaluate the shrinkage model.RseultOf the 19 Luminal A types,concentric shrinkage mode(CSM)was 9(47.4%).non-concentric shrinkage mode(NCSM)was 10(52.6 %).Of 28 Luminal B(HER2-)types,concentric shrinkage mode was 15(53.6%).non-concentric shrinkage mode was 13(46.4%).Of the 19 Luminal B(HER2+)types,concentric shrinkage mode was 15(78.9%).non-concentric shrinkage mode was 4(21.1%).Of 10 HER2+ types,concentric shrinkage mode was 8(80%).non-concentric shrinkage mode was 2(20 %).Of 26 basal-like types,concentric shrinkage mode was 21(80.8 %).non-concentric shrinkage mode was 5(19.2%).There was a ststistically significant diference in the tumor shrinkage pattern brtween molecular subtypes(P<0.05).ConclusionLuminal B(HER2+)types,HER2+ types and basal-like types were more likely to have concentric shrinkage mode(78.9%,80% and 80.8% respectively).The Luminal A type and Luminal B(HER2-)type had no significant difference in primary tumor regression pattern(concentric shrinkage 47.4%,53.6%).Molecular typing is helpful to predict the regression mode of primary tumor after neoadjuvant chemotherapy in breast cancer,and help to further select the appropriate breast conserving therapy and reduce the local recurrence rate after neoadjuvant chemotherapy.