Breast Cancer Shrikage Mode After Neoadjuvant Chemotherapy By Part Breast Sub-serial Sections

【Background】：Neoadjuvant chemotherapy (NAC) is one of the main strategies forpatients with locally advanced breast cancer. One dvantage associated with treatment withNC is that long-term survival of those who achieve pathological complete response (pCR)after NC can be significantly improved. Another potential advantage associated withtreatment with NC is that, it may increase the potential to offer breast-conserving therapy(BCT) if primary tumor has a significant response to chemotherapy. But what the mode oftumor shrinkage is and after NC,which patients can accept breast conserving are thesubjects worth exploring.【Objective】：The aims of our study is to observe chemotherapeutic response andshrinkage rules and analyze related factors by whole-mount serial section after breastcancer surgery, identify tumor pathological margin and reconstruct three-dimensionalpathological volume, observe three-dimensional morphology of breast cancer afterneoadjuvant chemotherapy, and find a intuitionistic and three-dimensional tumor mode forto guide BCT.【Methods】：A total of30patients with LABC were selected for this study afterconfirmation by palpation,Ultrasound,Magnetic resonance,Mammotome system biopsy and swollen lymph nodes diagnosis by fine needle aspiration cytology (FNAC).Tattoo dyemethod was used to mark the tumor border on the surface of the skin. All patients receivedfive or eight cycles NC and then subjected to a mastectomy. The residual tumors weremeasured by Magnetic resonance before NC,the middle of whole cycle and before surgery.Breast specimens were cut according to the original tumor border extending2cm. And thenthe specimens were cut consecutively to product Whole-mount serial section（sWMSS）intosets of4-7um at about3mm intervals. The PBSS were stained with hematoxylin andeosin, and were observed by pathology experts. The pathologist microscopically outlinedthe tumor containing area on each slides. Scanner was used to capture images of all theslides, then the two-dimensional images were processed with Adobe Photoshop9.0and thethree-dimensional model of residual tumors was reconstructed in computer with the3D-DOCTOR software.【Results】：(1)AccordingtoMagneticresonance, clinical response rat（ecRR）was90%,with12clinical complete responders (cCR)40%,15clinical partial responders (cPR)50%,and2no change (cNC)6.67%,one clinical progressive disease (cPD)3.33%, sevenpathological complete response（pCR）23.33%. There was statistical difference betweentumor size measured by Magnetic resonance before chemotherapy and pathological tumorrange after chemotherapy(9.62±28.18vs41.63±59.03,P=0.003), and tumor size measuredby Magnetic resonance before surgery and pathological tumor range afterchemotherapy(9.62±28.18vs9.21±29.83,P=0.523), and the accuracy of MRI is75.86%.The shrinkage modes of tumor after neoadjuvant chemotherapy is devided into two pattern:one is concentric and the number is46.67%(14/30);another is honeycomb and53.33%(16/30) belong this.During primary tumor of T≤3cm of T1~T3,10patients (62.5%)were concentric,4patients (36.36%)of T＞3cm of T1~T3were honeycomb;the number ofpCR were31.25%and18.18%respectively. All the patients of T4were honeycomb.Thenumber of pCR between finished all chemotherapy and finished50%chemotherapy were23.33%and3.33%respectively (P=0.023).Number of concentric between finished allchemotherapy and finished50%chemotherapy were46.67%and3.33%respectively(P=0.000). (2) Single factor variance analysis logistic regression analysis showed the shrink ofvolume of primary tumor was not related to tumor position,ER, HER2expression，ki67（P>0.05）. But tumor T stage are relate to the shrinkage of tumor（P=0.023）andER,HER2expression were relate to efficacy of chemotherpy of tumor（P=0.012vsP=0.025）.(3)The shrinkage patterns were divided into two types. One type wasconcentric,anothe was honeycomb. The shrinkage pattern of14patients’ tumor wasconcentric and the other’ was honeycomb.【Conclusions】：After all cycles neoadjuvant chemotherapy, tumor position,ER andHER2expression can not evaluate the shrink of volume of primary tumor.But tumor Tstage was relate to the shrinkage of tumor and ER, HER2expression were relate to efficacyof chemotherpy of tumor. The shrinkage modes of residual tumor after neoadjuvantchemotherapy is devided into two pattern: one type was concentric, anothe ishoneycomb.Tumor areas had decreased, and the tumor cells had lower densities withvarious degrees of degeneration.MRI showed the accuracy of MRI is75.86%.