The Predictive Value Of Ki67 In Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

Backgrounds:Breast cancer is the malignant tumor from the epithelial tissue of breast, which has been one of the most common malignant tumor of global females since 1970s and the incidence rate of breast cancer is rising continuously. It has a higher incidence rate in women aged from 40 years old to 60 years old. Neo-adjuvant chemotherapy(NACT) is a kind of systematically chemotherapy, specific to operable and non-metastasis malignant tumor. NACT can reduce the size of primary tumor, clear tiny metastasis, decrease the metastasis rate of tumor cells and test the sensitivity of tumor cells chemical drugs in order to prepare for the post-operation chemotherapy and create conditions for partial treatments(surgery and radiotherapy). With the deeper clinical researches of NACT and stronger willings of breast conservation, NACT has become one of the most important treatments of breast cancer.Expressed in all phases of cell cycle except GO phase,the nuclei protein, Ki67 represent the proliferation rate of cells and can be measured by immunohistochemical methods.Many researches have been done to study the clinical meanings of Ki67,which show that Ki67 has correlations with the prognosis of breast cancer patients receiving neoadjuvant chemotherapy.Breast cancer is a heterogeneous disease and its immunohistochemical biomarkers and gene makers (the estrogen receptor (ER), progesterone receptor (PR), Her-2, and Ki-67) have relationships with the prognosis and efficacy of NACT,as well as tumor size,lymph node status and distant metastasis.[6]Miller-Payne Grading system, including five grades,analyze the chemotherapeutic effects on the reduction of tumor cells by comparing the post-operation pathological sections with the diagnostic fine needle biopsy before the neoadjuvant chemotherapy.Miller-Payne Grading system has marked manifestations on the neoadjuvant chemotherapeutic effects’analysis and sensitivity of tumor cells to chemical drugs guiding the post-operation treatment, and is meaningful to the evaluation of distant metastasis.Objective:By retrospective analysis of medical records of patients receiving neo-adjuvant chemotherapy and operation in Qilu Hospital of Shandong University, and combination of ER, PR, Her-2, age, nodule status and TNM stage, explore the correlations between the change of Ki67 before and after neo-adjuvant chemotherapy and effect of neo-adjuvant chemotherapy.Methods:Breast cancer patients received NACT in the Qi Lu Hospital of ShanDong Universtiy from Jan.2013 to Sept.2015 were collected. The criteria of collection:(1) Patients were female and diagnosed the primary unilateral invasive ductal carcinoma for the first time. The tumor is estimated and receiving none anti-tumor treatment. (2) The clinical stage of breast cancer is ⅢA ⅢB, ⅢC phase or clinical stage II A, II B period. (3) Patients are in good conditions and Karnofsky score≥80 points. Besides, heart, liver, lungs, kidneys and the other important viceras have normal functins. (4) All patients received clinical examination, abdominal B ultrasound, chest X-ray, bone scan aiming to exclude distant metastasis before NACT.(5) Patients were diagnosed invasive ductal carcinoma by pathology of fine needle core biopsy and immunohistochemistry were used for the test of sections before NACT and surgery sections.(6) 4-6 cycles of Docetaxel-based or Epirubicin-based (75mg/mm2) neoadjuvent chemotherapy were applied to the patients. (7)The relative integrity of patients’data was assured.80 integrated patients’data were collected.The immunohistochemical markers were measured in the hematoxylin and eosin stained sections after embedded by paraffin using monoclonal antibodies against Ki67,ER,PR and Her-2 conducted by the pathologists of the Pathology Department of Qi Lu Hospital.The ER and PR were regarded positive if> 1% nuclei were stained. According to the Recommendations For Human Epidermal Growth Factor Receptor 2 Testing In Breast Cancer published by the American Society of Clinical Oncology (ASCO) and the Association of American Pathologists (CAP) in February 2014, [8].No membrane staining in IHC staining was defined as negative(-); the positive cell count<10%, but no completely membrane staining was weak positive (1+); positive cell count from 10% to 30% with complete membrane staining was moderate positive (2+), and further test FISH was needed for IHC(2+); the positive cell count more than 30% was positive(3+). In this research, IHC(-) and IHC(1+) were defined as negative.Based on the measurement of parameters, patients were divided into four subtypes:luminal A (positive for ER and/or PR and negative for Her-2,Ki67<14%), luminal B (positive for ER and/or PR and positive for Her-2,Ki67at any level or negative for Her-2,Ki67≧14%),HER-2/neu overexpression (negative for ER and PR and positive for Her-2), and basal-like (negative for ER, PR, and Her-2).[9]Miller-Payne (MP) grading system was adopted for the NACT pathological evaluation of tissues and tumors cut off in the surgery.Miller-Payne Grading system includes five scale as follows:Grade l:no reduction in tumor cells;Grade2:<30% loss of overall cellularity. Not sensitivity to the chemical treatment.Grade3:30%-90% reduction of malignant cells.Grade4:≧90% loss of tumor cell burden. A significant diasppearance of tumor cells and only a small amount of or individual cells remains.Grade5:100% reduction in overall cellularity. No maliganant tumor cells can be found in the section of the tumor site.The pathological assessment was executed by two pathologists in Pathological Department of QiLu Hospital of Shandong University blindly. Based on the result of MP grading system, grade1-2 are pathological invalid and stable disease (stable disease, SD), grade3-4 are pathological partial remission(pathologic partial remission, pPR), and grade 5 is pathological complete remission (pathologic complete remission, pCR)., meaning no invasive tumor cells was found in the site of primary tumor and axillary lymph nodes resected in the surgery or only carcinoma in situ was found.The analysis used the statistics tool Statistic Package for Social Science(SPSS version 17.0) and Microsoft Office Excel 2007. One-Sample Kolmogorov-Smirnov Test was adopted to evaluate the normal distribution status of parameters and one-way ANOVA was applied while parameters were normally distributed and Wilcoxon rank sum test was used when parameters distributed abnormally.Results:1.The expression of Ki67 before NACT had no correlations with age (P=0.246), menstruation (P=0.243), nodule status (P=0.995) of breast cancer patients through K-S examination and one-way ANOWA analysis.2. There was connection between the value of Ki67 before NACT with breast cancer subtypes. Meanwhile, luminal A and luminal B (P<0.001), luminal A and Her-2 overexpression (P=0.001), luminal A and basal-like (P<0.001), luminal B and basal-like (P<0.001). Her-2 overexpression and basal-like had obvious difference with statistical meaning (P=0.005)3. The change of Ki67 before and after NACT in 80 breast cancer patients whose value of Ki67 decreased after NACT had no statistical correlations with the age (P=0.961), nodule status (P=0.668), TNM stage (P=0.795).4. The change of Ki67 before and after NACT had statistical connections with subypes of breast cancer, and the differences between luminal A and luminal B (P=0.033), luminal A and basal-like (P<0.001), luminal B and basal-like(P=0.019) had statistical meanings.5. The data distribution of three groups sorted by MP grading was normal, but no difference existed between three groups (P=0.659)Conclusion:1. The value of Ki67 in breast cancer patients has connections with the expression of ER, PR and Her-2 while not with patients’age, menstruation status or nodule status before NACT.2. NACT has inhibiting effects on the proliferation of tumor cells and the value of Ki67 has the obvious decline after NACT.3.There is no obvious statistical connections between the change of Ki67 before and after NACT and the age, lymph node status, TNM stage. And the value change of Ki67 has correlations with the expressions of ER, PR and Her-2.4.The change of Ki67 before and after NACT has no relevance with MP grading and the application of MP grading in the assessment of primary tumor chemotherapeutic reactions needs more consideration.5.ER, PR and Her-2 expressed by breast cancer cells can be regarded as predictive markers of NACT.