Ki67 Index in Breast Cancer: Correlation with Other Prognostic Markers and Potential in Pakistani Patients

Introduction: Breast cancer aggressiveness can be correlated with proliferation status of tumor cells, whichcan be ascertained with tumor grade and Ki67 indexing. However due to lack of reproducibility, the ASCO donot recommend routine use of Ki67 in determining prognosis in newly diagnosed breast cancers. We thereforeaimed to determine associations of the Ki67 index with other prognostic markers like tumor size, grade, lymphnode metastasis, ER, PR and HER2neu status. Methods: A total of 194 cases of newly diagnosed breast cancerwere included in the study. Immunohistochemical staining for ER, PR, HER2neu and Ki67 was performed bythe DAKO envision method. Associations of the Ki67 index with other prognostic factors were evaluated bothas continuous and categorical variables. Results: Mean age of the patients was 51.7 years (24-90). Mean Ki67index was 26.9% (1-90). ER, PR, HER2neu positivity was noted in 90/194 cases (46.4%), 74/194 cases (38.1%)and 110/194 cases (56.70%) respectively. Significant association was found between Ki67 and tumor grade,PR, HER2neu positivity and lymph node status, but no link was apparent with ER positivity and tumor size.There wasan inverse relation between Ki67 index and PR positivity, whereas a direct correlation was seen withHER2neu positivity. However, high Ki67 (>30%) was associated with decreased HER2neu positivity as comparedto intermediate Ki67 (16-30%). The same trend was established with lymph node metastasis. Conclusion: Ourstudy indicates that with high grade tumors, clinical utility of ki67 is greater in combination with other prognosticmarkers because we found that tumors with Ki67 higher than 30% have better prognostic profile comparedto tumors with intermediate Ki67 level, as reflected by slightly lower frequency of lymph node metastasis andHER2neu expression. Therefore we suggest that Ki67 index should be categorized into high, intermediate andlow groups when considering adjuvant chemotherapy and prognostic stratification.     

青年乳腺癌雌激素受体与Ki-67关系的研究

目的 研究青年乳腺癌雌激素受体表达与Ki-67指数的关系.方法 采用免疫组化S-P法,用抗ER、Ki-67单克隆抗体,研究32例青年乳腺癌和36例绝经后乳腺癌ER与Ki-67的表达.结果 青年乳腺癌17例(53.13%)ER阳性,绝经后乳腺癌20例(55.56%)ER阳性;青年乳腺癌ER阳性组Ki-67指数明显高于绝经后乳腺癌阳性组,差异有统计学意义(P＜0.01);而两者ER阴性组差异无统计学意义(P＞0.05).结论 青年乳腺癌ER阳性组肿瘤细胞增殖活性明显高于绝经后乳腺癌ER阳性组,这是青年乳腺癌恶性度高的重要原因.     

乳腺癌组织中ER、PR、cerbB-2、Ki-67表达及其意义

目的探讨乳腺癌组织中雌激素受体（ER）、孕激素受体（PR）、cerbB-2和Ki-67基因的表达及其临床意义。方法采用S-P免疫组化方法,检测107例乳腺癌组织中ER、PR、cerbB-2、Ki-67的表达水平,并结合其患者的相关临床资料进行分析。结果乳腺癌组织中ER、PR、cerbB-2、Ki-67阳性表达率分别为56.1%、82.2%、71.0%、67.3%。ER、PR、cerbB-2、Ki-67阳性表达与乳腺癌腋窝淋巴结转移和临床分期显著相关（P〈0.05）。而与患者年龄、肿瘤大小无相关性（P〉0.05）。相关分析结果显示ER与PR表达呈正相关（P=0.000）,与Ki-67表达呈负相关（P=0.000）;PR与cerbB-2、Ki-67表达呈负相关（P=0.012、0.006）。结论 ER、PR和cerbB-2、Ki-67与乳腺癌的发生、发展有关,联合检测ER、PR、cerbB-2和Ki-67,有助于客观评估乳腺癌的生物学行为,从而指导临床治疗和预后判断。     

HER2 Positive and HER2 Negative Classical Type Invasive Lobular Carcinomas: Comparison of Clinicopathologic Features

Human epidermal growth factor receptor 2 (HER2) positive (+) classical type invasive lobular carcinoma (cILC) of the breast is extremely rare and its clinicopathologic features have not been well characterized. We compared features of HER2(+) and HER2 negative (−) cILCs. A total of 29 cases were identified from the clinical database at our institution from 2011-2019; 9 were HER2(+) cILC tumors and 20 were HER2(−) cILC tumors. The results reveal that HER2(+) cILC group had significantly increased Ki-67 expression and reduced estrogen receptor (ER) expression compared to HER2(−) cILC group (both p < 0.05). In addition, HER2(+) cILCs tended to be diagnosed at a younger age and more common in the left breast, and appeared to have a higher frequency of nodal or distant metastases. These clinicopathologic features suggest HER2(+) cILC tumors may have more aggressive behavior than their HER2(−) counterpart although both groups of tumors showed similar morphologic features. Future directions of the study: (1) To conduct a multi-institutional study with a larger case series of HER2(+) cILC to further characterize its clinicopathologic features; (2) to compare molecular profiles by next generation sequencing (NGS) assay between HER2(+) cILC and HER2(−) cILC cases to better understand tumor biology of this rare subset of HER2(+) breast cancer; and (3) to compare molecular characteristics of HER2(+) cILC and HER2(+) high grade breast cancer in conjunction with status of tumor response to anti-HER2 therapy to provide insight to management of this special type of low grade breast cancer to avoid unnecessary treatment and related toxicity     

激素受体和HER-2及Ki-67预NSL腺癌新辅助化疗疗效价值的分析

目的：探讨乳腺癌组织中雌激素受体（ER）、孕激素受体（PR）、人表皮生长因子受体2（HER-2）及Ki-67的表达状态对新辅助化疗反应的预测作用以及化疗前后其表达差异对疗效的影响。方法：免疫组织化学方法检测新辅助化疗前后118例乳腺癌组织的ER、PR、HER-2及Ki-67的表达情况,并分析其与新辅助化疗疗效的关系。结果：118例新辅助化疗乳腺癌病例中,ER-和PR-组pCR分别为26．1％和27．1％,明显高于ER＋组11．1％和PR＋组6．8％,P-0．003。HER-2和Ki-67的表达对新辅助化疗疗效无显著影响。新辅助化疗前ER、PR与Ki-67的表达呈明显负相关,P〈0．001;新辅助化疗后Ki-67的高表达病例数显著减少,P-0．001。结论：ER-／PR-的患者对新辅助化疗更为敏感,Ki-67在化疗后发生了显著下调,提示新辅助化疗能降低肿瘤的增殖活性。ER、PR及Ki-67可以作为新辅助化疗疗效的预测指标。     

The Case to Case Comparison of Hormone Receptors and HER2 Status between Primary Breast Cancer and Synchronous Axillary Lymph Node Metastasis

Background: Nowadays, the adjuvant treatment for breast cancer patients chosen depends on immunohistochemical pattern of Estrogen receptor(ER), Progesterone receptor(PR) and HER2 status of primary breast tumor. Several retrospective studies showed significant discordance in receptor expression between primary and metastatic tumors. The objective of this research was to determine discordant rate of ER, PR and HER2 status between primary breast cancer and synchronous axillary lymph node metastasis of individual breast cancer patients in Thammasat University Hospital. Methods: A prospective observational study of all breast cancer patients who have axillary metastasis and underwent surgery at Thammasat Hospital between January 2011 to December 2015. Tumor staging, ER, PR, and HER2 status on primary breast tumor were recorded. Synchronous axillary lymph node metastasis was evaluated with immunohistochemistry for ER, PR, and HER2. Results: The ER-positive rate from primary tumor to synchronous axillary lymph node metastasis decreased from 74.7% to 71.7%; the HER2 overexpression rate was decreased from 26% to 24%. In contrast, PR positive rate were 71% in both primary tumor and synchronous axillary lymph node metastasis. In case to case comparison, discordance rate of ER, PR and HER2 status between primary breast cancer and synchronous axillary lymph node metastasis were 11.1%, 20.2% and 10.1%, respectively. Furthermore, the tumor staging was not significant associated with discordance of ER, PR and HER2. Conclusion: ER, PR and HER 2 biomarkers showed significant concordance between primary tumor and synchronous axillary lymph node metastasis. Hence, if we cannot assess the ER, PR and HER2 status in primary tumor, then synchronous axillary lymph node metastasis can be studied instead. However, the repeat of biomarker testing in node-positive breast cancer patients may be beneficial for tailored adjuvant therapy, especially for patients with negative hormone receptor and/or HER2 profile on primary tumor.     

ER、PR与C-erbB-2、Ki-67在乳腺癌中的表达及其临床意义

目的 探讨乳腺癌组织中ER、PR与C-erbB-2、Ki-67的表达及它们的相关性.方法 采用免疫组化检测,对356例乳腺癌患者ER、PR、C-erbB-2及Ki-67的表达、临床病理特征以及它们的相关性进行回顾性分析.结果 ER、PR、C-erbB-2及Ki-67的表达与淋巴结转移相关(P<0.05);乳腺癌组织分级...     

Immunohistochemical Analysis of ER,PR, Her2 and CK5/6 in Infiltrative Breast Carcinomas in Indian Patients

Aim: Breast cancer is biologically a heterogeneous disease. Patients with the same diagnostic profile havemarkedly different clinical outcomes. Gene expression studies identified distinct breast cancer subtypes thatdiffer in prognosis. Aim is to identify the immunohistochemical subtypes of breast carcinoma and correlate theresults with pathological features associated with adverse prognosis in our study population. Method: We included107 consecutive cases of invasive breast carcinoma and sub classified using immunohistochemical staining forER, PR, Her2, and CK5/6 into the following subtypes: luminal A, luminal B, basal-like, Her2+ and unclassified.Associations between tumor subtypes and tumor characteristics were examined. Results: The proportion ofeach subtype in our patient population was: luminal A 37.4%, luminal B 11.1%, Her2+ 29% and basal-like7.5%. The following variables were significantly associated with IHC breast cancer subtypes: patient age (p<.05),overall histopathology grade (p<0.001), nuclear grade (p<0.005) and mitotic index (p<0.001). Her2+ and basallike subtypes were associated with poor differentiation (p<0.01), higher nuclear grade (p<0.05) and high mitoticindex (p<0.05). Conclusions: Our data show a higher proportion of patients in the study population undergototal mastectomy and harbor poorly differentiated, node positive tumors than reported. There was also a relativelyhigh percentage of the Her2+ subtype (29%).     

Association between GSTP1 Genotypes and Hormone Receptor Phenotype in Invasive Ductal Carcinomas of Breast

Eighty six cases of invasive ductal breast carcinomas were utilized to investigate GSTP1 polymorphisms incertain immunohistochemistry (IHC) subtypes of breast cancer with respect to ER, PR and HER2 expression.The frequency of wild allele homozygote, heterozygote and variant allele homozygote genotypes were 46.5%,52.3% and 1.16% respectively; Whereas 54.3% of the control subjects were GSTP1 wild type allele homozygous,40.0% were heterozygous and 5.71% mutant allele homozygous. There was dramatic inverted relation betweenpositive IHC ER staining and increasing grade of tumors in general (100%, 88.6%, 40.4%) and especially amongtumors with heterozygote genotype of GSTP1 (70%, 35.4%, 22.7). There was increase in positive IHC HER2staining consistent with higher grades in general (20%, 29.6%, 50.0%), especially among tumors with GSTP1wild allele homozygote genotype (5.0%, 9.1%, 31.8%). A remarkable reverse relation was also observed betweenthe fraction of IHC hormone receptor phenotype ER+/PR+/ HER2- and increased grade of tumors (60.0%,45.5%, and 27.3%) especially among tumors with GSTP1 heterozygote genotype, and a similar link was notedregarding ER+/PR-/ HER2- and tumor grade. There was increase in frequency of ER-/PR-/ HER2- (0.0%, 6.8%,and 18.2%) and ER-/PR-/ HER2+ (0.0%, 4.54%, and 40.9%) consistent with the higher grades of tumors ingeneral and especially GSTP1 heterozygote genotype tumors. As a conclusion, there is no correlation betweenGSTP1 polymorphism and increased risk of breast cancer i.e. the mutant allele is randomly distributed in cancerand control cases. However, there is a link between GSTP1 genotypes and hormone receptor expression statusand certain phenotypes of breast cancer, which may have clinical importance.     

Ki-67表达与多西他赛联合顺铂治疗三阴性乳腺癌疗效的关系

目的：探讨三阴性乳腺癌（ TNBC）组织Ki-67表达与多西他赛联合顺铂化疗疗效之间的关系。方法选取术后胸壁局部复发和（或）区域淋巴结转移的女性TNBC患者50例,复发或转移病灶行穿刺活检术,应用免疫组化方法检测Ki-67的表达,分为区域淋巴结转移组、无区域淋巴结转移组,Ki-67阳性表达组及阴性表达组。应用多西他赛联合顺铂方案化疗,3周期后进行疗效评价。结果区域淋巴结转移组及无区域淋巴结转移组Ki-67阳性表达差异有统计学意义（χ2=4.402,P=0.036）。3周期化疗后Ki-67阳性表达组有效率85.71%（30/35）,Ki-67阴性表达组有效率60.00%（9/15）,差异有统计学意义（χ2=4.406,P=0.044）。结论多西他赛联合顺铂治疗术后出现胸壁局部复发和（或）区域淋巴结转移的TNBC疗效较好, Ki-67阳性表达的TNBC患者对该方案化疗更敏感。     

survivin在乳腺癌中的表达及其与Ki-67和c-erbB-2表达的关系

目的：观察凋亡抑制蛋白survivin在乳腺癌组织中的表达,及其与c-erbB-2、Ki-67增殖指数的相关性及临床病理意义。方法：应用免疫组织化学SP法检测survivin在正常乳腺组织（20例）和乳腺癌组织（96例）中的表达以及Ki-67、c-erbB-2在乳腺癌组织中的表达。结果：survivin阳性表达乳腺癌的Ki-67增殖指数(35.32±21.28)%明显高于survivin阴性者(20.42±11.34)%,survivin表达与肿瘤细胞增殖呈正相关(P<0.01);survivin在乳腺癌组织中的阳性表达率为70.83%(68/96),正常乳腺组织未见survivin表达;survivin蛋白的表达与c-erbB-2的表达呈正相关（P<0.01）;survivin蛋白的表达与临床分期、淋巴结转移和5年生存率有关(P<0.05),与年龄、是否绝经、肿瘤大小和组织学分级均无关。结论：survivin不仅参与凋亡的调控,还促进了细胞增殖,在乳腺癌发生、发展中起重要作用,过度表达提示预后不良。     

Thymidine labeling index and Ki-67 growth fraction in breast cancer: Comparison and correlation with prognosis

Summary In situ determination of proliferative activity was performed on 184 consecutive primary invasive breast cancers. Methods used were monoclonal antibody Ki-67 in immunohistochemistry and thymidine labeling index. Tumor proliferation correlated between both methods (p = 0.0001). For thymidine labeling index and Ki-67, respectively, significant correlations existed with histologic tumour grade and steroid hormone receptors (Tumor grade: TLIp = 0.0001; Ki-67 p = 0.0001. ER-ICA: TLI = 0.0001; Ki-67 p = 0.014. PgR-ICA: TLIp = 0.0001; Ki-67 p = 0.0008).For thymidine labeling index a significant correlation was demonstrated for overall survival (p = 0.001) and recurrence free survival (p = 0.01). No statistical significance was observed for clinical outcome and Ki-67 (overall survival p = 0.18; recurrence free survival p = 0.1). None of the factors, TLI or Ki-67, was an independent prognostic factor as demonstrated by multivariate analysis.     

乳腺癌新辅助化疗后不同时间Ki-67变化规律研究

目的:观察乳腺癌新辅助化疗后不同时间肿瘤细胞Ki-67表达水平的变化情况,研究乳腺癌新辅助化疗后肿瘤细胞增殖变化的规律,探讨依此指导选择化疗最佳间期的可行性.方法:将乳腺癌组织接种于裸鼠前腿根部皮下,待其成活并生长到0.3～0.4 cm时,随机分为8组,取其中1组肿瘤组织应用免疫组化法测定肿瘤细胞Ki-67表达水平,其余7组行CAF(环磷腺胺、多柔比星和5-氟尿嘧啶)方案化疗1次,分别在化疗后1、3、5、7、14、21和28 d取肿瘤组织,应用免疫组化法测定肿瘤细胞Ki-67表达水平.结果:乳腺肿瘤细胞Ki-67表达水平从化疗后第3天开始逐渐降低,至化疗后14 d时降到最低点,然后又逐渐升高,至化疗后28 d时已接近化疗后第5天水平.结论:乳腺癌新辅助化疗后肿瘤细胞的增殖有其特定的变化规律,应用免疫组化法测定化疗后肿瘤细胞Ki-67表达水平,有可能指导临床选择最佳化疗间期,从而提高乳腺癌新辅助化疗效果.     

Differential Expression of RAGE,EGFR and Ki-67 in Primary Tumors and Lymph Node Deposits of Breast Carcinoma

Background: Breast cancer is a complex disease that results from the inheritance of a number of susceptible genes.Intensive search wok was conducted world-wide on molecular bases of breast cancer in order to achieve the besttherapeutic modalities; however, breast cancer still remains a challengeable task. It is very important to determine ifthe biological parameters in metastatic regional lymph nodes are similar to that in the primary breast cancer becausetherapy is indicated for patients with synchronous metastatic regional lymph nodes of breast cancer. Difference intherapeutic response in cases of breast cancer may be assumed partially to variability in the biological behavior of tumortissue in primary breast cancer and lymph node metastasis. Aim: Our aim is to evaluate any variability in the expression ofthree types of tissue markers in both the primary breast tumors and corresponding axillary lymph nodes in order toexpect the targeted therapeutic effect on both sites. Material and Methods: Three markers from different categories;RAGE, EGFR and Ki-67 were immunohistochemicalyl studied for their expression in biopsy specimens from primarybreast tumors and their corresponding axillary lymph nodes. Results: There was a statistically significant difference inthe expression of these markers between benign and malignant breast lesions.Although we found some differences inthe expression of the three studied markers between primary breast cancer and corresponding axillary lymph nodes, yetthese variations were mostly not statistically significant. Conclusion: Our findings support the validity of anti-RAGEand anti-EGFR therapy for treatment of both primary and nodal metastatic breast cancer in immunopositive cases.     

Ki-67表达水平检测在乳腺癌新辅助化疗疗效评估中的价值

目的:回顾性分析88例乳腺癌新辅助化疗前、后Ki-67在肿瘤组织的表达情况,探讨Ki-67表达与新辅助化疗疗效的关系,评价其在乳腺癌新辅助化疗中的预测作用.方法:选取2015年9月至2016年9月河北医科大学第四医院乳腺中心收治的88例Ⅱ-Ⅲ期乳腺癌患者,检测新辅助化疗前空芯针穿刺肿瘤组织及术后标本中Ki-67的表达,分析其与新辅助化疗疗效及临床相关病理因素的关系.结果:新辅助化疗的临床总有效率为59.09%(52/88),Ki-67高表达组对化疗敏感,化疗效果明显优于Ki-67低表达组(P<0.05);新辅助化疗可明显降低Ki-67的高表达率(P<0.01);新辅助化疗后Ki-67表达下降组化疗有效率显著高于其他组(P<0.05).结论:Ki-67在乳腺肿瘤组织中的表达可作为新辅助化疗疗效临床评价指标之一,预测新辅助化疗的疗效,为个体化治疗提供依据.     

乳腺癌新辅助化疗前后Ki-67、HER-2、ER和PR的变化与临床缓解率的关系

目的 比较新辅助化疗前后的乳腺癌患者肿瘤组织中Ki-67、HER-2、ER和PR的改变,探索其变化与临床缓解情况之间的关系。方法 回顾性收集接受新辅助化疗的乳腺癌患者103例,本次观察前均未行任何放疗、化疗和内分泌治疗。化疗前接受14 G空心针刺活检诊断为局部浸润性导管癌或小叶癌。患者经4个周期化疗后94例患者接受手术切除。化疗前后的肿瘤组织采用福尔马林固定,石蜡包埋病理切片法,免疫组化染色法检测化疗前后肿瘤组织中Ki-67、HER-2、ER和PR的变化情况。采用WHO标准评价化疗后的临床缓解率。结果 103例病例经新辅助化疗后有9例发生转移,94例经化疗后进行了手术治疗。术前穿刺和术后肿瘤组织切片染色比较,Ki-67、ER和PR表达发生了明显的改变,而HER-2的前后变化差异不显著。但是,仅Ki-67的表达变化与肿瘤缓解率的关系显著。结论 在乳腺癌的新辅助治疗中,Ki-67的变化可能作为预测新辅助化疗肿瘤缓解率的一个指标,对临床用药和化疗结局有一定的指示作用。     

青年乳腺癌Ki-67的表达及其与临床病理的关系

目的探讨青年乳腺癌患者Ki-67的表达情况以及与临床特点和病理学特征的关系。方法收集67例临床病理资料完整的青年乳腺癌病例（年龄在35岁以下）,免疫组化方法检测癌组织中Ki-67的表达情况,并与病理组织学分级、患者TNM分期、腋淋巴结转移数目进行比较分析,选取同期35岁以上中老年妇女乳腺癌患者410例进行对照。结果青年组乳腺癌Ki-67阳性表达率分别为73．13％,中老年组分别为58．78％,青年组Ki-67阳性率明显高于后者（P〈0．05）;Ki-67与病理组织学分级、TNM分期、腋淋巴结转移数目呈正相关（γ〉0,P〈0．05）。结论青年乳腺癌侵袭性强、预后差,可能与癌组织中Ki-67的高表达有关;检测乳腺癌组织中Ki-67的表达情况对判断乳腺癌预后及指导治疗有一定的拳者意义。     

核呼吸因子-1和Ki-67在乳腺癌组织中的表达及意义

探讨核呼吸因子-1（NRF-1）蛋白表达与乳腺癌发生发展、临床病理特征及Ki-67的关系。方法:采用免疫组化EnVision二步法,对211例乳腺癌组织、50例乳腺良性病变组织中NRF-1和Ki-67进行检测。结果:NRF-1表达定位于细胞核,在乳腺癌中表达率为87.2%,低于乳腺良性病变组织的100%（χ2=100.288,P<0.001）;高分化乳腺癌NRF-1表达率明显高于中、低分化乳腺癌（χ2=16.242,P=0.001;χ2=72.802,P<0.001）,中分化乳腺癌也明显高于低分化乳腺癌（χ2=30.190,P=0.000）。乳腺癌淋巴结转移患者NRF-1表达率明显低于未转移者（χ2=12.025,P=0.007）;TNM分期中I期NRF-1表达率明显高于Ⅱ、Ⅲ期（χ2=12.025,P=0.007）。211例乳腺癌中Ki-67表达率为78.7%,Ki-67表达与NRF-1（χ2=42.914,P<0.001）、病理组织学分级（χ2=40.239,P<0.001）、淋巴结转移（χ2=16.061,P=0.001）和TNM分期（χ2=13.589,P=0.004）间比较差异有统计学意义。结论:NRF-1参与了乳腺癌的发生发展,也与Ki-67表达有相关性,可作为乳腺癌患者疾病进展监控和预后观测的指标,有可能成为乳腺癌新的治疗靶点。      

Higher Ki67 Expression is Associates With Unfavorable Prognostic Factors and Shorter Survival in Breast Cancer

Background: The prognostic value of the Ki67 expression level is yet unclear in breast cancer. The aim of thisstudy was to investigate the association between Ki67 expression levels and prognostic factors such as grade, Her2and hormone receptor expression status in breast cancers. Materials and Methods: Clinical and pathologicalfeatures of the patients with breast cancer were retreived from the hospital records. Results: In this study, 163patients with breast cancer were analyzed, with a mean age of 53.4±12.2 years. Median Ki67 positivity was 20%and Ki67-high tumors were significantly associated with high grade (p<0.001), lymphovascular invasion (p=0.001),estrogen receptor (ER) negativity (p=0.035), Her2 positivity (p=0.001), advanced stage (p<0.001) and lymphnode positivity (p<0.003) . Lower Ki67 levels were significantly associated with longer median relapse-free andoverall survival compared to those of higher Ki67 levels. Conclusions: High Ki67 expression is associated withER negativity, Her2 positivity, higher grade and axillary lymph node involvement in breast cancers. The levelof Ki67 expression is a prognostic factor predicting relapse-free and overall survival in breast cancer patients.     

Expression of ER, Ki-67 and CylinD1 in the Pre-cancerous Breast of Chinese Patients

To investigate the expression and association of ER, Ki-67 and cyclinD1 in usual ductal hyperplasia(UDH), atypical ductal hyperplasia (ADH) and ductal carcinoma in situ(DCIS) in the breast. The study included 56 cases of pre-cancerous lesions which were surgically excised at Qi Lu Hospital of Shangdong University. Immunohistochemistry was used to determine the expression of ER, Ki-67 and cyclinD1 and double-labelling immunofluorescence technique was used to observe the coexpression of ER and Ki-67. The expression and distribution of ER-positive cells were significantly different in UDH, ADH and DCIS. The ER-positive cells were much more in UDH than in normal TDLUs (terminal duct lobular units). The distribution of ER-positive cells interspersed amid ER-negative cells within UDH. However , the ER positive cells showed marked increases in ADH and low grade nuclear DCIS (P < 0.05), distributing in almost all constituent cells. The expression of ki-67 and cyclinD1 were significantly different between UDH and DCIS (P < 0.05) , and a positive correlation was found between expression of Ki-67 and morphological classification of pre-cancerous lesions (r = 0.3522, P < 0.05) as well as cyclinD1 (r = 0.3901, P < 0.05). Double-labelling immunofluorescence showed that there was no coexpression of ER and Ki-67 in normal breast tissue. The coexpression of the two markers was found in ADH and increased in DCIS. Overexpression of ER, Ki-67 and cyclinD1 significantly accompanies the transition of normal cells and UDH to ADH and DCIS. The coexpression of ER and ki-67 may present the early change in carcinogenesis of breast cancer.