De-escalated therapy for HR+/HER2+ breast cancer patients with Ki67 response after 2-week letrozole: results of the PerELISA neoadjuvant study

BackgroundIn human epidermal growth factor receptor 2 (HER2+) breast cancers, neoadjuvant trials of chemotherapy plus anti-HER2 treatment consistently showed lower pathologic complete response (pCR) rates in hormone receptor (HR) positive versus negative tumors. The PerELISA study was aimed to evaluate the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HR+/HER2+ breast cancer patients selected on the basis of Ki67 inhibition after 2-week letrozole.Patients and methodsPerELISA is a phase II, multicentric study for postmenopausal patients with HR+/HER2+ operable breast cancer. Patients received 2-week letrozole, and then underwent re-biopsy for Ki67 evaluation. Patients classified as molecular responders (Ki67 relative reduction >20% from baseline) continued letrozole and started trastuzumab-pertuzumab for five cycles. Patients classified as molecular non-responders started weekly paclitaxel for 13 weeks combined with trastuzumab-pertuzumab. Primary aim was breast and axillary pCR. According to a two-stage Simon’s design, to reject the null hypothesis, at least 8/43 pCR had to be documented.ResultsSixty-four patients were enrolled, 44 were classified as molecular responders. All these patients completed the assigned treatment with letrozole-trastuzumab-pertuzumab and underwent surgery. A pCR was observed in 9/44 cases (20.5%, 95% confidence interval 11.1% to 34.5%). Among molecular non-responders, 16/17 completed treatment and underwent surgery, with pCR observed in 81.3% of the cases. PAM50 intrinsic subtype was significantly associated with Ki67 response and pCR. Among molecular responders, the pCR rate was significantly higher in HER2-enriched than in other subtypes (45.5% versus 13.8%, P = 0.042).ConclusionsThe primary end point of the study was met, by reaching the pre-specified pCRs. In patients selected using Ki67 reduction after short-term letrozole exposure, a meaningful pCR rate can be achieved without chemotherapy. PAM50 intrinsic subtyping further refines our ability to identify a subset of patients for whom chemotherapy might be spared.EUDRACT number2013-002662-40ClinicalTrials.gov IdentifierNCT02411344     

Immunocytochemical expression of Ki67 and laminin in Hurthle cell adenomas and carcinomas

BACKGROUND: Hurthle cell neoplasms may occur as a benign adenoma or carcinoma; the latter displays comparatively aggressive clinical behaviour. Fine-needle aspiration cytology (FNAC) represents a reliable tool for screening Hurthle cell lesions before surgery. Nevertheless, the cytological interpretation of these lesions is not always unequivocal. We analyzed cell growth and cellular adhesiveness by means of two different antibodies, Mib1 (Ki67) and laminin. AIM: The aim of the study was to analyze Ki67 and laminin immunocytochemical expression on FNAC to evaluate their usefulness in the preoperative differential diagnosis of Hurthle cell neoplasms. RESULTS: A higher expression of Ki67 has been recorded in malignant lesions as compared to benign ones (8% to 20% vs 1% to 5% nuclear staining, respectively; p < 0.001). An increased reactivity of anti-laminin antibody was recorded in the cytoplasm of cells from all malignant lesions. In Hurthle cell adenomas this adhesion molecule showed an intensity ranging from low to moderate. Moreover, a few benign lesions showing a moderate proliferative activity were associated with evident laminin expression. CONCLUSION: These findings support the hypothesis that benign Hurthle cell lesions with a high cellular proliferation associated with an increased laminin expression could define a subset of lesions prone to malignant transformation. Conversely, since all cases with low expression of both laminin and Ki67 always correspond to adenomas, we suggest that the different expression of these two antibodies on FNAC can provide a further tool for the preoperative identification of lesions at low risk of malignancy, thus avoiding unnecessary surgery.     

Interlaboratory variability of Ki67 staining in breast cancer

BackgroundPostanalytic issues of Ki67 assessment in breast cancers like counting method standardisation and interrater bias have been subject of various studies, but little is known about analytic variability of Ki67 staining between pathology labs. Our aim was to study interlaboratory variability of Ki67 staining in breast cancer using tissue microarrays (TMAs) and central assessment to minimise preanalytic and postanalytic influences.MethodsThirty European pathology labs stained serial slides of a TMA set of breast cancer tissues with Ki67 according to their routine in-house protocol. The Ki67-labelling index (Ki67-LI) of 70 matched samples was centrally assessed by one observer who counted all cancer cells per sample. We then tested for differences between the labs in Ki67-LI medians by analysing variance on ranks and in proportions of tumours classified as luminal A after dichotomising oestrogen receptor–positive cancers into cancers showing low (<14%, luminal A) and high (≥14%, luminal B HER2 negative) Ki67-LI using Cochran's Q.ResultsSubstantial differences between the 30 labs were indicated for median Ki67-LI (0.65%–33.0%, p < 0.0001) and proportion of cancers classified as luminal A (17%–57%, p < 0.0001). The differences remained significant when labs using the same antibody (MIB-1, SP6, or 30-9) were analysed separately or labs without prior participation in external quality assurance programs were excluded (p < 0.0001, respectively).ConclusionSubstantial variability in Ki67 staining of breast cancer tissue was found between 30 routine pathology labs. Clinical use of the Ki67-LI for therapeutic decisions should be considered only fully aware of lab-specific reference values.     

Comparison of immunohistochemistry and RT-qPCR for assessing ER,PR, HER2, and Ki67 and evaluating subtypes in patients with breast cancer

Breast Cancer Research and Treatment - Currently, the most commonly applied method for the determination of breast cancer subtypes is to test estrogen receptor (ER), progesterone receptor (PR),...     

Prognostic impact of discrepant Ki67 and mitotic index on hormone receptor-positive,HER2-negative breast carcinoma

Background:

Inconsistencies between mitotic index (MI) and Ki67 measures have been identified in many breast tumour samples. The aim of this study was to describe the prognosis of hormone receptor-positive (HR+) HER2− tumours having discrepant MI and Ki67.

Methods:

We included a cohort of breast cancer patients initially treated by surgery between 2001 and 2005 in the Institut Curie. Breast cancer-specific survival (BCSS) and disease-free survival (DFS) were analysed according to three proliferation groups: high MI/high Ki67 (MI=3, Ki67>20%), low MI/low Ki67 (MI<3, Ki67⩽20%) and discrepant (high MI/low Ki67 or low MI/high Ki67).

Results:

Among the 1430 patients, 19.6% had discrepant Ki67 and MI, 11.6% had high markers and 68.8% had low markers. The 5-year BCSS was 95.8%, 95% CI (0.93–0.98) in the discrepant group, 99.3%, 95% CI (0.993–0.999) in the low-proliferation group and 91.8%, 95% CI (0.88–0.96) in the high-proliferation group. In multivariate analysis, the survival of the discrepant group was lower than that of the low-proliferation group: BCSS hazard ratio (HR)=3.01 (1.32–6.84; P=0.008) and DFS HR=2.07, 95% CI (1.31–3.26; P=0.002). Among grade 2 tumours in multivariate analysis, DFS of the discrepant group was lower than that of the low MI/low Ki67 group: HR=1.98, 95% CI (1.14–3.46), P=0.02. Regarding BCSS, the obtained results were similar.

Conclusion:

The prognosis of patients with discrepant MI and Ki67 appears intermediate between that of low MI/low Ki67 and high MI/high Ki67 groups. These markers should be jointly analysed to clarify prognosis.     

Assessment of Ki67 in breast cancer: recommendations from the International Ki67 in Breast Cancer working group

Uncontrolled proliferation is a hallmark of cancer. In breast cancer, immunohistochemical assessment of the proportion of cells staining for the nuclear antigen Ki67 has become the most widely used method for comparing proliferation between tumor samples. Potential uses include prognosis, prediction of relative responsiveness or resistance to chemotherapy or endocrine therapy, estimation of residual risk in patients on standard therapy and as a dynamic biomarker of treatment efficacy in samples taken before, during, and after neoadjuvant therapy, particularly neoadjuvant endocrine therapy. Increasingly, Ki67 is measured in these scenarios for clinical research, including as a primary efficacy endpoint for clinical trials, and sometimes for clinical management. At present, the enormous variation in analytical practice markedly limits the value of Ki67 in each of these contexts. On March 12, 2010, an international panel of investigators with substantial expertise in the assessment of Ki67 and in the development of biomarker guidelines was convened in London by the co-chairs of the Breast International Group and North American Breast Cancer Group Biomarker Working Party to consider evidence for potential applications. Comprehensive recommendations on preanalytical and analytical assessment, and interpretation and scoring of Ki67 were formulated based on current evidence. These recommendations are geared toward achieving a harmonized methodology, create greater between-laboratory and between-study comparability, and allow earlier valid applications of this marker in clinical practice.     

Prognostic significance of geminin expression levels in Ki67-high subset of estrogen receptor-positive and HER2-negative breast cancers

Background

Indication for chemotherapy in estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancers is determined on the basis of Ki67 expression level. However, since Ki67-high cancers are not necessarily sensitive to chemotherapy, identification of such patients who do not need chemotherapy is an important issue.

Patients and methods

We used immunohistochemical staining to examine the expression levels of ER, progesterone receptor (PgR), Ki67, and geminin, a marker of S to G2/M phases, in 80 ER-positive/HER2-negative breast cancers. The labeling indices of Ki67 and geminin were determined and cutoff values were set at 15 and 6 %, respectively.

Results

Ki67 and geminin expression levels were significantly associated with nuclear grade. In the Ki67-low subset, 26 out of 28 (92.9 %) cancers were geminin low and in the Ki67-high subset, 31 out of 52 (59.6 %) were geminin high. Distant disease-free survival (DDFS) of the geminin-high subset was significantly poorer than that of the geminin-low subset (P = 0.009). In the Ki67-low subset, only one patient showed recurrence. Metastasis was detected in eight out of 31 (25.8 %) patients in the geminin-high group of the Ki67-high subset, but no recurrence was observed in the geminin-low group of the Ki67-high subset.

Conclusion

Geminin-high breast cancers are significantly associated with worse prognosis. Since poorer prognosis was recognized only in the geminin-high group in Ki67-high cancers, we speculate that geminin may be useful for identifying patients in the Ki67-high subset who can avoid unnecessary chemotherapy.

     

Ki67 immunostaining in primary breast cancer: pathological and clinical associations

Ki67 immunostaining has been performed on 136 primary breast cancers and related to various clinical and pathological features of the disease. Staining was most frequently seen in poorly differentiated tumours showing high rates of mitotic activity, but was independent of tumour size, lymph-node status and ER expression. A high level of Ki67 immunostaining was often associated with early recurrence of breast cancer after mastectomy. These data are consistent with the concept of the Ki67 antibody detecting an antigen that is closely related to cell proliferation and thus provides a clinically useful marker for this important characteristic of the tumour.     

胸苷激酶1和Ki67在乳腺癌中的表达及其对预后的价值

目的探讨胸苷激酶1（TKl）、Ki67单独表达及联合表达对乳腺癌复发转移的影响。方法选取广州医学院第二附属医院乳腺外科2005年3月至2007年6月问手术切除的乳腺癌患者组织标本65例,均经病理证实。分为A、B两组,A组37例,为乳腺癌在5年内出现复发或转移者,B组28例,为无瘤生存超过5年者。分别测量A、B两组TK1及Ki67表达情况并描述生存曲线。结果TKlA组阳性率为91．8％,B组阳性率67．8％（x2=6．116,P=0．013）,Ki67A组阳性率为78．4％,B组阳性率42．9％（X2=8．635,P=0．003）。A、B两组TKl和Ki67均呈阳性表达的比率分别为67．6％和39．3％（x2=5．159,P=0．023）。经Kaplan．Meier法生存曲线证实,与TK1和Ki67单独阳性表达者相比,联合阳性表达者的无瘤生存率显著降低,差异有统计学意义（x2=6．137,P=0．046）。结论TK1、Ki67均阳性表达是乳腺癌复发转移的高危因素,其预后较两者单独阳性表达者更差。     

Interobserver concordance of Ki67 labeling index in breast cancer: Japan Breast Cancer Research Group Ki67 Ring Study

The standardized assessment of Ki67 labeling index (LI) is of clinical importance to identify patients with primary breast cancer who could benefit from chemotherapy. In this study, we evaluated the interobserver concordance of Ki67 LI assessment. Six surgical pathologists participated and all the slides were prepared from archival breast cancer tissues fixed in 10% buffered formalin for 24 h and stained with MIB‐1. Three independent studies were conducted. In the first study, 30 stained slides were assessed using two different methods: the scoring system, with a positive rate scored from 1 (0–9%) to 10 (90–100%) by visual estimate; and the counting method, with approximately 1000 cells counted in hot spots. In the second study, 20 tumors with Ki67 LI 5–25% were assessed, and in the third study, 15 printed photographs of stained slides were assessed to avoid variations by selecting different fields. In study 1, the counting system (intraclass correlation coefficient [ICC], 0.66 [95% confidence interval 0.52–0.78]) demonstrated a better correlation than the scoring system (ICC, 0.57 [0.42–0.72]). In study 2, the assessment for Ki67 LI of 5–25% demonstrated a correlation (ICC, 0.68 [0.50–0.81]) similar to that of study 1 (unrestricted range of Ki67 LI). In study 3, the assessment of Ki67 LI by counting yielded a good concordance (ICC, 0.94 [0.88–0.97]). In conclusion, there was better concordance with the counting system, and concordance was high when the assessed field was predetermined, indicating that the selection of the evaluation area is critical for obtaining reproducible Ki67 LI in breast cancer.     

人表皮生长因子受体-2与细胞增殖抗原Ki67在乳腺癌组织中的表达及其临床意义

目的：探讨人表皮生长因子受体-2（HER-2）与细胞增殖抗原Ki67在乳腺癌组织中的表达情况及其与临床特征的关系。方法选取103例乳腺癌患者,获得组织标本,采用免疫组化方法检测HER-2与Ki67的表达水平,并分析其与临床特征之间的关系。结果103例乳腺癌患者中HER-2、Ki67染色阳性者分别有68例和78例,阳性率分别为66.02%和75.73%。TNM分期、淋巴结转移情况以及雌激素受体（ER）表达均影响HER-2表达（P﹤0.05）。Ki67阳性表达率在不同TNM分期和淋巴结转移情况的患者中比较,差异有统计学意义（P﹤0.05）。结论 HER-2和Ki67在乳腺癌组织中与患者的TNM分期和淋巴结转移情况相关,可作为重要的临床检测指标。     

Interobserver concordance in visual assessment of Ki67 immunohistochemistry in surgical excision specimens from patients with lymph node-negative breast cancer

Breast Cancer Research and Treatment - To explore the feasibility, adherence, safety and potential efficacy of Every Day Counts; a randomized pilot trial designed for women with metastatic breast...     

Ki67 targeted strategies for cancer therapy

Ki67 is a well-known proliferation marker for the evaluation of cell proliferation. Numerous studies have indicated that Ki67 index independently predicts cancer progression. Moreover, because Ki67 is highly expressed in malignant cells but almost could not be detected in normal cells, it has become a promising target for cancer therapy. In this review, we summarize recent advances in Ki67 targeted cancer therapy. In particular, we highlight recent development on the exploitation of Ki67 promoter to drive the expression of siRNAs or therapeutic genes in cancer cells specifically. The use of Ki67 as an attractive target opens a new avenue for cancer therapy.     

Prognostic significance of Ki67 index after neoadjuvant chemotherapy in breast cancer

Purpose

Recently, Ki67 index (cell proliferation marker) has been attracting a considerable attention as a prognostic factor in breast cancer but the prognostic significance of Ki67 after neoadjuvant chemotherapy (NAC) has rarely been examined.

Experimental design

Primary breast cancer patients (n = 102) treated with NAC (sequential paclitaxel 12 cycles (q1w) and 5-FU/epirubicin/cyclophosphamide 4 cycles (q3w)) were recruited in the study. Ki67, estrogen receptor (ER) and progesterone receptor (PR) and breast cancer resistant protein (BCRP) and P-glycoprotein were determined by immunohistochemistry and HER2 was determined by FISH in tumor tissues obtained before and after NAC, and their association with patient prognosis (relapse-free survival) was examined.

Results

Of the 102 patients, pCR was achieved in 30 (29.4%). In the 72 non-pCR patients, Ki67 index significantly (P < 0.001) decreased after NAC. Ki67 index after NAC, but not Ki67 index before NAC, was significantly associated with a patient prognosis (P = 0.022). Multivariate analysis has shown that Ki67 index after NAC is a marginally significant (P = 0.05) prognostic factor and that other biomarkers including ER, PR, BCRP, and P-glycoprotein before and after NAC are not significant.

Conclusions

Ki67 after NAC, but not before NAC, is prognostic in breast cancer patients, and might be clinically useful in the prognosis prediction of patients who do not achieve pCR after NAC. On the other hand, BCRP and P-glycoprotein before and after NAC are unlikely to be useful as prognostic factors in these patients.     

Ki67 measured in metastatic tissue and prognosis in patients with advanced breast cancer

The purpose of this study is to determine the prognostic role of Ki67 evaluated in relapse biopsies from patients with metastatic breast cancer (MBC). Two hundred and ten patients diagnosed with MBC in Stockholm, Sweden between 1998 and 2009 and with Ki67 assessed at time of first systemic relapse (mKi67) were retrospectively identified and divided into two groups according to mKi67 fraction (low ≤20 %, high >20 %). Post-relapse survival was compared between the groups using Kaplan–Meier and Cox regression methods. Death rate as function of continuous mKi67 was also evaluated. Furthermore, the prognostic role of intra-individual change in Ki67 between primary tumor and matched metastasis was explored by Kaplan–Meier plots. One hundred and twenty-five patients had low and 85 had high mKi67. Median survival was 25 and 17 months in low- and high-mKi67 group, respectively [hazard ratio (HR) 0.69, 95 % confidence intervals (CI) 0.51–0.92, P = 0.01]. In a multivariate model adjusted for prognostic confounders, low-mKi67 showed a non-significant trend toward better survival (HR 0.85, 95 %CI 0.62–1.16, P = 0.30). Nevertheless, mKi67 independently correlated with survival when compared with primary tumor proliferation (HR 0.56, 95 %CI 0.38–0.81, P = 0.002). The 2-year death rate steeply increased as mKi67 increased. Moreover, the change from high in primary tumor to low in metastasis significantly correlated with longer survival when compared with stable Ki67 levels (HR 0.48, 95 %CI 0.31–0.76, P = 0.002). In this cohort of MBC patients, mKi67 inversely but not independently correlated with survival. However, a significant association between mKi67 and survival was shown regardless of primary tumor proliferation.     

E-钙黏蛋白及Ki67在三阴性乳腺癌中的表达及临床意义

目的探讨E-钙黏蛋白、Ki67在三阴性乳腺癌(TNBC)中的表达及临床意义。 方法回顾性分析陆军军医大学新桥医院2010年1月至2013年12月收治的77例女性TNBC患者临床资料。采用免疫组织化学方法检测E-钙黏蛋白和Ki67的表达情况,通过χ²检验分析其与患者临床病理资料的关系。由于77例患者中有5例失访,本研究仅对随访资料完整的72例患者采用Kaplan-Meier法、Log-rank检验、Cox逐步回归模型进行生存分析和危险因素分析。 结果在77例患者中,E-钙黏蛋白的表达与淋巴结状态有关(χ²＝16.428,P<0.001),而Ki67表达与组织学分级有关(χ²＝7.218,P＝0.007)。中位随访59个月,72例患者的DFS率和OS率分别为58.3%、68.1%。其中,E-钙黏蛋白高表达者DFS率和OS率均高于低表达者(DFS率：75.9%比46.5%,χ²＝7.553,P＝0.006;OS率：82.8%比58.1%,χ²＝5.132,P＝0.023),而Ki67低表达者DFS率和OS率均高于高表达者(DFS率：84.0%比44.7%,χ²＝9.486,P＝0.002;OS率：92.0%比55.3%,χ²＝9.006,P＝0.003)。Cox逐步回归模型分析显示,淋巴结转移、组织学分级高是患者DFS的独立危险因素(OR＝4.030, 95%CI：1.854～8.757, P<0.001; OR＝2.879,95%CI：1.359～6.100,P＝0.006),Ki67高表达、淋巴结转移是OS的独立危险因素(OR＝5.067,95%CI：1.179～21.768, P＝0.029; OR＝6.253,95%CI：2.296～17.034, P<0.001)。 结论E-钙黏蛋白高表达和Ki67低表达的TNBC预后良好,这对于乳腺癌的个体化治疗具有一定的指导意义。