Topoisomerase IIalpha expression rather than gene amplification predicts responsiveness of adjuvant anthracycline-based chemotherapy in women with primary breast cancer

Elucidating the prognostic and therapeutic significance of TOP2A in various malignancies

Topoisomerase IIα (TOP2A) is a crucial enzyme that plays a vital role in DNA replication and transcription mechanisms. Dysregulated expression of TOP2A has been associated with various malignancies, including hepatocellular carcinoma, prostate cancer, colon cancer, lung cancer and breast cancer. In this review, we summarized the prognostic relevances of TOP2A in various types of cancer. The increased expression of TOP2A has been linked to resistance to therapy and reduced survival rates. Therefore, evaluating TOP2A levels could assist in identifying patients who may derive advantages from molecular targeted therapy. The amplification of TOP2A has been linked to a positive response to chemotherapy regimens that contain anthracycline. Nevertheless, the overexpression of TOP2A also indicates a heightened likelihood of disease recurrence and unfavorable prognosis. The prognostic significance of TOP2A has been extensively studied in various types of cancer. The increased expression of TOP2A is associated with poor clinical outcomes, indicating its potential as a valuable biomarker for assessing risk and stratifying treatment in these malignancies. However, further investigation is needed to elucidate the underlying mechanisms by which TOP2A influences cancer progression and to explore its potential as a therapeutic target.

GINS1 promotes the proliferation and migration of glioma cells through USP15-mediated deubiquitination of TOP2A

GINS1 is a GINS complex subunit that functions along with the MCM2-7 complex and Cdc45 in eukaryotic DNA replication. Despite the significance of the GINS complex in the switch between quiescence and proliferation of glioma cells inside and outside the perinecrotic niche, the biological functions and the underlying mechanism of GINS1 remain unclear. Unlike in normal cells and tissues, GINS1 expression level was significantly upregulated in glioma cells and tissues. High expression of GINS1 predicted an advanced clinical grade and a poor survival. Functional assays revealed that GINS1 aggravated glioma malignant phenotypes in vitro and in vivo. Mechanistically, this study identified that GINS1 physically interacts with TOP2A. GINS1 promotes glioma cell proliferation and migration through USP15-mediated deubiquitination of TOP2A protein. Our results delineate the clinical significance of GINS1 in glioma and the regulatory mechanisms involved in glioma cell proliferation and migration. This work provides potential therapeutic targets for glioma treatment.

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GINS1 expression was upregulated and associated with poor clinical outcome in glioma

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GINS1 aggravated glioma malignant phenotypes in vitro and in vivo

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GINS1 physically interacts with TOP2A

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GINS1 regulates glioma progression through USP15-mediated deubiquitination of TOP2A

A careful reassessment of anthracycline use in curable breast cancer

It has been over three decades since anthracyclines took their place as the standard chemotherapy backbone for breast cancer in the curative setting. Though the efficacy of anthracycline chemotherapy is not debatable, potentially life-threatening and long-term risks accompany this class of agents, leading some to question their widespread use, especially when newer agents with improved therapeutic indices have become available. Critically assessing when to incorporate an anthracycline is made more relevant in an era where molecular classification is enabling not only the development of biologically targeted therapeutics but also is improving the ability to better select those who would benefit from cytotoxic agents. This comprehensive analysis will present the problem of overtreatment in early-stage breast cancer, review evidence supporting the use of anthracyclines in the pre-taxane era, analyze comparative trials evaluating taxanes with or without anthracyclines in biologically unselected and selected patient populations, and explore published work aimed at defining anthracycline-sensitive tumor types.

Prognostic and predictive value of the combination of TOP2A and HER2 in node-negative tumors 2 cm or smaller (T1N0) breast cancer

BACKGROUND

We aim to evaluate the prognostic and predictive value of TOP2A and HER2 expression in T1N0 breast cancer patients.

METHODS

299 cases with T1N0 breast cancer were obtained from the Oncomine database (Cohort 1) and 963 of T1N0 breast cancer patients from Sun Yat-sen Memorial Hospital (Cohort 2) were retrospectively enrolled. Kaplan-Meier product was applied to estimate survival curve. Cox proportional hazard models was used to identify prognostic factors. We used PSM (propensity score matching) to balance clinicopathologic characteristics among four groups of different HER2/TOP2A status. Survival between groups and chemotherapy regimens were analyzed, before and after PSM.

RESULTS

In Cohort 1, we found that the group with HER2+ and higher expression of TOP2A mRNA was associated with poor breast cancer-specific survival (BCSS) compared to the group of HER2- with lower expression of TOP2A mRNA. In Cohort 2, HER2+ patients with higher TOP2A protein expression had greater risk of recurrence and distant recurrence compared to HER2- patients with lower expression of TOP2A protein. Among the patients who developed both HER2+ and higher expression of TOP2A protein and received chemotherapy, patients who received an anthracycline-based regimen had a significantly better recurrence-free survival (RFS) than those with a non-anthracycline-based regime.

CONCLUSION

Patients with both HER2+ and high expression level of TOP2A protein predicts poor prognosis in T1N0 breast cancer patients. Patients with double positive for TOP2A protein and HER2 may benefit from anthracycline-based regimens.

The prognostic significance of topoisomerase II alpha protein in early stage luminal breast cancer

BACKGROUND

Topoisomerase II alpha (TOP2A) protein has been shown to be a proliferation marker associated with tumor grade and Ki67 index. The prognostic effect of TOP2A seems different among different subtypes of breast cancer. The current study evaluated the prognostic impact of TOP2A protein on luminal breast cancer.

METHOD

Altogether 434 stage I-II luminal breast cancer patients who underwent curative surgery in Sun Yat-Sen University Cancer Center between 2007 and 2009 were enrolled. TOP2A protein expression was assessed by immunohistochemistry. Clinical and pathological data were retrospectively collected.

RESULT

With a cut-off value of 30%, 127 (29.3%) patients were classified as TOP2A overexpression. TOP2A overexpression was associated with a higher tumor grade and Ki67 index. Patients with TOP2A high expression showed a significantly higher rate of distant metastasis and shorter distant metastasis free survival (DMFS) compared with patients with low TOP2A expression. The prognostic influence of TOP2A expression was more significant in years 5-8 after diagnosis, and more pronounced in stage II patients, luminal B disease, and patients treated with adjuvant endocrine therapy alone. Multivariate survival analysis revealed TOP2A overexpression was an independent fact for worse DMFS.

CONCLUSION

TOP2A protein showed a time dependent influence on prognosis in stage I-II luminal breast cancer, suggesting it might be a potential predictor of late recurrence for this group of patients.

High expression of topoisomerase-II predicts favorable clinical outcomes in patients with relapsed small cell lung cancers receiving amrubicin

OBJECTIVES

Amrubicin monotherapy is a treatment option for patients with relapsed small cell lung cancers (SCLCs). Topoisomerase-II (Topo-II) - a target of amrubicin - has been reported as a predictive or prognostic marker for chemosensitivity or outcomes in patients with various malignancies. Here, we investigated the prognostic role of Topo-II expression in patients with relapsed SCLCs who underwent amrubicin monotherapy.

MATERIALS AND METHODS

Eighty-three patients with relapsed SCLCs who received amrubicin monotherapy between 2004 and 2015, after progression beyond first-line chemotherapy, were enrolled in the study. We retrospectively collected clinical data from their medical records, and evaluated the expression levels of Topo-II, by immunohistochemical staining of archival tumor specimens obtained through surgical resections or biopsies.

RESULTS

Most of the enrolled patients were elderly men (89%), with a median age of 70 years (range, 49-83); 16% of these patients showed Topo-II overexpression. Compared to patients with sensitive relapses, those with refractory relapses showed significantly higher Topo-II expression levels (P=0.03). The overall response rates in patients with high and low Topo-II expression were 38.5% and 25.7%, respectively (P=0.34). Multivariate analysis confirmed that patients with a higher Topo-II expression level had significantly longer progression-free survival (hazard ratio (HR), 0.39; P<0.01) and overall survival (HR, 0.48; P=0.04), compared to patients with a lower Topo-II expression level.

CONCLUSION

Our study identified Topo-II expression as a significant biomarker for the prediction of favorable outcomes in patients with relapsed SCLCs who underwent treatment with amrubicin, a Topo-II inhibitor. Thus, Topo-II expression may be a promising predictor of the efficacy of amrubicin.

TOP2A amplification and overexpression in hepatocellular carcinoma tissues

Hepatocellular carcinoma (HCC) is the leading cause of cancer death in men worldwide owing to limited insights into pathogenesis and unsatisfactory efficacy of current therapies. HER2 and TOP2A genes are coamplified in breast and some other cancers. In this study, we investigated gene aberrations of HER2 and TOP2A and protein expressions of HER2, TOP2A, Ki-67, and p53 in tumor and matched nontumor tissues, as well as their associations with clinicopathological features. Gene aberrations were evaluated by FISH and protein expressions by IHC. Neither HER2 overexpression nor HER2 gene amplification was observed in both tumor tissues and matched nontumor tissues. By contrast, TOP2A overexpression was detected in 72.5% of tumor tissues but not detected in matched nontumor tissues. However, TOP2A gene amplification was not observed in both tumor and matched nontumor tissues. TOP2A overexpression was significantly associated with HCC tumor tissues (P < 0.001), hepatitis B surface antigen (HBsAg) in the serum (P = 0.004), and Ki-67 (P = 0.038) but not with age, tumor size, alpha-fetoprotein, TP53, and copy number of TOP2A gene and chromosome 17 centromere. In conclusion, TOP2A overexpression in HCC was not secondary to gene amplification. In addition, neither HER2 amplification nor overexpression could be used as prognostic and predictive marker in HCC.

Correlation between ER, PR, HER-2, Bcl-2, p53, proliferative and apoptotic indexes with HER-2 gene amplification and TOP2A gene amplification and deletion in four molecular subtypes of breast cancer

The aim of our study was to investigate HER-2 and TOP2A gene status and their correlation with Bcl-2, p53, Ki67, ssDNA, and clinicopathological parameters in four molecular subtypes of breast cancer. Seventy-four paraffin-embedded samples are immunohistochemically studied for the expression of estrogen receptor (ER), progesterone receptor (PR), HER-2, p53, Bcl-2, ssDNA, and Ki67, while HER-2 and TOP2A gene status by fluorescence in situ hybridization was investigated in 60 samples. Luminal A and B subtypes were characterized with small tumor size, intermediate histological grade, negative lymph node, and metastatic status, while triple negative and HER-2 positive subtypes were associated with larger tumor size, poorly differentiated tumors, and positive lymph node status. p53, Ki67, and ssDNA expression was higher in triple negative and HER-2 positive than in luminal subtypes, while ER, PR, and Bcl-2 dominated in luminal subtypes. HER-2 gene status was higher in luminal B and HER-2 positive than in luminal A and triple negative subtypes, while TOP2A gene status was similar. HER-2 gene status positively correlated with TOP2A gene status, HER-2 receptor, and histological grade, while negative correlation characterized relationship between HER-2 gene status and ER, PR, and Bcl-2. The shortened overall survival period characterized patients from triple negative breast cancer subtype (18.7 months). HER-2 and TOP2A gene amplification showed a tendency to be associated with larger tumor size, positive lymph node status, high level of apoptotic and proliferative indexes, and low level of p53 and Bcl-2 expression, which all together indicate group of patients with similar outcome during the progression of the disease.

TOP2A overexpression as a poor prognostic factor in patients with nasopharyngeal carcinoma

Despite the advances in diagnostic imaging and treatment modalities, the risk stratification and final outcomes in patients with nasopharyngeal carcinomas (NPC) still remain suboptimal. Through data mining from published transcriptomic database, topoisomerase IIα (TOP2A) was first identified as a differentially upregulated gene in NPC tissues, which implicates cell division via selective cleavage, rearrangement, and re-ligation of DNA strands. Given the roles of TOP2A in prognostication and in the frontline therapeutic regimen of common carcinomas, such as breast cancer, we explored TOP2A immunoexpression status and its associations with clinicopathological variables and survival in a well-defined cohort of NPC patients. TOP2A immunohistochemistry was retrospectively performed and analyzed using H-score method for biopsy specimens from 124 NPC patients who received standard treatment without distant metastasis at initial diagnosis. Those cases with H-score larger than the median value were construed as featuring TOP2A overexpression. The findings were correlated with the clinicopathological variables, disease-specific survival (DSS) and distant metastasis-free survival (DMFS). TOP2A overexpression was significantly associated with American Joint of Cancer Committee (AJCC) stages III-IV (p = 0.019) and univariately predictive of adverse outcomes for DSS (p = 0.0078) and DMFS (p = 0.0003). In the multivariate comparison, TOP2A overexpression remained prognostically independent to portend worse DSS (p = 0.047, hazard ratio = 1.732) and DMFS (p = 0.003, hazard ratio = 2.569), together with advanced AJCC stages III-IV. TOP2A expression is upregulated in a subset of NPCs and its increased immunoexpression significantly correlated with advanced stages and tumor aggressiveness, justifying the potentiality of TOP2A as a prognostic biomarker and a novel therapeutic target of NPC.

Evaluation of the prognostic role of centromere 17 gain and HER2/topoisomerase II alpha gene status and protein expression in patients with breast cancer treated with anthracycline-containing adjuvant chemotherapy: pooled analysis of two Hellenic Cooperative Oncology Group (HeCOG) phase III trials

BACKGROUND

The HER2 gene has been established as a valid biological marker for the treatment of breast cancer patients with trastuzumab and probably other agents, such as paclitaxel and anthracyclines. The TOP2A gene has been associated with response to anthracyclines. Limited information exists on the relationship of HER2/TOP2A gene status in the presence of centromere 17 (CEP17) gain with outcome of patients treated with anthracycline-containing adjuvant chemotherapy.

METHODS

Formalin-fixed paraffin-embedded tumor tissue samples from 1031 patients with high-risk operable breast cancer, enrolled in two consecutive phase III trials, were assessed in a central laboratory by fluorescence in situ hybridization for HER2/TOP2A gene amplification and CEP17 gain (CEP17 probe). Amplification of HER2 and TOP2A were defined as a gene/CEP17 ratio of >2.2 and ≥2.0, respectively, or gene copy number higher than 6. Additionally, HER2, TopoIIa, ER/PgR and Ki67 protein expression was assessed by immunohistochemistry (IHC) and patients were classified according to their IHC phenotype. Treatment consisted of epirubicin-based adjuvant chemotherapy followed by hormonal therapy and radiation, as indicated.

RESULTS

HER2 amplification was found in 23.7% of the patients and TOP2A amplification in 10.1%. In total, 41.8% of HER2-amplified tumors demonstrated TOP2A co-amplification. The median (range) of HER2, TOP2A and CEP17 gain was 2.55 (0.70-45.15), 2.20 (0.70-26.15) and 2.00 (0.70-26.55), respectively. Forty percent of the tumors had CEP17 gain (51% of those with HER2 amplification). Adjusting for treatment groups in the Cox model, HER2 amplification, TOP2A amplification, CEP17 gain and HER2/TOP2A co-amplification were not associated with time to relapse or time to death.

CONCLUSION

HER2 amplification, TOP2A amplification, CEP17 gain and HER2/TOP2A co-amplification were not associated with outcome in high-risk breast cancer patients treated with anthracycline-based adjuvant chemotherapy.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12611000506998 and ACTRN12609001036202.

Iron chelators with topoisomerase-inhibitory activity and their anticancer applications

SIGNIFICANCE

Iron and topoisomerases are abundant and essential cellular components. Iron is required for several key processes such as DNA synthesis, mitochondrial electron transport, synthesis of heme, and as a co-factor for many redox enzymes. Topoisomerases serve as critical enzymes that resolve topological problems during DNA synthesis, transcription, and repair. Neoplastic cells have higher uptake and utilization of iron, as well as elevated levels of topoisomerase family members. Separately, the chelation of iron and the cytotoxic inhibition of topoisomerase have yielded potent anticancer agents.

RECENT ADVANCES

The chemotherapeutic drugs doxorubicin and dexrazoxane both chelate iron and target topoisomerase 2 alpha (top2α). Newer chelators such as di-2-pyridylketone-4,4,-dimethyl-3-thiosemicarbazone and thiosemicarbazone -24 have recently been identified as top2α inhibitors. The growing list of agents that appear to chelate iron and inhibit topoisomerases prompts the question of whether and how these two distinct mechanisms might interplay for a cytotoxic chemotherapeutic outcome.

CRITICAL ISSUES

While iron chelation and topoisomerase inhibition each represent mechanistically advantageous anticancer therapeutic strategies, dual targeting agents present an attractive multi-modal opportunity for enhanced anticancer tumor killing and overcoming drug resistance. The commonalities and caveats of dual inhibition are presented in this review.

FUTURE DIRECTIONS

Gaps in knowledge, relevant biomarkers, and strategies for future in vivo studies with dual inhibitors are discussed.

Prognostication of prostate cancer based on TOP2A protein and gene assessment: TOP2A in prostate cancer

Background

TOP2A encodes for topoisomerase IIα, a nuclear enzyme that controls DNA topological structure and cell cycle progression. This enzyme is a marker of cell proliferation in normal and neoplastic tissues; however, little information is available about its expression in prostate cancer (PCa).

Methods

Immunohistochemistry (IHC) was automated using mouse monoclonal antibody against TOP2A (clone SWT3D1; DAKO, Carpenteria, CA, USA) at dilution 1:800 and Flex Plus detection system in autostainer 48Ultra (DAKO). FISH was performed using TOP2A (17q21)/ CEP17 probe kit (Kreateck Biotechnology, San Diego, CA, USA). Biochemical and pathological data from 193 patients with PCa were retrieved for the analysis, whose significance was considered when p < 0.05. Also, fractal analysis was performed in a subset of 20 randomly selected cases.

Results

TOP2A protein expression correlated with higher Gleason scores and higher levels of preoperative PSA (p = 0.018 and p = 0.011). Patients with higher levels of TOP2A presented shorter biochemical recurrence-free survival (BRFS) (p = 0.001). In multivariate analysis, we found that TOP2A remained an independent prognostic factor of BRFS, with a relative risk of 1.98 (p = 0.001; 95% CI, 1.338–2.93); thus, cases that expressed high levels of this enzyme had a shorter BRFS compared with TOP2A-negative or TOP2A-low cases. No alterations in TOP2A gene status nor correlation between FISH and IHC results were observed. Concerning fractal analysis, patients who expressed higher levels of TOP2A have angiolymphatic invasion and presented higher Gleason scores (p = 0.033 and p = 0.025, respectively). Also, patients with higher expression of TOP2A presented shorter BRFS (p = 0.001).

Conclusions

This is the first study to perform TOP2A protein and gene digital assessment and fractal analysis in association with BRFS in a large series of PCa. Also, we show that TOP2A gene copy number alterations are not observed in this type of tumor. So, higher protein expression of TOP2A is not related to gene amplification in PCa. Furthermore, TOP2A protein assessment has prognostic importance and, due to its relation with poor outcome, TOP2A IHC evaluation in the biopsy can represent an important tool for selecting the most suitable surgical and clinical approach for patients with PCa.

Her-2/neu and topoisomerase IIα in advanced breast cancer: a comprehensive FISH analysis of 245 cases

Her-2/neu gene amplification is an established prognostic factor in breast cancer, and Her-2/neu protein is the target of the therapeutic monoclonal antibody Herceptin. More recently, topoisomerase IIα became a new focus of breast cancer research because of its role as a target for anthracycline therapy. Therefore, we compared Her-2/neu and topoisomerase IIα amplification/deletion in a large series of advanced breast cancer using fluorescence in situ hybridization. Paraffin-embedded archival tissue from 245 patients was retrieved and assessed for Her-2/neu and topoisomerase IIα amplification/deletion by fluorescence in situ hybridization according to standard protocols. Relation to clinical data and survival was sought. A total of 245 cases were analyzed. Amplification for Her-2/neu was seen in 57 cases (23.3%), and for topoisomerase IIα in 12 cases (4.9%). Coamplification was found in 9 samples (3.7%), 3 cases (1.2%) showed amplification of topoisomerase IIα but not of Her-2/neu, and 48 samples (19.8%) displayed amplification for Her-2/neu but not for topoisomerase IIα. Correlation to the histologic type, the stage, or the grade could not be found. Only the amplification of topoisomerase IIα was associated with very poor outcome; survival of cases with amplification of Her-2/neu only was slightly lower than the mean overall survival (27.4 vs. 31.9 mo). Amplification of Her-2/neu and/or topoisomerase IIα is associated with poor overall survival. Amplification of topoisomerase IIα does not seem to be necessarily linked to Her-2/neu-amplification. However, independent determination of these 2 markers seems to be valuable for an individualized therapy of breast cancer patients.

Correlations of TOP2A gene aberrations and expression of topoisomerase IIα protein and TOP2A mRNA expression in primary breast cancer: a retrospective study of 86 cases using fluorescence in situ hybridization and immunohistochemistry

Our aim in this study was to assess the status of TOP2A gene aberrations (no change/amplification or deletion) and its correlations with topoisomerase IIα (Topo IIα) protein and TOP2A mRNA expression, respectively. TOP2A amplification, Topo IIα protein expression and TOP2A mRNA expression were assessed using samples of 86 cases of breast cancer by fluorescence in fluorescence in situ hybridization, quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. Twenty two (22.57%) had amplification/deletion of TOP2A gene. Twenty eight (32.56%) tumor samples were 17q polysomy or monosomy. Topo IIα protein was expressed in 57 cases (66.27%, 57/86): 22 cases (38.62%, 22/57) and 35 cases (61.40%, 35/57) had amplification/deletion and no change of TOP2A gene, respectively. These three groups showed significant differences by one-way analysis of variance (P < 0.001). The average Ct values of TOP2A mRNA expression in the tumors with deletion, amplification and no change of TOP2A gene were 27.00, 27.33 and 31.66, respectively. We demonstrated that the TOP2A gene was amplified or deleted in breast cancer, with a significant correlation with high expressions of Topo IIα protein and TOP2A mRNA expression. Ki-67 expression index (mean = 14.9) decreased significantly in cases wherein TOP2A gene had no change and Her2/neu protein expression was weakly positive (0-1+, P < 0.001).

Lack of prognostic relevance of Her-2/neu, topoisomerase IIα and EGFR in advanced ovarian carcinoma

Patients with advanced ovarian cancer (FIGO stage III) have a poor clinical prognosis. However, these patients show distinct differences in their survival time, possibly due to differing responses to chemotherapy and differing tumor biology. In contrast to histological subtype, grading and staging, which are known to affect a patient's prognosis, the impact of the human epidermal growth factor receptor 2 (Her-2/neu), topoisomerase IIα and epidermal growth factor receptor (EGFR) on survival remain inconclusive. Therefore, the aim of this study was to assess their impact on survival in a group of advanced ovarian cancer patients. Tissue microarrays were constructed from specimens of 243 patients. Gene copy and chromosome numbers were evaluated by fluorescence in situ hybridization (FISH) and protein expression by immunohistochemistry (IHC). Scoring for the latter was calculated by considering the percentage of positive tumor cells and the relative staining intensity. FISH results were evaluated by previously published recommendations and correlated with overall survival. Using IHC, 1.6% of the cases that were tested for Her-2/neu and topoisomerase IIα were strongly positive, and 12.3% were positive for EGFR. Using FISH, 4.4% amplifications and 2.1% polysomies for Her-2/neu were identified; topoisomerase IIα showed 2.2% amplifications, 0.4% deletions and 3.5% polysomies. We observed 10.8% high polysomies, but no amplification for EGFR. None of the results obtained by IHC or FISH correlated with overall survival. In general, Her-2/neu, topoisomerase IIα and EGFR may be prognostic factors in ovarian carcinomas. However, within this group of FIGO stage III patients, differences in gene aberration or protein expression were not able to predict differences in survival.

Tumor topoisomerase II alpha status and response to anthracycline-based neoadjuvant chemotherapy in breast cancer

OBJECTIVES

Individualized chemotherapy for breast cancer improves the outcome. Anthracyclines target the enzyme topoisomerase IIα (TOP2A). We set out to perform a retrospective study of the presence of gene abnormalities and the expression of TOP2A in a cohort of breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy.

METHODS

Forty-three patients with 45 breast cancers were treated with neoadjuvant docetaxel-epirubicin with/without capecitabine chemotherapy. The TOP2A status of the cancers, determined retrospectively by fluorescent in situ hybridization and immunohistochemistry, was analyzed in relation to the standard clinical and pathological data.

RESULTS

Clinically and pathologically complete remission (pCR) was achieved in 15 (33.3%) and 9 (20%) cases, respectively. The TOP2A gene was amplified in 2 human epidermal growth factor receptor 2 (HER2)-positive cancers (8%), and 32 (84.2%) overall exhibited TOP2A expression in >15% of the cells. The expression of TOP2A exhibited a strong correlation with the expression of Ki67 (R = 0.743, p < 0.001), and was negatively correlated with estrogen receptors (ER; R = 0.404, p = 0.012) and progesterone receptors (R = 0.430, p = 0.007). The expression of TOP2A was not related to the amplification of the TOP2A gene or the HER2 status of the tumor. The proportions of Ki67- and TOP2A-positive tumor cells were significantly reduced after chemotherapy (56.1 ± 23.6 vs. 19.0 ± 27.7%, p = 0.004, and 41.0 ± 27.9 vs. 12.7 ± 24.8%, p < 0.001, respectively). The development of pCR was related to a high grade (p = 0.054), ER negativity (p = 0.027) and high TOP2A expression (p = 0.037). The expression of TOP2A was an independent predictor of pCR (OR = 1.460, for every 10% increase, 95% CI: 1.016-2.096, p = 0.041). After a median follow-up time of 31.0 months, neither relapse-free survival nor overall survival was related to the tumor response.

CONCLUSIONS

TOP2A expression is a marker of the tumor's proliferation rate and sensitivity to anthracycline-based chemotherapy, and does not depend on the amplification of its gene.

Topoisomerase II alpha expression and the Ki-67 labeling index correlate with prognostic factors in estrogen receptor-positive and human epidermal growth factor type-2-negative breast cancer

BACKGROUND

Topoisomerase II alpha (Topo IIa) is involved in DNA replication and is a molecular target for anthracycline-based chemotherapy. The Ki-67 labeling index (LI) is an evaluation of tumor cell proliferation. The objective of this study was to evaluate relationships among Topo IIa expression, the Ki-67 LI, and prognostic factors in estrogen receptor (ER)-positive, human epidermal growth factor type-2 (HER2)-negative breast cancer.

MATERIALS AND METHODS

Seventy-one patients were diagnosed with ER-positive, HER2-negative breast cancer between July 2003 and December 2004. Formalin-fixed, paraffin-embedded tumor specimens were stained for Topo IIa expression and Ki-67 LI. We investigated the correlation of the level of Topo IIa expression and the Ki-67 LI with clinical factors such as age, tumor size, progesterone receptor status, nodal status, nuclear grade, and lymphovascular invasion (LVI).

RESULTS

Statistically significant differences were observed between Topo IIa overexpression, nuclear grade (p = 0.036), and LVI (p = 0.029). Topo IIa overexpression was statistically correlated with the Ki-67 LI (p < 0.0001). A statistically significant difference was observed between the Ki-67 LI and nuclear grade (p = 0.01). Survival analysis revealed the significant prognostic value of Ki-67 LI in patients with ER-positive, HER2-negative breast cancer (p = 0.003).

CONCLUSIONS

Ki-67 LI is a strong prognostic factor in ER-positive HER2-negative breast cancer. Topo IIa overexpression was significantly correlated with the Ki-67 LI, nuclear grade, and LVI. These findings suggest use of Topo IIa expression as a proliferation marker and a prognostic factor in ER-positive, HER2-negative breast cancer.

Tumour topoisomerase II alpha protein expression and outcome after adjuvant dose-dense anthracycline-based chemotherapy

There is a need for the selection of those breast cancers where benefit may be attained from the addition of an anthracycline to the adjuvant chemotherapy. The expression of topoisomerase II alpha (TOP2A) protein in 3 cohorts of breast cancers treated with adjuvant dose-dense anthracycline-based chemotherapy was determined retrospectively. The TOP2A status was analysed in relation with the other standard tumour features and the outcome. TOP2A IHC results were assessable in 106 patients: with a cut-off value of 15%, 48% of the tumours were classified as TOP2A-positive. The expression of TOP2A correlated with that of Ki67 (R = 0.532, p < 0.001) and a high grade (p = 0.04), but did not correlate with the proportion of ER- or PR-positive cells in the tumour. More tumors were TOP2A-negative among the ER- or PR-positive cancers than among the ER/PR-negative cancers (p = 0.021 and p = 0.002, respectively). After a median follow-up time of 64.5 months, 31 relapses (23.5%) and 23 deaths (17.4%) had occurred in 131 patients. The overall survival was longer in the TOP2A-positive cases than in the TOP2A-negative cases. The recurrence-free survival and the overall survival were significantly more favourable in the ER/PR-negative and TOP2A-positive tumours than in other subgroups. In a Cox proportional hazards model, the grade and TOP2A remained significant determinants in the ER/PR-negative subgroup. TOP2A positivity and grade 3 indicated a decrease in the risk of death with HR = 0.211 (95% CI: 0.042-1.05, p = 0.056) and HR = 0.216 (95% CI: 0.047-0.990, p = 0.048), respectively. A higher sensitivity to anthracycline-containing regimens is suggested in ER/PR-negative and TOP2A-positive cancers.

Molecular assays in breast cancer pathology

Recent advances in understanding the molecular pathology of breast cancer offer significant potential to identify patients who may benefit from adjuvant therapies. To date, few of these advances are utilised in a routine setting. We review molecular assays that are currently in use or are in the advanced stages of development, which may be used as predictive or prognostic biomarkers in breast cancer.The only widely used breast cancer molecular assay is in situ hybridisation (ISH) for human epidermal growth factor receptor 2 (HER2) gene amplification and we highlight key issues with the interpretation of this assay, with particular attention to the difficulties of the equivocal category. New molecular assays such as ISH for the topoisomerase II alpha (TOP2A) gene and for the aberrations in the copy number of the centromeric region of chromosome 17 are readily performed in a standard histopathology laboratory, but to date there are insufficient data to support their routine use. We also review the current data on two commercially available multigene expression assays, Oncotype DX and MammaPrint and discuss their potential use. Overall, while new molecular assays have significant potential to improve patient selection for therapy, well-performed histopathology with reliable interpretation of standard hormone and HER2 assays provides the most important predictive and prognostic information in early breast cancer.

Prognostic potential of topoisomerase IIα and HER2 in a retrospective analysis of early advanced breast cancer patients treated with adjuvant anthracycline chemotherapy

BACKGROUND

After surgery and anthracycline adjuvant treatment, about 60% of early advanced breast cancer patients develop recurrence. These differences in treatment outcome indicate the need to identify markers for risk of recurrence. The aim of this study was the retrospective analysis of relationship between tumour features (topoisomerase IIα (TOPOIIα), human epidermal growth factor receptor 2 (HER2), hormone receptors, cytokeratin (CK)5/6 expression and proliferation rate) and disease-free survival (DFS) of breast cancer patients treated with anthracyclines in adjuvant setting.

MATERIAL AND METHODS

The study was performed in the group of 172 patients (mean age: 52.8 years, T1-T2, N1-N2, M0). HER2, TOPOIIα, estrogen receptor (ER) and progesterone receptor (PgR) expression and proliferation rate were studied immunohistochemically. HER2 overexpression was confirmed by fluorescence in situ hybridisation (FISH). These data were correlated with 5-year DFS.

RESULTS

In univariate analysis, lower TOPOIIα expression (median value ≤ 11.9%) and tumour grade G1 + G2 were favourable prognostic factors. All tumours were classified into four subtypes: (1) lower TOPOIIα expression and G1 + G2, (2) lower TOPOIIα expression and G3, (3) higher TOPOIIα expression and G3, and (4) higher TOPOIIα expression and G1 + G2. In Cox multivariate regression analysis, tumour subtype distinguished by TOPOIIα expression and grade was independent prognostic factor for DFS. All patients (n = 52) with TOPOIIα lower expression and G1 + G2 tumours, survived 5 years without any evidence of disease.

CONCLUSION

The results suggest that lower TOPOIIα expression and lower tumour grade are favourable prognostic factors for early advanced breast cancer patients after adjuvant anthracycline chemotherapy.

Topoisomerase II alpha expression and the benefit of adjuvant chemotherapy for postoperative patients with non-small cell lung cancer

Background

Adjuvant chemotherapy has been shown to improve survival rates of postoperative patients with non-small cell lung cancer (NSCLC). Biomarkers could help select an appropriate chemotherapy for NSCLC patients or predict the efficacy of chemotherapy. The objective of this study was to explore the possible prognostic and predictive role of topoisomerase II alpha (TopIIα) expression level in postoperative NSCLC patients who received adjuvant chemotherapy.

Methods

Patients with stage I-III NSCLC, who underwent surgery in our hospital from January 2004 to December 2007 and who also received adjuvant chemotherapy after surgery, were analyzed in this study. Expression of TopIIα and Ki67 in paraffin-embedded tissues was detected by immunohistochemistry (IHC). The relationships between clinicopathological characteristics, chemotherapy regimens, the expression of biomarkers and disease free survival (DFS) were analyzed.

Results

TopIIα and Ki67 were highly expressed in 22.5% and 36.4% of the 151 patients, respectively. Univariate survival analysis showed that male sex (P = 0.036), non-adenocarcinoma (P = 0.004), earlier pathological TNM stage (P = 0.001) or pathological N stage (P < 0.001), and high expression of TopIIα (P = 0.012) were correlated with better DFS, whereas age, smoking history, different chemotherapy regimens, T stage and expression level of Ki67 were of no prognostic significance. Further stratified analysis showed that vinorelbine (NVB)-containing adjuvant regimens were generally associated with better DFS than regimens without NVB in patients with low TopIIα expression, though the difference was not statistically significant (P = 0.065). Pairwise comparisons for patients with low TopIIα expression indicated that the NVB-containing regimen was associated with better DFS than the docetaxel (TXT)-containing regimen (P = 0.047). COX multivariate analysis showed that pathological TNM stage, histological subtype and expression level of TopIIα to be independent of risk factors affecting DFS in postoperative NSCLC patients who received chemotherapy.

Conclusions

High TopIIα expression was discovered to be correlated with better DFS for postoperative NSCLC patients who received adjuvant chemotherapy. The NVB-containing chemotherapy regimen was more effective than the TXT-containing regimen in improving DFS in patients with low TopIIα expression. TopIIα could be considered to be an independent prognostic biomarker of DFS in postoperative NSCLC patients who received adjuvant chemotherapy.

Topo2α protein expression predicts response to anthracycline combination neo-adjuvant chemotherapy in locally advanced primary breast cancer

Background:

This study aimed to identify predictors of response to anthracycline-based chemotherapy (5-fluoro-uracil, epirubicin, cyclophosphamide (FEC)) in locally advanced primary breast cancer (LAPC).

Methods:

A total of 91 LAPC patients were treated with six cycles of FEC before surgery. Protein expression of nine biomarkers (topoisomerase2α (Topo2α), ER, PR, HER2, Ki67, p53, EGFR, CK5/6 and CK14) was assessed in pre-chemotherapy core biopsies using immunohistochemistry (IHC) and results correlated with clinical and pathological response.

Results:

Clinical (cCR) and pathological (pCR) complete response were seen in 34.1% (n=31) and 20% (n=18), respectively. Pathological complete response was concordant with cCR in 14/31 cases; in four cases of cPR with palpable residual breast tumours, histology showed fibrous tissue only (pCR). On univariate analysis, pre-chemotherapy high expression of Topo2α protein (P=0.031), and negativity for ER and EGFR (P=0.001 and P=0.005, respectively) correlated with pCR. Positivity for p53 also showed significance (P=0.015), whereas basal phenotype, HER2, and all the clinicopathological variables of LAPC included in this study did not show significant correlation with response. On multivariate analysis, Topo2α expression had the strongest correlation with pCR (P=0.021) followed by EGFR (P=0.044).

Conclusion:

The study suggests that pre-chemotherapy Topo2α protein expression measured by IHC strongly correlates with pathological CR to neo-adjuvant anthracyclines in this group of LAPC studied.