Topoisomerase II-α (topoII) and HER2 amplification in breast cancers and response to preoperative doxorubicin chemotherapy

Purpose Approximately 35% of HER2-amplified breast cancers have coamplification of the topoisomerase II-alpha (TOP2A) gene encoding an enzyme that is a major target of anthracyclines. This study was designed to evaluate whether TOP2A gene alterations may predict incremental responsiveness to anthracyclines in some breast cancers. Methods A total of 4,943 breast cancers were analyzed for alterations in TOP2A and HER2. Primary tumor tissues from patients with metastatic breast cancer treated in a trial of chemotherapy plus/minus trastuzumab were studied for amplification/deletion of TOP2A and HER2 as a test set followed by evaluation of malignancies from two separate, large trials for changes in these same genes as a validation set. Association between these alterations and clinical outcomes was determined. Results Test set cases containing HER2 amplification treated with doxorubicin and cyclophosphamide (AC) plus trastuzumab, demonstrated longer progression-free survival compared to those treated with AC alone (P = .0002). However, patients treated with AC alone whose tumors contain HER2/TOP2A coamplification experienced a similar improvement in survival (P = .004). Conversely, for patients treated with paclitaxel, HER2/TOP2A coamplification was not associated with improved outcomes. These observations were confirmed in a larger validation set, where HER2/TOP2A coamplification was again associated with longer survival when only anthracycline-containing chemotherapy was used for treatment compared with outcome in HER2-positive cancers lacking TOP2A coamplification. Conclusion In a study involving nearly 5,000 breast malignancies, both test set and validation set demonstrate that TOP2A coamplification, not HER2 amplification, is the clinically useful predictive marker of an incremental response to anthracycline-based chemotherapy. Absence of HER2/TOP2A coamplification may indicate a more restricted efficacy advantage for breast cancers than previously thought.

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DNA Topoisomerase II-α and Cyclin A Immunoexpression in Meningiomas and Its Prognostic Significance

Archives of Pathology & Laboratory Medicine ◽

10.5858/2002-126-1079-dtiaca ◽

2002 ◽

Vol 126 (9) ◽

pp. 1079-1086

Author(s):

Andrey Korshunov ◽

Lyudmila Shishkina ◽

Andrey Golanov

Keyword(s):

Topoisomerase Ii ◽

Tumor Grade ◽

Cyclin A ◽

Close Correlation ◽

Hazard Ratio ◽

Benign Tumors ◽

Ki 67 ◽

Dna Topoisomerase ◽

Proliferative Markers ◽

Topoisomerase Ii Α

Abstract Context.—Routine pathologic examination cannot distinctively predict the clinical course of meningiomas because even histologically benign tumors may recur after gross total resection. Therefore, numerous efforts have been made to evaluate the meningioma growth fraction and its prognostic value. However, a universally applicable proliferative marker for meningioma outcome is not yet a reality. Objective.—To investigate the prognostic utility of 3 proliferative markers, namely, Ki-67, DNA topoisomerase II-α (topoII), and cyclin A in a representative series of intracranial meningiomas. Design.—Two hundred sixty-three adult patients with intracranial meningiomas (208 benign, 42 atypical, and 13 anaplastic) were studied retrospectively. Tumor specimens were immunohistochemically examined with antibodies to Ki-67 (MM-1), topoII, and cyclin A. A computerized color image analyzer was used to count immunostained nuclei. Results.—The topoII and cyclin A scores exhibited a close correlation with Ki-67 immunostaining. Significant differences between the indices for all 3 markers were noted among the 3 grades of meningiomas. The scores for all 3 markers were significantly different between recurrent and nonrecurrent meningiomas, including benign tumors that were treated with gross total resection. Recurrence-free survival was significantly reduced for cases with a Ki-67 labeling index (LI) of 4.4% or greater, a topoII LI of 3.2% or greater, and a cyclin A LI of 3.1% or greater. Multivariate analysis revealed that the risk of recurrence for the entire meningioma cohort was significantly associated with tumor grade (hazard ratio = 2.7; P = .004), topoII LI of 3.2% or greater (hazard ratio = 5.5; P < .001), and a cyclin A LI of 3.1% or greater (hazard ratio = 2.4; P = .01). Conclusions.—There is a close correlation in the expression of these 3 proliferative markers in meningiomas, and all of the markers showed a significant association with tumor grade, recurrence rate, and recurrence-free survival. Consequently, in addition to Ki-67, immunoexpression of topoII and cyclin A is available for predicting meningioma recurrence. Moreover, the topoII and cyclin A staining scores were found to be more sensitive predictors for meningioma progression than Ki-67 and, therefore, either of these 2 markers may prove to be clinically informative and useful.

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