In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 15_suppl ( 2017-05-20), p. e23039-e23039
Abstract:
e23039 Background: It is particularly important to provide precise therapies and understand tumor heterogeneity based on the molecular typing of gene expression. Yet the landscape of somatic mutations in different subtypes of advanced breast cancer (ABC) is largely undetermined. Methods: Overall, 100 blood samples were obtained from 100 advanced female breast cancer patients who underwent therapy at Cancer Hospital, Chinese Academy of Medical Sciences from March 2015 to September 2016. Mutations in 1021 tumor-related genes in ctDNA was assayed by gene-panel target-capture next-generation sequencing. Results: Somatic genomic alterations in ctDNA including copy number variants and point mutations were identified in 96 of 100 patients (96.0%). The number of somatic mutations varied markedly between individual patients (mean 2.9, range1-31). No difference was found between four subtypes for the number of somatic mutations. However, the mean number of somatic mutations was higher in age at 40-50 year than patients over age 60 ( p= 8.46 vs 3.88; p= 0.01). Results from multivariate analyses showed that the number of somatic mutations was increased with the number of endocrine therapy line ( p= 0.007). TP53 and PIK3CA were two most frequently mutated genes detected in ctDNA of 100 patients which were recurrently detected in 43 (43.0%) and 32 (32.0%) patients, respectively. ESR1/PIK3CA were more prevalent in HR+ cancers ( p= 0.007, 0.025 respectively). NOTCH1 are more frequently detected in HER2- group than in HER2+ patients (15.63% vs 2.94%; p= 0.033). In multiple logistic regression analysis indicated that pathological grade, tumour size at diagnosis and PR statue were positive associated with PIK3CA mutations. Multiple regression analysis also revealed that ki-67, metastatic at diagnosis, number of metastatic sites, number of endocrine line were associated with ESR1 mutations. Conclusions: The results revealed that different subtypes ABC have their own genetic alterations features. Certain gene mutations may be related to clinical treatment especially endocrine therapy.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2017.35.15_suppl.e23039
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2017
detail.hit.zdb_id:
2005181-5
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