[Show abstract][Hide abstract] ABSTRACT: Secretory breast cancer (SBC) is a rare entity characterised by indolent clinical behaviour, distinctive histological features and the presence of a recurrent chromosomal translocation t(12;15)(p13;q25), leading to the formation of the ETV6-NTRK3 fusion gene.
To describe the molecular genetic features of a case of SBC which harbours a duplication of the t(12;15) translocation.
Tiling path array comparative genomic hybridisation (aCGH) analysis and fluorescence in situ hybridisation (FISH) using in-house-generated probes for ETV6, NTRK3 and the fusion genes, centromeric probes for chromosomes 12 and 15, and a commercially available split-apart ETV6/NTRK3 probe.
FISH revealed the presence of a duplication of the translocation t(12;15), which resulted from the gain of one copy of the derivative chromosome der(15)t(12;15), retention of one normal copy of both ETV6 and NTRK3 genes and deletion of the derivative chromosome der(12)t(12;15). Consistent with FISH findings, aCGH revealed copy number gains of ETV6 and NTRK3 and deletions encompassing the regions centromeric to ETV6 and telomeric to NTRK3. Additional regions of copy number changes included gains of 10q21, 10q26.3, 12p13.3-p13.31 15q11-q25.3 and 16pq and losses of 6q24.1-q27, 12p13.2-q12 and 15q25.3-q26.3.
To the best of our knowledge, this is the first time a carcinoma has been shown to harbour a duplication of the ETV6-NTRK3 translocation. The presence of an additional copy of the derivative chromosome der(15)t(12;15) coupled with deletion of the other derivative der(12)t(12;15) in the modal population of cancer cells suggests that this was either an early phenomenon or conferred additional growth advantage on neoplastic cells.
[Show abstract][Hide abstract] ABSTRACT: Secretory breast carcinoma is a rare breast cancer with indolent clinical behavior. Recent research showed that secretory breast carcinoma belongs to the phenotypic spectrum of basal-like breast carcinomas. In this study, a clinicopathological and immunophenotypic analysis of secretory breast carcinomas from 15 Chinese patients was conducted. This patient group consisted of 2 males and 13 females, with ages ranging from 10 to 67 years old (median, 36 years old). All patients presented with a painless and firm mass. Tumor size ranged from 10 to 55 mm. Most tumors were located in the outer upper quadrant of the breast. Two patients (2 of 13, 15%) displayed positive axillary lymph nodes. At the microscopic level, the presence of intracellular and extracellular secretory material was the most remarkable feature. Most cases showed mild dysplasia cytologically. All cases were negative for estrogen receptor, progesterone receptor and HER2. The expression rate of the basal-like marker (CK5/6 or epidermal growth factor receptor) was 87% (13 of 15). The basal-like phenotype was identified in 13 cases (87%). Follow-up time ranged from 10 to 55 months (median, 19 months). None of the cases had evidence of recurrence and metastasis. Our study reveals that secretory breast carcinoma is a distinct subset of invasive breast carcinoma, with expression of basal-like markers. It should be noted that secretory breast carcinoma is different from conventional basal-like breast carcinomas. Future studies are required to further understand the prognostic significance of the basal-like markers expression in secretory breast carcinomas.
Modern Pathology 12/2011; 25(4):567-75. DOI:10.1038/modpathol.2011.190 · 6.36 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.