TROP2, androgen receptor, and PD-L1 status in histological subtypes of high-grade metaplastic breast carcinomas.
Histopathology
; 82(5): 664-671, 2023 Apr.
Article
em En
| MEDLINE
| ID: mdl-36527253
ABSTRACT
AIMS:
High-grade metaplastic breast carcinoma (HG-MBC) is a rare subtype of invasive breast carcinoma, mostly triple-negative. Metaplastic carcinomas are less responsive to neoadjuvant chemotherapy and are associated with a worse outcome than invasive carcinomas of no special type.METHODS:
Clinicopathological characteristics and immunophenotype were retrospectively assessed in a series of 65 patients diagnosed with HG-MBC between 2005 and 2017 at the Curie Institute (antibody panel oestrogen receptor [ER], progesterone receptor [PR], androgen receptor [AR], human epidermal growth factor receptor 2 [HER2], programmed death ligand-1 [PD-L1], and trophoblast cell surface antigen 2 [TROP2]).RESULTS:
The median age at diagnosis was 59.5 years. Six (9%) patients had metastatic disease at diagnosis. Among the nonmetastatic patients receiving neoadjuvant therapy, 26% (5/19) achieved pathological complete response. Most tumours were pT1/pT2 (77%) and 12% were pN+. Histological subtypes (mixed, squamous, mesenchymal, and spindle cell) were 40%, 35.5%, 15.5%, and 9%, respectively. Tumour-infiltrating lymphocytes were low or moderate except when squamous differentiation was present. Most tumours were triple-negative (92%). AR and TROP2 were positive in 34% and 85% of the cases, respectively. PD-L1 was positive in tumour cells in 18% (cutoff 1% of positive tumour cells) of the cases and in tumour-infiltrating immune cells in 40% (cutoff 1% of tumour area) of the cases. Notably, spindle cell and mesenchymal metaplastic breast carcinomas were mostly PDL1-negative. Lastly, 21 (32.3%) cases were HER2-low, all being HER2 1+, with no HER2 2+.CONCLUSION:
Metaplastic breast carcinoma could benefit from tailored therapeutic strategies adapted to the phenotypic specificities of histological subtypes.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
Carcinoma de Células Escamosas
Limite:
Female
/
Humans
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Middle aged
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article