Abstract PO5-17-02: Triple-negative breast cancer as an untraceable tumor compared to other immunohistochemical subtypes: a cross-sectional study

Abstract

Abstract Objective: To compare the form of presentation at diagnosis of triple negative breast tumors with other immunohistochemical subtypes, in relation to clinical examination or imaging examination. Methods: This is a cross sectional study that evaluated data related to the presentation of breast carcinomas at diagnosis (clinical examination or screening imaging examination findings), immunohistochemical subtype, histological grade and tumor size, in diagnosed and referred patients. for the Mastology service at Hospital São Paulo – Unifesp, in São Paulo – Brazil, in the period between 2012 and 2021, by analyzing data from the medical records of these patients. Results: Among the 699 invasive carcinomas diagnosed, 246 patients were diagnosed with luminal profile A (35.2%), 257 luminal B (36.8%), 58 luminal B HER-2+ (8.3%), 26 HER-2 enriched (3.7%) and 112 triple negative (16%). Triple negative carcinomas had a higher rate of diagnosis by clinical examination (86.6%), 6.65 times more likely to be diagnosed by clinical examination than luminal A, in addition to having a larger lesion. The triple negative and HER-2 enriched subtypes presented the worst scenarios of clinical stage at diagnosis. Among the tumors diagnosed by screening examination, those belonging to the luminal A were associated with nodules seen on imaging (in 45.1%) and the subtypes luminal B and luminal B HER-2+ with the appearance of microcalcifications. There were no cases of triple negatives involving microcalcifications in our sample. Asymmetries were more common in images of luminal B HER-2+ tumors. In the multivariate analysis, it was observed that only the histological grade and the Ki-67 value are related to the form of diagnosis. Tumors with histological grade 2 or 3 are more likely to be diagnosed by clinical examination and not be traceable in relation to histological grade 1. As for Ki-67, its increase of 1 percentage point leads to an increase of 1.3% in the chance finding on physical examination. There was no correlation of hormone receptors and HER-2 with the chance of the tumor not being screenable. Conclusions: triple negative subtype breast carcinomas present a higher risk of diagnosis by clinical examination compared to other immunohistochemical subtypes and, therefore, tend not to be traceable. Parameters such as high Ki-67 and histological grade correlate with this trend. Citation Format: Morgana Silva, Afonso Nazário, Vanessa Sanvido. Triple-negative breast cancer as an untraceable tumor compared to other immunohistochemical subtypes: a cross-sectional study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-17-02.