488 - HISTOPATHOLOGICAL AND EPIDEMIOLOGICAL PROFILE OF PATIENTS WITH INVASIVE LOBULAR CARCINOMA OF THE BREAST TREATED AT A REFERENCE HOSPITAL

Resumo

Introduction: Breast cancer is the most common and the second leading cause of cancer death among women worldwide.
It is known that invasive breast carcinomas are the most frequent, with 75% of them subclassified as invasive ductal carcinoma (IDC), 15% as lobular, and 10% as special subtypes. Classic invasive lobular carcinoma (ILC) is characterized by
discohesive tumor cells, low mitotic rate, invading singly or in single concentric rows around ducts, and associated with
loss of E-cadherin protein expression. Objective: This study evaluated the histopathological and epidemiological profiles
of patients with ILC of the breast treated at a reference hospital from January 2018 to December 2020, in Fortaleza, CE.
Methods: This research is characterized as a retrospective, analytical, descriptive, and quantitative, using data from the
electronic medical records of patients treated at the Hospital Haroldo Juaçaba (HHJ),; data collection was based on a protocol developed by the researchers, which contained the following variables: sex, age, clinical presentation, alterations in
imaging examinations, clinical and pathological staging, histological grade and subtype, presence of molecular markers
estrogen receptor (ER), progesterone receptor (PR), HER2 (human epidermal growth factor 2), KI-67 (proliferative index),
locoregional and systemic therapy of choice, and response to neoadjuvant systemic therapy. Results: It was observed
that all patients (119) were female, with a predominant age between 50 and 59 years. A significant number of patients had
clinical changes that contributed to the diagnosis; among them, the presence of nodules was the most frequent (92.2%).
As for imaging examinations, mammography showed lower rates of ILC detection when compared to ultrasound examinations (69.7% and 75.6%, respectively). Most patients were identified at stage IIA in the clinical and pathological evaluations (42.9% and 23.5%, respectively). On histology, 58% of the carcinomas were grade II, while 92.4% belonged to the classic subtype. There was also a high level of positivity for markers ER (95%) and PR (81.5%), suggesting the prevalence of the
luminal-like molecular profile (95%). In the context of surgical interventions, 62.2% of patients underwent mastectomy
and 45.4% underwent only sentinel lymph node biopsy in the axillary approach. Regarding neoadjuvant therapy, 70.8%
of the patients presented regression in the tumor stage. Endocrine therapy was used by 78.2% of the women in the adjuvant. Conclusion: Invasive lobular neoplasms have distinct characteristics, with a unique clinical and histopathological
profile. The lack of studies that can be used to conduct cases and treat this pathology is highlighted, thus reinforcing the
importance of this research.