Introduction: Phyllodes tumor (PT) of the breast, particularly malignant phyllodes tumor (mPT), is a rare fibroepithelial neoplasm. A complex diagnosis is based on pathologic, radiologic, and clinical findings, with controversies about what is the best therapeutic strategy. Objective: Our objective was to provide an overview of the clinical, pathologic, and therapeutic aspects of this rare tumor. Conclusions: mPT is a rare presentation of breast cancer and a challenge in clinical practice. A multidisciplinary approach should take into account some aspects like pathogenic mutations and hereditary syndromes. Oncologic surgery is the fundamental approach, and the use of adjuvant therapies is still controversial due to the lack of clinical trials. Treatment recommendations should be individualized according to patient risk and preferences. Prospective studies are fundamental to clarifying the best treatment for these tumors.

The aim of our study was to investigate basal phenotype in a series of triple-negative (estrogen and progesterone receptors-negative and HER2-negative) invasive mammary carcinomas. We selected 140 previously tested triple-negative tumors. Clinical, histopathological and survival data were obtained. A tissue microarray containing 2 cylinders from each tumor was constructed and immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR), HER2, cytokeratins (CK) 5 and 14, EGFR, p63, and p53 was performed. We considered basal like-cancers (BLC) those tumors that were ER/PR/HER2-negative and CK5-positive. We found 105 cases of BLC from 140 triple-negative tumors (frequency=75.0%). The mean age at diagnosis was 54.8 years-old and 34.3% were premenopausal women. The majority of tumors were high grade (83.7%) and of ductal/no-special-type (80.8%). Triple-negative tumors showed immunoreactivity for CK5 (75.0%), CK14 (29.0%), EGFR (28.6%), p63 (28.6%), and p53 (67.1%). Tumor size larger than 5cm was observed in 41 cases (39.0%) and axillary metastases were detected in 61 patients (59.2%). Follow-up was recorded for 89 patients (mean=51 months): 45 patients (50.5%) with no evidence of disease; 6 patients (6.7%) were alive with disease; and 38 patients (42.6%) died of the disease. Relapse was detected in 42 women (47.1%), lungs, brain, and bones being the most common sites of metastasis. The mean overall survival was 36 months and the mean disease-free interval was 28 months. Our findings confirmed that BLC are poor prognosis and highly-frequent carcinomas among triple-negative tumors, similar to data previously reported in North American and European patients.

Background: Triple‐negative breast cancer (TNBC) is the neoplasia most associated with BRCA1 germline pathogenic variants (PV) and is more likely to develop metastases than the other breast cancer (BC) subtypes, mainly in the lungs and the central nervous system (CNS). Recently, BRCA2 carriers were shown to have a higher risk for developing CNS metastases. However, the patterns of recurrence and metastases of BRCA2 carriers with TNBC are unknown.Methods: TNBC patient data attending the A.C. Camargo Cancer Center, from 1998 through 2020, were verified either by medical records or by BRCA1/2 genetic testing carried out. Multivariable logistic regression models were fit to the data to assess the independent factors for bone and CNS metastases. Adjustment was done using all independent variables with p < 0.2 in the univariable Cox model to describe the relationship between the independent variables until time of death.Results: A total of 388 TNBC patients were evaluated. We identified PV in BRCA1/2 genes in 21% (82/388), being 17.7% (69/388) in BRCA1 and only 3.3% (13/388) in BRCA2. A total of 120 patients (31%) developed distant metastases. Bone or CNS metastases were observed in 40% and 60% of BRCA2 PV carriers (p = 0.155), respectively. The BRCA2 carriers tended to have a higher likelihood of developing bone metastases (OR, 4.06; 95% CI, 0.82–20.01; p = 0.085), when compared to BRCA1 carriers (OR, 0.6; 95% CI, 0.12–2.87; p = 0.528). BRCA2 carriers had an OR of 1.75 (95% CI, 0.33–9.14; p = 0.503) for CNS metastasis development, while BRCA1 carriers had an OR of 0.72 (95% CI, 0.23–2.23; p = 0.574).Conclusions: Patients with TNBC and PV in the BRCA2 gene had higher frequencies of secondary bone involvement and CNS in the course of the disease. However, the BRCA2 PV did not represent an independent outcome predictor of metastases and overall survival. Efforts to increase the number of BRCA2 carriers among TNBC patients are crucial for determining their risk of developing bone and CNS metastases compared to BRCA2 noncarriers.

Currently, breast cancer (BC) is the most common cancer among women worldwide, accounting for more than 2.3 million cases annually¹ 1. World Health Organization. WHO launches new roadmap on breast cancer [Internet]. 2024. [cited on 2023 Jul 17]. Available from: https://www.who.int/news/item/03-02-2023-who-launches-new-roadmap-on-breast-cancer https://www.who.int/news/item/03-02-2023... , and the leading cause of cancer death in women² 2. Anderson BO, Ilbawi AM, Fidarova E, Weiderpass E, Stevens L, Abdel-Wahab M, et al. The global breast cancer initiative: a strategic collaboration to strengthen health care for non-communicable diseases. Lancet Oncol. 2021;22(5):578-81. https://doi.org/10.1016/S1470-2045(21)00071-1 https://doi.org/10.1016/S1470-2045(21)00... .