HR negative

Chemotherapy was the first-line regimen in 83 of 162 patients (51%), endocrine monotherapy in 55 of 162 (34%), and trastuzumab-pertuzumab-taxane or cyclin-dependent kinase 4 and 6 inhibitor-based regimens in eight of 162 (5%). 87534309); Center for Global Health at the United States-National Cancer Institute at the National Institutes of Health (contract award No. HHSN2612010000871/NO2-PC-2010-00087); Fogarty International Center, NIH, HHS; and Susan G. Komen for the Cure; in Argentina, Instituto Nacional del Cáncer (Ministry of Health), Fundación Argentina de Nanotecnología, Agencia Nacional de Promoción Científica y Tecnológica, CONICET (Ministry of Science, Technology, and Productive Innovation); Brazil, Ministério da Saúde (Ministry of Health); Chile, Instituto de Salud Pública (Public Health Institute) and Ministerio de Salud (Ministry of Health); and Mexico, Consejo Estatal de Ciencia y Tecnología de Jalisco (COECYTJAL) and Universidad de Sonora (University of Sonora).

In patients with HER2-positive breast cancer treated with pertuzumab-based neoadjuvant therapy, treatment response appears to be primarily influenced by clinicopathological and treatment-related factors rather than systemic inflammatory status. Peripheral blood inflammatory biomarkers derived from routine laboratory parameters showed limited value in predicting pCR in this setting.

This retrospective single-center study included 75 patients with HER2-positive invasive breast cancer treated with neoadjuvant chemotherapy plus dual anti-HER2 blockade (trastuzumab and pertuzumab). Given the modest discriminative performance and lack of external validation, these findings should be interpreted cautiously. Further validation in larger independent cohorts is required before the score can be considered for clinical stratification or implementation.

Our findings provide evidence of BRCA1 epigenetic silencing in breast tumours from African women, particularly within aggressive hormone receptor-negative subtypes. These results suggest that BRCA1 promoter methylation may represent a clinically informative biomarker for patient stratification and highlight the importance of validation in larger, population-representative cohorts before clinical translation.

An SMI index < 1.8, HER-2 positivity, and complete response on US and MRI are independent predictors of pCR after NAC. Combining SMI with multimodal imaging significantly improves predictive accuracy.

P2, N=36, Not yet recruiting, Laura Huppert, MD, BA | Trial completion date: Jun 2029 --> Sep 2029 | Trial primary completion date: Jun 2029 --> Sep 2029

We report a 51-year-old woman with prior hormone receptor-negative, human epidermal growth factor receptor 2-positive breast invasive ductal carcinoma (bilateral mastectomy, adjuvant trastuzumab/pertuzumab, radiation) who developed abrupt painful erythematous nodules of both legs and progressive polyarthralgia of the hands, knees, and ankles. Coordinated multidisciplinary care, oncology-directed chemotherapy, interventional pain management, and psychological support, improved pain control and mobility. This case adds to the limited pancreatitis, panniculitis, and polyarthritis literature and highlights that absent gastrointestinal symptoms can delay diagnosis; early recognition and collaborative management are essential in malignant pancreatitis, panniculitis, and polyarthritis presentations.

P2, N=46, Active, not recruiting, Virginia Commonwealth University | Trial completion date: Mar 2026 --> Mar 2027

Nodal positivity rates are substantial for T1-T2 HER2+ and triple-negative tumors, even for T1a/b tumors. Among T1c tumors, HR-HER2+ subtype and age of 50 years or younger independently predicted increased nodal positivity, supporting NST especially for these patients.

Compared with IHC 3+ IDC, IHC 2+/FISH+ IDC demonstrated lower pCR rates and inferior RFS in hormone receptor-negative subset following neoadjuvant trastuzumab/ pertuzumab-containing therapy. Pathologic response correlated inversely with HER2/CEP17 ratio and HER2 copy number. Reassessment of HER2 expression with more sensitive quantitative methods, particularly in IHC 2+/FISH+ tumors, may improve therapeutic stratification.

sTILs vary markedly across breast cancer subtypes and correlate with aggressive pathological features, particularly TNBC, high-grade, hormone receptor negativity, and high proliferative index. Incorporating standardized sTIL assessment into routine reporting may help identify tumors with active immune microenvironments.

Given that our cases were identified in a relatively short time period, it is likely that GLI1-rearranged tumours are more common in the female genital tract than is realised and a high index of suspicion is required to initiate appropriate testing and establish the diagnosis. In the absence of readily available appropriate molecular testing, GLI1 immunohistochemistry can serve as an acceptably accurate surrogate biomarker for GLI1 rearrangement, since we found that GLI1 immunohistochemistry showed strong, diffuse nuclear staining in 6 GLI1-rearranged gynaecologic tumours stained for this study, whereas this was consistently negative, or at most weak/focal, in an array of 135 morphologic mimics.