Anti-PGR monoclonal antibody, clone 2C22

Many patients with ER+ HER2- primary breast cancer are being deferred from surgery to neoadjuvant endocrine therapy (NeoET) during the COVID-19 pandemic. We have collated data from multiple international trials of presurgical endocrine therapy in order to provide guidance on the identification of patients who may have insufficiently endocrine-sensitive tumors and should be prioritised for early surgery or neoadjuvant chemotherapy rather than NeoET during or in the aftermath of the COVID-19 pandemic for safety or when surgical activity needs to be prioritized. For postmenopausal patients, our data provide strong support for the use of ER and PgR status at diagnosis for triaging of patients into three groups in which (taking into account clinical factors): (i) NeoET is likely to be inappropriate (Allred ER <6 or ER 6 and PgR <6) (ii) a biopsy for Ki67 analysis (on-treatment Ki67) could be considered after 2-4 weeks of NeoET (a: ER 7 or 8 and PgR <6 or b: ER 6 or 7 and PgR >= 6) or (iii) NeoET is an acceptable course of action (ER 8 and PgR >= 6). Cut-offs for percentage of cells positive are also given. For group (ii), a high early on-treatment level of Ki67 (>10%) indicates a higher priority for early surgery. Too few data were available for premenopausal patients to provide a similar treatment algorithm. These guidelines should be helpful for managing patients with early ER+ HER2- breast cancer during and in the aftermath of the COVID-19 crisis.

Objectives: Tumor-associated antigens (TAAs) are frequently overexpressed in several cancer types. The aim of this study was to investigate the expression of TAAs in breast cancer. Material and methods: A total of 250 selected invasive breast cancers including 50 estrogen receptor (ER)-positive (Luminal B like), 50 triple-negative (TN), 50 ER-positive lobular type, 50 ER- and progesterone receptor (PgR)-positive (Luminal A like) and 50 cerbB2-positive breast cancers, were assessed for New York esophageal squamous cell carcinoma-1 (NY-ESO-1), Wilms tumor antigen (WT-1) and PReferentially expressed Antigen of MElanoma (PRAME) antigen expression by immunohistochemistry (IHC). Results: A significantly higher expression of cancer testis (CT)-antigens NY-ESO-1 and WT-1 antigen was detected in TN breast cancers compared with ER-positive tumors. NY-ESO-1 overexpression (score 2 + and 3+) assessed by monoclonal and polyclonal antibodies was detected in 9 (18%) TN cancers as compared to 2 (4%) ER-positive tumors (p = 0.002). WT1 over-expression (score 2 + and 3+) was confirmed in 27 (54%) TN tumor samples as compared to 6 (12%) ER-positive (p < 0.0001). PRAME overexpression (score 2 + and 3+) was detected in 8 (16%) HER2 positive tumor samples as compared to no TN and ER-positive cancers (p = 0.0021). Conclusions: NY-ESO-1 and WT1 antigens are overexpressed in TN breast cancers. Because of the limited therapeutic options for this patient subgroup, CT antigen-based vaccines might prove to be useful for patients with this phenotype of breast cancer. (C) 2019 The Authors. Published by Elsevier Ltd.