Evaluation of Antitumoral activity of bone targeted drugs/conventional chemotherapies and identification of biomarkers for the selection of patients with breast cancer for the bone targeted therapy in adjuvant setting

Bone metastases are responsible for different clinical complications defined as skeletal-related events (SREs) such as pathologic fractures, spinal cord compression, hypercalcaemia, bone marrow infiltration and severe bone pain requiring palliative radiotherapy. The general aim of these three years research period was to improve the management of patients with bone metastases through two different approaches of translational research. Firstly in vitro preclinical tests were conducted on breast cancer cells and on indirect co-colture of cancer cells and osteoclasts to evaluate bone targeted therapy singly and in combination with conventional chemotherapy. The study suggests that zoledronic acid has an antitumor activity in breast cancer cell lines. Its mechanism of action involves the decrease of RAS and RHO, as in osteoclasts. Repeated treatment enhances antitumor activity compared to non-repeated treatment. Furthermore the combination Zoledronic Acid + Cisplatin induced a high antitumoral activity in the two triple-negative lines MDA-MB-231 and BRC-230. The p21, pMAPK and m-TOR pathways were regulated by this combined treatment, particularly at lower Cisplatin doses. A co-colture system to test the activity of bone-targeted molecules on monocytes-breast conditioned by breast cancer cells was also developed. Another important criticism of the treatment of breast cancer patients, is the selection of patients who will benefit of bone targeted therapy in the adjuvant setting. A retrospective case-control study on breast cancer patients to find new predictive markers of bone metastases in the primary tumors was performed. Eight markers were evaluated and TFF1 and CXCR4 were found to discriminate between patients with relapse to bone respect to patients with no evidence of disease. In particular TFF1 was the most accurate marker reaching a sensitivity of 63% and a specificity of 79%. This marker could be a useful tool for clinicians to select patients who could benefit for bone targeted therapy in adjuvant setting.

Small molecules exploiting emerging therapeutic opportunities for breast cancer treatment

Among the different types of breast cancer (BC), the estrogen receptor positive (ER+) subtype, which requires estrogens for its growth and proliferation, is the most common, while triple negative BC, characterized by the absence of ER, progesterone receptor and human epidermal growth factor receptor 2, often leads to poor prognosis. First-line therapies for the treatment of ER+ BC act either by suppressing estrogen production, through the inhibition of aromatase (AR) enzyme, or by blocking estrogen prooncogenic activity, via the modulation/degradation of ERs. The serious side effects and the intrinsic or acquired resistance phenomena that arise with prolonged use of these drugs limit their therapeutic application, stimulating the search for new strategies to face this disease. In this context, the development of dual acting aromatase inhibitors, able to target both the orthosteric and the recently identified allosteric pockets of AR could be an opportunity to fight ER+ BC. Another promising strategy could be the development of multitarget compounds, targeting both AR and ERs. In this scenario, here we designed and synthesized two series of new xanthones or more flexible benzophenones as potential dual acting aromatase inhibitors. Moreover, inspired from tamoxifen metabolites and a literature compound endowed with activity on both AR and ER, different structurally related series of potential multitarget compounds were developed. The biological results showed that some of the new molecules were promising candidates for further development. It was recently observed that the lately discovered histamine H4 receptor is expressed in human breast tissue, displaying a key role in biological processes mediated by histamine such as cell proliferation, senescence, and apoptosis in malignant cells, representing a potential target in triple negative BC. Thus, a broad series of methyl quinazoline sulfonamides, carrying different functional groups on the sulfonamide moiety, were designed and synthesized as potential H4 receptor ligands.

Phenotypic and molecular investigation of circulating tumor cells (CTCs) isolated from breast cancer patients at single cell resolution

Despite the paramount advances in cancer research, breast cancer (BC) still ranks one of the leading causes of cancer-related death worldwide. Thanks to the screening campaign started in developed countries, BC is often diagnosed at early stages (non-metastatic BC, nmBC), but disease relapse occurrence even after decades and at distant sites is not an uncommon phenomenon. Conversely, metastatic BC (mBC) is considered an incurable disease. The major perpetrators of tumor spread to secondary organs are circulating tumor cells (CTCs), a rare population of cells detectable in the peripheral blood of oncologic patients. In this study, CTCs from patients diagnosed with luminal nmBC and mBC (hormone receptor positive, Human Epidermal Growth Factor Receptor 2 (HER2) negative) were characterized at both phenotypic and molecular levels. To better understand the molecular mechanisms underlying their biology and their metastatic potential, next-generation sequencing (NGS) analyses were performed at single-cell resolution to assess copy number aberrations (CNAs), single nucleotide variants (SNVs) and gene expression profiling. The findings of this study arise hints in CTC detection, and pave the way to new application in CTC research.

Omission of axillary clearance in patients with early breast cancer and positive sentinel node biopsy treated with conservative surgery: application of the ACOSOG Z011 trial in clinical practice

Background: Axillary lymph node dissection (ALND) in presence of sentinel lymph node (SLN) metastases has been the standard in breast cancer (BC) patients for many years. Today, after the publication of the ACOSOG Z0011 trial, ALND is a procedure restricted to a dwindling group of patients with a clearly metastatic axilla. Material and methods: This was a prospective observational trial involving two Italian Breast Units: Policlinico di Sant’Orsola and San Raffaele hospital. Objective was to evaluate that the omission of ALND in patients with cT1-2 cN0 BC undergoing breast conserving surgery (BCS) and histological finding of metastases in 1 or 2 SLN is not associated with a worse prognostic outcome. Primary endpoint was overall survival (OS). Secondary endpoints were disease free survival (DFS) and locoregional recurrence. All BC patients treated between the 1st of November 2020 and 31st of July 2023 with cT1-2 cN0 BC, preoperative negative axillary ultrasound and 1 or 2 metastatic SLN treated with sentinel node biopsy (SLNB) alone entered the study. Results: 795 cT1-2 cN0 BC patients underwent BCS and SLNB. Ninety patients were included. Median age was 60 (52-68) years. Seventy-five patients (83%) had T1 tumor and 15 (17%) T2. Median tumor size was 16 mm (11-19). The median SLN removed was 2 (1-3). Eighty-one patients had 1 positive SLN (90%), while 9 had 2 SLN metastasis (10%). 39 (43%) micrometastases were identified and 51 macrometastasis (57%). All patients underwent radiotherapy. Seventeen (19%) performed adjuvant chemotherapy. Two received immunotherapy with trastuzumab and pertuzumab. Endocrine therapy was given to 84 (93%). At a median follow-up of 19 months (IQR 13-23) OS and DFS were 100%. No loco-regional recurrence was seen. Conclusion: The preliminary results of our study confirm that omitting ALND in patients meeting Z011 criteria is oncologically safe and should be the standard of care.