STIC CTC trial data published this November 2023 in the Journal of Clinical Oncology (JCO) demonstrate that CTC-guided treatment decision confers superior survival benefits in a subgroup of patients with hormone receptor (HR) positive)/human epidermal growth factor receptor (HER) 2 negative metastatic breast cancer (MBC), the most common subtype of newly diagnosed breast cancer. Clinical outcomes from this large phase III patient cohort were reported after almost 10 years of investigational work. The STIC CTC trial was sponsored by Institut Curie and funded by the French National Cancer Institute.

BOLOGNA, Italy and HUNTINGDON VALLEY, Pa., Jan. 16, 2024 /PRNewswire/ — Menarini Silicon Biosystems, a pioneer of liquid biopsy and single-cell technologies, announced the recent publication of the STIC CTC trial data demonstrating the clinical utility of CTC count as an independent prognostic factor in advanced breast cancer.

More specifically, the STIC CTC trial demonstrates that the use of CTC count as a tool for choosing between endocrine therapy (ET) and chemotherapy (CT) is non-inferior to the investigator’s choice in terms of short and long-term clinical outcomes. While approximately 60% of the study participants had a concordant indication between the clinical risk-guided arm and the CTC-guided treatment arm, in the subgroup of patients with a discordant estimate, the use of frontline CT in the CTC-guided treatment arm instead of ET yielded a clinically and statistically significant gain of 16.4 months in median overall survival (OS). Conversely, in the subgroup of patients considered at high clinical risk but with a favorable prognosis according to CTC count, de-escalation to ET allowed to limit the exposure to the side effects and toxicities of chemotherapy without any significant effect on overall survival.

FC Bidard, MD, PhD, Professor of Medical Oncology at the Institut Curie hospitals and who designed the trial mentioned, “the STIC trial is a first-of-its-kind randomized Phase III trial establishing with a high level-of-evidence that CTC-driven choice offers a long-term OS benefit in patients with discrepant estimates between their CTC count and the clinician’s choice.”

In addition, the Principal Investigator of the STIC CTC trial, Jean-Yves Pierga, MD, PhD, Professor of Medical Oncology, at the Institut Curie hospitals, “the clinical relevance of CTCs as highlighted in the STIC CTC trial, makes it possible to standardize the choice of ET or CT and meaningfully optimize patient care with a 47% reduction in the risk of death in patients with poor prognosis”. 

In the metastatic setting, expectations regarding confirmatory prospective clinical trials to incorporate CTC data into clinical practice have been high for almost two decades now. According to Massimo Cristofanilli, MD, FACP, Professor of Medicine & Director of Breast Medical Oncology in the Division of Hematology and Medical Oncology at Weill Cornell Medicine, “The STIC CTC trial is the first robust clinical trial that has met those expectations by demonstrating the usefulness of CTC count as both a prognostic and predictive biomarker. Thus, there is no rational reason to deny women with MBC the right to benefit from this information that can help their physicians prescribe therapies that can more optimally meet their specific needs”.

Liquid biopsies aim to provide critical information in real time to enhance the precision oncology approach. Fabio Piazzalunga, President of Menarini Silicon Biosystems, adds that “the confirmed ability of our minimally invasive CELLSEARCH CTC test, to help identify low-risk patients and avoid unnecessary treatments, is currently at the heart of the reimbursement requests, now underway in different countries, for use of this biomarker to tailor treatment strategies in an advanced disease setting”. These new activities fully support the company’s vision to become a leader in minimally invasive cell-based applications for easier, faster, and more precise diagnostic and therapeutic approaches.


CELLSEARCH CTC Test is the first and only clinically validated blood test cleared by the U.S. Food & Drug Administration (FDA) for detecting and counting CTCs to aid physicians in managing patients with metastatic breast, prostate, and colorectal cancers when used in conjunction with other clinical methods of monitoring. The CELLSEARCH System is the most extensively studied CTC technology, with research published in more than 800 peer-reviewed publications.

CELLSEARCH CTC Test is not cleared or approved for independently guiding treatment decisions. For more information on the full intended use and limitations of the CELLSEARCH system, please refer to the Instructions for Use at

In Europe the CELLSEARCH CTC kit is available for In Vitro Diagnostic (IVD) Use.

In the US the CELLSEARCH CTC Test is available in MSB’s CLIA/CAP/ ISO 15189 accredited laboratory in Huntingdon Valley, Pa.

About Menarini Silicon Biosystems (MSB)

MSB offers unique rare cell technologies and solutions that provide clinical researchers with access to unparalleled resolution in the study of cells and their molecular characterization.

Menarini Silicon Biosystems, based in Bologna, Italy, and Huntingdon Valley, Pa., U.S., is a wholly owned subsidiary of the Menarini Group, a multinational pharmaceutical, biotechnology and diagnostics company headquartered in Florence, Italy, with more than 17,000 employees in 140 countries.

Media contact: Linda PAVY,