An observational study in Breast Cancer and Early Breast Cancer, sponsored by Institute of Oncology Ljubljana. Completed at 1 site in Slovenia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-19.
Sponsored by Institute of Oncology Ljubljana · Observational
This study aims to investigate the correlation between immune-related factors in the tumor stroma and pathological complete response (pCR) in patients with early breast cancer treated with neoadjuvant chemotherapy. In addition, the study evaluates the association between immune-related tumor stroma factors and the presence of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) in peripheral blood. The study includes serial blood sampling before and after treatment and during follow-up to assess the prognostic value of these biomarkers for disease progression and recurrence.
Neoadjuvant chemotherapy is widely used in patients with early breast cancer to reduce tumor size and improve surgical outcomes. Achieving a pathological complete response (pCR) is associated with improved prognosis; however, reliable predictive biomarkers are still limited. Recent evidence suggests that immune cells in the tumor microenvironment may influence treatment response.
This study evaluates immune-related tumor stroma factors (including tumor-infiltrating lymphocytes and immune marker profiles) in tumor tissue obtained prior to treatment. In parallel, circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) are assessed from peripheral blood samples collected before neoadjuvant chemotherapy, after completion of treatment, and during follow-up.
The primary objective is to determine whether immune-related tumor stroma factors correlate with pCR after neoadjuvant chemotherapy. Secondary objectives include evaluating the association of immune-related factors with the presence of CTCs and ctDNA and assessing their prognostic value for disease progression and recurrence.
12,544 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.
This study's enrollment of 171 is close to the median of 184 across 2,642 observational studies indexed under Breast Neoplasms.
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The study population includes adult patients with histologically confirmed early breast cancer treated at the Institute of Oncology Ljubljana who are candidates for standard-of-care neoadjuvant chemotherapy. Participants are enrolled prospectively and followed through surgery and subsequent follow-up to assess pathological complete response (pCR) and associations with tumor-infiltrating lymphocytes and circulating biomarkers.
Exclusion Criteria:
Patients with early breast cancer receiving standard-of-care neoadjuvant chemotherapy according to institutional and international guidelines. Treatment is determined by the treating physician and is not assigned by the study protocol.
Other: Standard-of-Care Neoadjuvant Chemotherapy
Standard neoadjuvant chemotherapy administered as part of routine clinical care. The regimen is determined by the treating physician and is not assigned by the study protocol.
Pathological Complete Response (pCR)
Pathological complete response is defined as the absence of invasive carcinoma in the breast and axillary lymph nodes after neoadjuvant chemotherapy (ypT0/Tis ypN0).
Time frame: At surgery following completion of neoadjuvant chemotherapy
Plan to share: No
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This study is completed, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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Institute of Oncology Ljubljana