Correlation Between Tumor-infiltrating Lymphocytes and Response to Systemic Therapy in Breast Cancer

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.

Inclusion criteria

• Female patients aged 18 years or older.
• Histologically confirmed early breast cancer.
• Candidates for standard neoadjuvant chemotherapy.
• Ability to provide informed consent.

Exclusion criteria

• Luminal A subtype of breast cancer.
• Prior systemic therapy for breast cancer.
• Serious comorbid conditions that would preclude study participation.