OPTImaL:Optimisation of Treatment for Patients With Low Stage Triple-negative Breast Cancer With High Stromal Tumor-infiltrating Lymphocytes

This study is testing whether close monitoring alone — without additional chemotherapy — is enough for people with a type of early-stage, highly immune-active triple-negative breast cancer (TNBC). TNBC is a breast cancer type that lacks three common receptors used by other treatments. In these early-stage tumors with high immune cell infiltration, some patients may not need additional treatment after surgery, and this trial aims to find out if that is safe. **You may be eligible if...** - You have stage I (small, early-stage) triple-negative breast cancer (TNBC) - Your tumor is 2 cm or smaller and has not spread to lymph nodes - Your tumor has a high proportion of immune cells (TILs ≥50% if age ≥40, or ≥75% if age <40) - You have already had curative breast surgery - You have had imaging confirming no cancer spread **You may NOT be eligible if...** - You have had prior breast cancer (invasive or non-invasive) - Your cancer is in multiple spots or in both breasts - You received chemotherapy before surgery (neoadjuvant therapy) - You have another active cancer within the past 5 years - You have uncontrolled serious illness Talk to your doctor to see if this trial is right for you.