From Prophylactic Screening to Definitive Treatment: A Case Report of Breast Cancer in a Young Woman.

This article presents the case of a 39-year-old woman with a positive family history of breast cancer (her family member had left breast cancer, cT4N2M0, non-luminal human epidermal growth factor receptor 2 (HER2)-positive). During routine prophylactic ultrasonographic examination, a breast mass was detected, which, on further diagnostics, turned out to be an invasive ductal carcinoma of the left breast. The stage of the disease was determined as pT1cN1mic(sn), Nottingham Histologic Grade 3 (NHG 3). The patient was subjected to surgical treatment, which involved left mastectomy with simultaneous removal of the axillary sentinel lymph node. Subsequently, adjuvant chemotherapy was administered, including a "dose-dense" regimen with the use of doxorubicin and cyclophosphamide, followed by treatment with paclitaxel. During chemotherapy, complications related to the implantation of a vascular port occurred, which resulted in its removal before the completion of treatment. After the completion of chemotherapy, breast reconstruction was performed. During the entire treatment process, extended genetic diagnostics were performed, which did not demonstrate the presence of pathogenic gene mutations. The treatment was completed, and the patient remains under continuous care of the oncology outpatient clinic.