Her2-positive breast cancer in a young patient with Li-Fraumeni syndrome: A comprehensive case study.

ABSTRACT

INTRODUCTION AND IMPORTANCE Li-Fraumeni syndrome (LFS) is a rare hereditary disorder caused by mutations in the TP53 gene, leading to a significantly increased risk of developing various cancers at a young age, including breast cancer. CLINICAL PRESENTATION This case report details the clinical journey of a 21-year-old female diagnosed with Grade 3 invasive ductal carcinoma, which was estrogen receptor low positive and progesterone receptor negative but positive for Her2 (3+) with a high Ki67 proliferation index. CLINICAL DISCUSSION: Genetic testing confirmed a TP53 mutation, establishing the diagnosis of LFS. The patient underwent neoadjuvant chemotherapy with TCHP (docetaxel, carboplatin, trastuzumab, pertuzumab), resulting in a complete clinical response. This was followed by bilateral skin-sparing and nipple-sparing mastectomy with sentinel lymph node biopsy and immediate reconstruction. Postoperative pathology confirmed a complete response to neoadjuvant therapy. The patient's treatment plan includes 12 cycles of trastuzumab and pertuzumab, with regular echocardiograms to monitor cardiac function and fertility preservation strategies involving monthly Lupron injections. Given the association of LFS with a high risk of multiple primary cancers, a rigorous surveillance strategy is essential. The psychological impact of a cancer diagnosis and the burden of living with a hereditary cancer syndrome were significant, necessitating comprehensive psychosocial support. CONCLUSION: Managing Li-Fraumeni syndrome (LFS) and its associated cancers, particularly in young patients, necessitates a comprehensive and multidisciplinary approach. Early genetic testing for TP53 mutations is crucial in identifying LFS, enabling personalized treatment plans and proactive surveillance strategies.