Follow-up of a Li-Fraumeni syndrome case

Abstract

Introduction: Li-Fraumeni syndrome (LFS) is responsible for about 1% of hereditary breast cancers (BC). We present a
case report of a young woman with synchronous osteosarcoma and BC. Case Report: NOB, 23 years old. Mother died
with BC at 36 years old and sister died due to neuroblastoma at 2 years old. She was referred in 2021 for a nodule in her
left breast and the ultrasound results showed an irregular nodule of 1.5×1.2×1.3 cm BI-RADS®5 and anatomopathological invasive carcinoma of non-special histological type (NST), estrogen receptor 80%, progesterone receptor 100%, Her2
negative, and Ki67 60% cT1N0. It was associated with a lesion in the alveolar mucosa with bleeding and deformity of the
oral cavity with anatomopathological high histological osteosarcoma-T1N0. Surgical treatment was performed: maxillectomy of meso and bilateral infrastructure+tracheostomy+reconstruction with microsurgical flap of the fibula and, then,
left adenomastectomy+sentinel lymph node biopsy+prosthesis reconstruction. Surgical anatomopathological results in
central/medullary high-grade conventional osteosarcoma chondroblasts 7.3×6.1×3.9 cm, free surgical margins and four
cervical lymph nodes free of neoplastic involvement, and invasive breast carcinoma NST with medullary characteristics
1.8×1.3 cm, free margins, and absence of metastasis in two sentinel lymph nodes –pT1pN0. Genetic test resulted in pathogenic mutation TP53 gene, position chr17:7.674.257, consequence p.Tyr236HisENST00000269305. Adjuvant chemotherapy
was docetaxel+cyclophosphamide. Two years after treatment, she is taking tamoxifen, scheduled for contralateral adenomastectomy, and maintains high-risk follow-up. There is no signal of any cancer disease. Discussion: LFS is an autosomal dominant inheritance of high penetrance. The diagnosis is based on the identification of a pathogenic variant in the
TP53 gene. It is related to several tumors diagnosed at an early age. BC is the most common cancer and affects 27–31%
of patients. Osteosarcoma corresponds to 3%–16% of cases, usually occurring before the age of 30 years. The prognosis of
patients does not differ from those with sporadic cancer. They must be monitored by a multidisciplinary team, screening
with annual whole body/breast MRI and mammography, and colonoscopy every 5 years. Genetic counseling is essential.