Cancer Plus

Glutamate pyruvate transaminase 2 (GPT2) is one of the GPTs and is widely used as a biomarker of hepatocellular injury, along with GPT1. GPT2, a glutamine-metabolizing transaminase found in mitochondria, catalyzes the reversible process between glutamate, pyruvate, α-ketoglutarate, and alanine. Compared to GPT1, the intracellular abundance of GPT2 is higher, suggesting that its enzymatic activity has a considerable role in glucose metabolism, amino acid metabolism, and lipid metabolism. In recent years, it has been discovered that deletion or mutation of GPT2 causes malignant transformation of tumors and that its expression level is closely correlated with tumor development. It is for this reason that the level of GPT2 can be used to reflect the metabolism level of the tumor cells in the body and can indicate metastasis based on its changes. The metabolism level of GPT2 in tumor cells is expected to be a marker in the tumor diagnostic process and subsequently contribute to early detection, thus improving tumor diagnosis and patient prognosis. This paper presents an overview of the current state of GPT2 research in the progression of tumors.

Ewing’s sarcoma (EWS) typically involves the bony structures in adolescents and young adults. Extraskeletal sarcoma is a rare, aggressive, and malignant soft-tissue tumor with high recurrence rate. EWS of the breast is a rare entity with <1% cases reported in literature. A 55-year-old lady who complained of the gradual onset painless breast lump lasting for 1 year was referred to our institute in August 2021. Diagnostic ultrasound of bilateral breast identified a cystic lesion measuring 1.8 × 1.5 cm in lower inner quadrant of right breast. Diagnostic excisional biopsy of the right breast lump, which was conducted outside of the institute, showed malignant small round cell tumor. Post-excisional biopsy whole body 18-fluoro-deoxy-glucose positron emission tomography showed no residual uptake with no evidence of metastatic disease elsewhere. Immunohistochemistry work revealed positive expression of NKX2.2 and MIC2, which is consistent with the histopathological feature of EWS. Fluorescent in situ hybridization showed EWSR1 rearrangement, which is consistent with the diagnosis of EWS. The patient underwent a wide local excision of the right breast, followed by adjuvant chemotherapy consisting of 18 weekly vincristine/adriamycin D/cyclophosphamide regimen (vincristine, total dose of 2 mg; adriamycin D 100 mg; and cyclophosphamide 1.6 g). The patient was disease free after follow-up of 1 year. The rarity of primary breast EWS poses a diagnostic dilemma and hence the treatment. Local control with systemic therapy is the cornerstone of the treatment, in which breast conservation surgery is equivalent to mastectomy in patient with a good/average breast volume.