Pharmacogenomics-Guided Adjuvant Chemotherapy in UESL
Background  Undifferentiated embryonal sarcoma of the liver (UESL) is a rare, aggressive mesenchymal tumor in children, with historically poor prognosis. No standardized adjuvant chemotherapy exists. Pharmacogenomic testing can individualize treatment by predicting drug efficacy and toxicity based on genetic polymorphisms, but its application in UESL has not been reported.  Case presentation  We report a 14-year-old male presenting with right upper quadrant pain and fever. Imaging revealed a large mixed cystic-solid mass in the right hepatic lobe. He underwent R0 right hemihepatectomy. Histopathology and immunohistochemistry confirmed UESL with a Ki-67 index of 40%. Postoperative multigene pharmacogenomic testing (84-gene panel) identified key polymorphisms in TP53, ABCB1, and ERCC1, which guided selection of an individualized adjuvant chemotherapy regimen (VDC/IE: vincristine, doxorubicin, cyclophosphamide/ifosfamide, etoposide). The patient completed six cycles without dose reduction or delay, experiencing only grade 1–2 myelosuppression. At 36 months postoperatively, imaging showed no recurrence or metastasis, and the patient had returned to all normal activities.  Conclusions  This is the first report of systematic multigene pharmacogenomic testing to guide adjuvant chemotherapy in UESL. The patient achieved 36-month disease-free survival with favorable tolerability, a result comparable to or better than historical outcomes with empirical therapy. This case supports the integration of pharmacogenomic testing into individualized treatment strategies for rare sarcomas.
Background  Undifferentiated embryonal sarcoma of the liver (UESL) is a rare, aggressive mesenchymal tumor in children, with historically poor prognosis. No standardized adjuvant chemotherapy exists. Pharmacogenomic testing can individualize treatment by predicting drug efficacy and toxicity based on genetic polymorphisms, but its application in UESL has not been reported.  Case presentation  We report a 14-year-old male presenting with right upper quadrant pain and fever. Imaging revealed a large mixed cystic-solid mass in the right hepatic lobe. He underwent R0 right hemihepatectomy. Histopathology and immunohistochemistry confirmed UESL with a Ki-67 index of 40%. Postoperative multigene pharmacogenomic testing (84-gene panel) identified key polymorphisms in TP53, ABCB1, and ERCC1, which guided selection of an individualized adjuvant chemotherapy regimen (VDC/IE: vincristine, doxorubicin, cyclophosphamide/ifosfamide, etoposide). The patient completed six cycles without dose reduction or delay, experiencing only grade 1–2 myelosuppression. At 36 months postoperatively, imaging showed no recurrence or metastasis, and the patient had returned to all normal activities.  Conclusions  This is the first report of systematic multigene pharmacogenomic testing to guide adjuvant chemotherapy in UESL. The patient achieved 36-month disease-free survival with favorable tolerability, a result comparable to or better than historical outcomes with empirical therapy. This case supports the integration of pharmacogenomic testing into individualized treatment strategies for rare sarcomas.