Case report of stage IIIC low-grade serous ovarian cancer in a 13-year-old female treated with novel therapy.

Low-grade serous ovarian carcinoma (LGSOC) is a rare malignancy in pediatric populations, with most ovarian tumors in adolescents typically being of germ cell origin. LGSOC is a distinct subtype of serous ovarian carcinoma characterized by slow progression, frequent estrogen receptor (ER) positivity, and resistance to traditional chemotherapy. Despite its indolent nature, most patients ultimately experience disease recurrence, highlighting the need for alternative treatment approaches. This report presents the case of a 13-year-old female diagnosed with advanced-stage LGSOC following menarche. She initially presented with unintentional weight loss, constipation, and early satiety, and imaging revealed extensive pelvic disease. Given the tumor's limited sensitivity to chemotherapy, she was treated with neoadjuvant endocrine therapy (ET) using fulvestrant, palbociclib, and leuprolide. This regimen led to substantial tumor regression and normalization of CA-125 levels. Following 15 cycles, she underwent interval debulking surgery, achieving optimal cytoreduction while preserving the uterus. She continues adjuvant therapy with no signs of disease progression. Given the long-term effects of hormonal suppression in adolescents, careful monitoring is essential. Recent studies suggest that targeted therapies, including MEK and CDK4/6 inhibitors, may improve outcomes in LGSOC. Research has shown promising response rates and reduced toxicity compared to traditional chemotherapy. This case supports the potential role of endocrine-based targeted therapy in managing pediatric LGSOC, offering a viable alternative for patients with limited treatment options. Further research is needed to optimize treatment strategies and improve survival outcomes in this rare population.