Combined anti-HER2 and hormonal treatment in a patient with HR⁺HER2⁺ clear-cell uterine carcinoma: A case report

Clear-cell carcinoma (CCC) of the uterus is an aggressive disease. Current international guidelines on the treatment of uterine carcinomas predominantly cover cancer with endometrioid histology, and clinicians tend to use the same approach for patients with non-endometrioid histology due to the absence of separate guidelines for these rare tumor types. At present, molecular analysis enables the assessment of novel and non-standard treatment options based on the individual characteristics of a tumor. The present report presents a clinical case of successful treatment of a patient with clear cell uterine carcinoma with HER2 and ER expression. Non-toxic targeted treatment was used based on immunohistochemistry (IHC) data. The patient received anti-HER2 and hormonal treatment and demonstrated an excellent response. The follow-up period was 47 months and the patient remained stable during treatment without significant toxicity. Therefore, this approach demonstrated the potential for selecting highly-specific therapy for rare tumors, which lack distinct recommendations for their treatment.