One discovery leads to another treatment
This discovery led to the approval of trastuzumab to be used in addition to chemotherapy for advanced or recurrent disease.2 The most significant effects appear to be among those who have not received prior therapies, with a doubling of progression-free survival among these patients, and a more modest response among patients treated for recurrent, mostly pretreated disease.
Work currently is underway to explore an array of antibody or small-molecule blockades of HER2 in addition to vaccines against the protein or treatment with conjugate compounds in which an antibody to HER2 is paired with a cytotoxic drug able to be internalized into HER2-expressing cells.7 This represents a form of personalized medicine referred to as biomarker-driven targeted therapy, in which therapies are prescribed based on the expression of specific molecular markers (such as HER2 expression) typically in combination with other clinical markers such as surgical staging results, race, age, etc. These approaches can be very effective strategies in rare tumor subtypes with distinct molecular and clinical behaviors.
As previously mentioned, the targeting of HER2 overexpression with trastuzumab has been shown to be highly effective in the treatment of HER2-positive breast cancers where even patients with early-stage disease receive a multimodal therapy approach including antibody, chemotherapy, surgical, and often radiation treatments.6 We are moving towards a similar multimodal comprehensive treatment strategy for UPSC. If it is as successful as it is in breast cancer, it will be long overdue, and desperately necessary given the poor prognosis of this disease for all stages because of the inadequacies of current treatments strategies.
Routine testing of UPSC for HER2 expression is now a part of routine molecular substaging of uterine cancers in the same way we have embraced testing for microsatellite instability and hormone-receptor status. While a diagnosis of HER2 overexpression in UPSC portends a poor prognosis, patients can be reassured that treatment strategies exist that can target this malignant mechanism in advanced disease and more are under further development for early-stage disease.
Dr. Rossi is assistant professor in the division of gynecologic oncology at the University of North Carolina at Chapel Hill. She has no relevant financial disclosures. Email her at.