Dr. Konstantinopoulos on Immunotherapy in Ovarian Cancer

Panagiotis A. Konstantinopoulos, MD, PhD, director of Translational Research, Gynecologic Oncology, Dana-Farber Cancer Institute, associate professor of medicine, Harvard Medical School, discusses the role of immunotherapy in the treatment of patients with ovarian cancer.

Unlike cervical and uterine cancers where there are FDA-approved indications for pembrolizumab (Keytruda), there are not yet any approved uses for immunotherapy in ovarian cancer. With that being said, it is important to note that pembrolizumab is still a reasonable treatment strategy for the rare subset of patients whose tumors are microsatellite instability—high (MSI–H).

The incidence of MSI—H is very low in high-grade serous ovarian cancer, Konstantinopoulos explains, appearing in just 1% to 2% of cases. MSI–H is also observed in the low-grade endometrioid subtype of ovarian cancer, as well as in clear cell ovarian cancer, which is a highly aggressive and unique subtype of the disease.

In a study conducted at Dana-Farber Cancer Institute, investigators found that in 30 patients with clear cell disease, 3 of them had MSI—H tumors, which was also associated with high PD-L1 expression. There is rationale to test every patient with clear cell ovarian cancer for MSI–H using immunohistochemistry, Konstantinopoulos notes. Although these tumors are very rare, they can be matched with effective therapies.