Hormonal therapy for recurrent low-grade serous carcinoma of the ovary or peritoneum

To determine whether hormonal therapies have efficacy in patients with recurrent low-grade serous carcinoma of the ovary or peritoneum.

We searched departmental databases for patients with histologically-confirmed, evaluable, recurrent low-grade serous ovarian or peritoneal carcinoma who received hormonal therapy at our institution between 1989 and 2009. We retrospectively reviewed patients' medical records for demographic, disease, hormonal therapy, and estrogen receptor and progesterone receptor expression data. We used the Response Evaluation Criteria in Solid Tumors version 1.1 to determine patients' responses to hormonal therapy. Because patients could have received more than one evaluable hormonal therapy regimen, we chose to define the outcome metric as "patient-regimens." Median time to disease progression (TTP) and overall survival (OS) were also calculated. Regression analysis was also performed.

We identified 64 patients with recurrent low-grade serous carcinoma of the ovary or peritoneum. Patients' median TTP and median OS were 7.4 and 78.2 months, respectively. Patients received 89 separate hormonal patient-regimens, which produced an overall response rate of 9% (6 complete responses and 2 partial responses). Sixty-one percent of the patient-regimens resulted in a progression-free survival duration of at least 6 months. Patient-regimens involving ER+/PR+ disease produced a longer median TTP (8.9 months) than patient-regimens involving ER+/PR- disease did (6.2 months; p=0.053). This difference approached but did not reach statistical significance.

Hormonal therapies have moderate anti-tumor activity in patients with recurrent low-grade serous carcinoma of the ovary or peritoneum. Further study to determine whether ER/PR expression status is a predictive biomarker for this rare cancer subtype is warranted.