Is hormonal therapy effective in advanced endometrial cancer? A systematic review and meta-analysis

Hormonal therapy (HT) is used commonly in the treatment of advanced endometrial cancer (EC). However, a 2010 Cochrane Review did not show a survival benefit for HT. Here, we quantify its effects and explore the influence of clinico-pathologic factors and hormone receptor (HR) status on overall response rates (ORR).

A systematic search of electronic databases identified publications of HT in advanced EC. Data from individual studies reporting ORR, median progression-free (PFS) or overall survival (OS) were weighted by individual study sample size and pooled in a meta-analysis. Outcomes of estrogen (ER) and progesterone receptor (PgR) subgroups were collected. Studies of first- and second-line HT were analyzed independently. Mixed studies were included if subgroup data based on previous HT exposure were provided. Meta-regression was performed to evaluate the influence of clinico-pathologic factors on outcomes.

Thirty-nine studies were included, with seven providing subgroup data based on HR status. First-line HT was associated with a mean ORR of 21.6% and clinical benefit rate (CBR) of 36.7%. Median PFS and OS were 2.8 and 10.2months respectively. ORR was 20.4% in clinical trials and 25.3% in observational studies. Magnitude of ORR was lower in older age, adenosquamous histology and high grade. ORR was higher in ER+ (26.5%) and PgR+ (35.5%) disease, and lower in ER- (9.2%) or PgR- (12.1%) tumors. Second-line ORR was 18.5%. CBR was 35.8%, but was significantly associated with timing of stable disease assessments in first- and second-line. Meta-regression performed in mixed and second-line studies showed an association between previous HT and greater ORR (β 0.561; p=0.024), suggesting potential confounding by indication (re-treatment of good responders to first-line HT).

HT is associated with modest ORR in advanced EC, and is greatest in HR+ tumors. Response rates in second-line are likely dependent on response to previous HT.