Vivianne C.G. Tjan-Heijnen, MD, PhD
In the phase III DATA trial reported in the Journal of the National Cancer Institute by Vivianne C.G. Tjan-Heijnen, MD, PhD, of the Maastricht University Medical Centre, the Netherlands, and colleagues, 12% of women with breast cancer who had chemotherapy-induced ovarian function failure experienced ovarian function recovery during 30 months of aromatase inhibitor therapy with anastrozole. The trial compared 3 vs 6 years of adjuvant anastrozole in postmenopausal women with hormone receptor–positive disease who had received 2 or 3 years of tamoxifen.
The study involved 329 breast cancer patients with chemotherapy-induced ovarian function failure in the study population. Estradiol levels during aromatase inhibitor treatment were analyzed in a nested case-control analysis comparing 102 control subjects without ovarian function recovery with ovarian function recovery patients, with the estradiol value at ovarian function recovery diagnosis being excluded.
The 329 patients with ovarian function failure had a median age of 50.0 years (range = 45–57 years). Ovarian function recovery occurred in 39 patients overall, yielding a 30-month recovery rate
of 12.4%. Of them, 11 (28.2%) were aged ≥ 50 years at aromatase inhibitor initiation; the function recovery rate was 5.1% in these patients vs 25.2% in those aged < 50 years.
Estradiol levels decreased by 37.8% over 30 months of aromatase inhibitor treatment in both groups in the case-control analysis. However, levels in the ovarian function recovery group remained significantly higher than in the non–ovarian function recovery group (difference = 20.6%, P = .03).
The investigators concluded: “The risk of [ovarian function recovery] during [aromatase inhibitor] treatment in breast cancer patients with chemotherapy-induced ovarian function failure is relevant, even beyond 45 years [of age]. Furthermore, women experiencing [ovarian function recovery] had statistically significant higher estradiol levels during [aromatase inhibitor] treatment (before [ovarian function recovery]) than those without, with potential consequences regarding efficacy.” ■