Pregnancies during and after trastuzumab and/or lapatinib in patients with human epidermal growth factor receptor 2–positive early breast cancer: analysis from the NeoALTTO (BIG 1-06) and ALTTO (BIG 2-06) trials
A partir des données de deux essais de phase III incluant des patientes atteintes d'un cancer du sein de stade précoce HER2+, cette étude analyse l'effet des traitements anticancéreux (lapatinib, trastuzumab) sur la survenue d'une grossesse, ses complications et son issue, que ces traitements aient été dispensés avant la grossesse ou en début de grossesse (non connue)
Background : Limited data exist on the safety of using anti–human epidermal growth factor receptor 2 (HER2) targeted agents during pregnancy. To date, only retrospective studies have assessed the prognosis of patients with a pregnancy after prior early breast cancer, with no data in HER2-positive patients. Methods The Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimization (NeoALTTO) trial and the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization (ALTTO) trial were randomized phase 3 trials for patients with HER2-positive early breast cancer. In both trials, pregnancy information was prospectively collected. Pregnancy outcomes were compared between patients unintentionally exposed to trastuzumab and/or lapatinib during gestation (the exposed group) and those who became pregnant after trastuzumab and/or lapatinib completion (the unexposed group). In the ALTTO trial, disease-free survival (DFS) was compared between pregnant patients and those aged 40 years or younger without a subsequent pregnancy via an extended Cox model with time-varying covariates to account for a guarantee-time bias. Results Ninety-two patients (12 in the exposed group and 80 in the unexposed group) had a pregnancy: 7 in the NeoALTTO trial and 85 in the ALTTO trial. Seven patients (58.3%) in the exposed group and 10 patients (12.5%) in the unexposed group opted for an induced abortion; in the unexposed group, 10 patients (12.5%) had a spontaneous abortion. No pregnancy/delivery complications were reported for the remaining cases, who successfully completed their pregnancy, with the exception of 1 fetus with trisomy 21 (Down syndrome). No significant difference in DFS (adjusted hazard ratio, 1.12; 95% confidence interval, 0.52-2.42) was observed between young patients with a pregnancy (n = 85) and young patients without a pregnancy (n = 1307). Conclusions For patients with HER2-positive early breast cancer, having a pregnancy after treatment completion appears to be safe without compromising fetal outcome or maternal prognosis.