Neoadjuvant letrozole in postmenopausal estrogen and/or progesterone receptor positive breast cancer: A phase IIb/III trial to investigate optimal duration of preoperative endocrine therapy

Abstract

Background: In recent years, preoperative volume reduction of locally advanced breast cancers, resulting in higher rates of breast-conserving surgery (BCS), has become increasingly important also in postmenopausal women. Clinical interest has come to center on the third-generation nonsteroidal aromatase inhibitors (AIs), including letrozole, for such neoadjuvant endocrine treatment. This usually lasts 3-4 months and has been extended to up to 12 months, but optimal treatment duration has not been fully established.

Early metabolic response to neoadjuvant letrozole, measured by FDG PET/CT, is correlated with a decrease in the Ki67 labeling index in patients with hormone receptor-positive primary breast cancer: a pilot study

“…However, these studies did not determine the optimum duration of treatment. Therefore, Krainick-Strobel et al [25] investigated the optimal duration of neoadjuvant letrozole therapy in postmenopausal patients with HR-positive breast cancer. Their data suggested that prolonged treatment for up to 8 months could result in greater tumor shrinkage compared with treatment for 4 months.…”

Neoadjuvant endocrine therapy of breast cancer: which patients would benefit and what are the advantages?

“…The clinical tumor responses of neoadjuvant AIs were analyzed in single-arm trials [11][12][13][14][15][16][17][18][19], which are chronologically listed in Table 2. Three to 12 months of neoadjuvant use of AIs revealed that partial response or complete response rates evaluated by palpation were 41-80%, and progressive disease rates were 0-7%.…”

Les traitements néoadjuvants (hors cancer du sein inflammatoire)

“…une phase IIb/III • s'est intéressée à la question de la durée optimale de l'HNA [80], mais ne permet pas d'y répondre. Il s'agit d'une étude conduite, avec le létro-zole, chez 33 femmes seulement, ayant une tumeur RH+, d'emblée non accessible à une CS.…”