Endocrine therapy in postmenopausal patients: a graded approach

At the St. Gallen Conference 2017, a small majority of the panellists (55%) took the view that for most postmenopausal patients an aromatase inhibitor (AI) should be considered at some point in the course of treatment. This year, almost all panellists (96%) were of this opinion. Parameters that favour the inclusion of an AI at some point in the course of treatment of postmenopausal patients are grade 3 or high Ki67 (83% of the panellists voted “yes”) and Her2 positivity (68% of the panellists voted “yes”). Upfront therapy with an AI should be considered in all postmenopausal patients of high risk by stage or tumour volume (94% of the panellists voted “yes”) but not in all postmenopausal patients (59%% of the panellists voted against upfront AI in all postmenopausal patients). In postmenopausal patients, the historical duration of endocrine therapy is 5 years. Recently, Gray at al. presented a meta-analysis of studies that explored the benefit of extended endocrine therapy [1]. At the St. Gallen Conference 2019 the panellists were asked in which particular situations the endocrine therapy should be extended beyond 5 years of duration. For patients with stage 1 breast cancer who had 5 years of tamoxifen, a majority of the panellists (72%) would not recommend extending the endocrine therapy beyond 5 years. One of the panellists remarked that this result contradicts the earlier statement of 96% of the panel that treatment with an AI should be considered for all postmenopausal patients at some point in the course of treatment. A majority of the panellists (78%) also would not recommend extension of endocrine therapy for patients with stage 1 breast cancer who had 5 years of AI treatment. For a postmenopausal patient who has stage 2 node-negative breast cancer and who had 5 years of tamoxifen, 68% of the panellists would recommend extended endocrine therapy beyond 5 years. However, for a postmenopausal patient who has stage 2 node-negative breast cancer and who had 5 years of AI treatment, 35% of the panellists would recommend extended endocrine therapy while 59% of the panellists would not.

For postmenopausal patients with stage 2 node-positive breast cancer, a vast majority of the panel was in favour of extended endocrine therapy beyond 5 years: 98% of the panellists recommended extended endocrine therapy after 5 years of tamoxifen; 81% of the panellists recommended extended endocrine therapy after 5 years of AI treatment. Asked their opinion on the optimal duration of the extended endocrine therapy, 38% of the panellists voted for a total duration of the endocrine therapy of 7-8 years, while 59% of the panellists voted for 10 years. A majority of the panellists (60%) took the view that for postmenopausal patients at very high risk (10 or more positive nodes), extended endocrine therapy should not routinely be recommended but should be considered on a case by case basis.

1.  Gray R, et al. SABCS 2018, abstract GS3-03.

Posted on 21 May 201915 March 2021