Tamoxifen treatment for male breast cancer and risk of thromboembolism: prospective cohort analysis

Holm Eggemann,Mattea Reinisch,Florin-Andrei Taran,Atanas Ignatov,Sibylle Loibl,Serban-Dan Costa,Anna-Lena Bernreiter

doi:10.1038/s41416-018-0369-2

Abstract

PurposeThromboembolism is a common adverse event in women treated with tamoxifen (TAM) for breast cancer. The risk in male breast cancer patients is poorly investigated. We aimed to examine the risk of thrombotic events after TAM in male breast cancer patients.Patients and methodsIn this prospective cohort study, 448 patients treated between May 2009 and July 2017 for male breast cancer (BC) were assessed for eligibility. Patients with follow-up shorter than 6 months were excluded. The cumulative risk of thromboembolism was evaluated.ResultsThe median follow-up was 47 months (range 6–101 months) with a median age of 69.4 years (range 27–89 years). Oestrogen receptor and progesterone receptor expression levels were observed in 98.3 and 94.9% of cases, respectively. During the follow-up period, thrombotic events were documented in 21 (11.9%) of 177 patients receiving TAM and in 1 (2.5%) of 41 patients who did not receive tamoxifen. The estimated incidence was 51.9 per 1000 person-years and 21.5 per 1000 person-years, respectively. Notably, the highest risk was identified in the first 18 months, where 81% of the observed thrombotic events occurred. Patients aged older than 71 years had a significantly increased risk of thrombotic event under TAM treatment than their younger counterparts (p = 0.033). History of thrombotic event, cardiovascular and liver disease, as well as additional adjuvant treatment were not associated with increased thrombotic risk.ConclusionThe risk of thrombotic event in men treated with TAM for breast cancer is markedly increased in the first 18 months of treatment, and should be considered during treatment decisions.

Highlights

Male breast cancer (BC) is an uncommon disease and its rarity makes the performance of prospective randomised trials very difficult
In a recent retrospective study of 257 male BC patients, we showed that adjuvant treatment with TAM was associated with a
Via matching analysis among male and female patients with hormone receptor-positive breast cancer, we demonstrated clearly that the benefit of TAM treatment in male BC is comparable with the effect of TAM in female BC.[3]

Summary

Introduction

Male breast cancer (BC) is an uncommon disease and its rarity makes the performance of prospective randomised trials very difficult. Male BC appears to be hormone receptor (HR)-positive in most cases and endocrine therapy is the most important treatment option. In a recent retrospective study of 257 male BC patients, we showed that adjuvant treatment with TAM was associated with a. 1.4-fold decreased risk of cancer mortality compared to AI treatment.[2] Via matching analysis among male and female patients with hormone receptor-positive breast cancer, we demonstrated clearly that the benefit of TAM treatment in male BC is comparable with the effect of TAM in female BC.[3].

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