Minimal impact of adjuvant exemestane or tamoxifen treatment on mammographic breast density in postmenopausal breast cancer patients: a Dutch TEAM trial analysis.
BACKGROUND
Mammographic breast density is one of the strongest independent risk factors for developing breast cancer. We examined the effect of exemestane and tamoxifen on breast density in Dutch postmenopausal early breast cancer patients participating in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial.


METHODS
Analogue mammograms of selected TEAM participants before start, and after one and two (and if available after three) years of adjuvant endocrine therapy were collected centrally and reviewed. Study endpoints were change in breast density over time, and correlations between breast density and locoregional recurrence (LRR), distance recurrence (DR), and contralateral breast cancer (CBC).


RESULTS
Mammograms of 378 patients (181 tamoxifen, 197 exemestane) were included in the current per protocol analyses. Baseline breast density was low (breast density score<50% in 75% of patients) and not different between patients randomised to exemestane or tamoxifen (coefficient 0.16, standard error 0.17). Breast density did not change during treatment in exemestane (p=0.25) or tamoxifen users (p=0.59). No relation was observed between breast density and the occurrence of a LRR [hazards ratio (HR) 0.87, 95% CI 0.45-1.68, p=0.67], a DR (HR 1.02, 95% CI 0.77-1.35, p=0.90), or CBC (HR 1.31, 95% CI 0.63-2.72, p=0.48).


CONCLUSIONS
The in general low breast density score in early postmenopausal breast cancer patients did not substantially change over time, and this pattern was not different between tamoxifen and exemestane users. Breast density was not a predictive marker for efficacy of adjuvant endocrine therapy.
Department of Surgery, Leiden University Medical Centre , Leiden , The Netherlands.
Johanna G H
JG
van Nes
Louk V A M
LV
Beex
Caroline
C
Seynaeve
Hein
H
Putter
Alexandr
A
Sramek
Susanne
S
Lardenoije
Marjolijn
M
Duijm-de Carpentier
Inge
I
Van Rongen
Johan W R
JW
Nortier
Harmien M
HM
Zonderland
Cornelis J H
CJ
van de Velde
D000368:Aged; D000369:Aged, 80 and over; D000730:Androstadienes / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D000071060:Breast Density; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant / Q000379:methods; D004965:Estrogen Antagonists / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D042361:Mammary Glands, Human / Q000002:abnormalities* / Q000187:drug effects; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D017698:Postmenopause; D011859:Radiography; D013629:Tamoxifen / Q000627:therapeutic use*; D016896:Treatment Outcome
D000730:Androstadienes; D018931:Antineoplastic Agents, Hormonal; D004965:Estrogen Antagonists; D013629:Tamoxifen; C056516:exemestane