Age-specific nonpersistence of endocrine therapy in postmenopausal patients diagnosed with hormone receptor-positive breast cancer: a TEAM study analysis.
BACKGROUND
Early discontinuation of adjuvant endocrine therapy may affect the outcome of treatment in breast cancer patients. The aim of this study was to assess age-specific persistence and age-specific survival outcome based on persistence status.


METHODS
Patients enrolled in the Tamoxifen Exemestane Adjuvant Multinational trial were included. Nonpersistence was defined as discontinuing the assigned endocrine treatment within 1 year of follow-up because of adverse events, intercurrent illness, patient refusal, or other reasons. Endpoints were the breast cancer-specific and overall survival times. Analyses were stratified by age at diagnosis (<65 years, 65-74 years, ≥75 years).


RESULTS
Overall, 3,142 postmenopausal breast cancer patients were included: 1,682 were aged <65 years, 951 were aged 65-74 years, and 509 were aged ≥75 years. Older age was associated with a higher proportion of nonpersistence within 1 year of follow-up. In patients aged <65 years, nonpersistent patients had lower breast cancer-specific and overall survival probabilities. In patients aged 65-74 years and patients aged ≥75 years, the survival times of persistent and nonpersistent patients were similar.


CONCLUSIONS
Nonpersistence within 1 year of follow-up was associated with lower breast cancer-specific and overall survival probabilities in patients aged <65 years, but it was not associated with survival outcomes in patients aged 65-74 years or in patients aged ≥75 years. These results suggest that extrapolation of outcomes from a young to an elderly breast cancer population may be insufficient and urge age-specific breast cancer studies.
Leiden University Medical Center, Albinusdreef 2, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
Willemien
W
van de Water
Esther
E
Bastiaannet
Elysée T M
ET
Hille
Elma M
EM
Meershoek-Klein Kranenbarg
Hein
H
Putter
Caroline M
CM
Seynaeve
Robert
R
Paridaens
Anton J M
AJ
de Craen
Rudi G J
RG
Westendorp
Gerrit-Jan
GJ
Liefers
Cornelis J H
CJ
van de Velde
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000730:Androstadienes / Q000008:administration & dosage / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D015996:Survival Rate; D013629:Tamoxifen / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
D000730:Androstadienes; D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen; C056516:exemestane