A new Danish study shows that women with breast cancer who live alone or are not working more often discontinue adjuvant endocrine therapy (AET). Previous research suggests that women who prematurely discontinue AET have an increased risk of recurrence, so determining how these women can benefit from support programmes to enhance AET adherence is important.
AET is a regular part of treatment for many women with estrogen receptor–positive breast cancer. Adhering to AET for at least the recommended five years is therefore important.
However, a new study shows that, although most women with breast cancer in Denmark adhere to AET, this may be more difficult for women living alone and women not working.
These two groups more often discontinue AET. According to the researchers behind the study, efforts need to be made to help women continue their treatment for the assigned duration.
“We may have to develop support programmes adapted to the women who are most in need. Far from everyone living alone or not working faces challenges with adhering to AET, but our study highlights some groups who may need additional help,” explains Julie A. Schmidt, Postdoctoral Fellow, Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, Denmark.
The research has been published in the Journal of Clinical Oncology.
Data from more than 4,000 women with breast cancer
The study was led by researchers from the Department of Clinical Epidemiology at Aarhus University and Aarhus University Hospital in collaboration with the Danish Breast Cancer Group and the Department of Oncology at Rigshospitalet and the University of Copenhagen. It examined data on 4,353 premenopausal women diagnosed with breast cancer between 2002 and 2011 in Denmark.
The researchers used Denmark’s registries to determine whether the women lived alone, whether they were employed, their education level and their household income.
They used the Danish Breast Cancer Group’s database to estimate whether the women adhered to AET for up to five years after diagnosis.
“Women with estrogen receptor–positive breast cancer are recommended to complete AET to avoid increasing the risk of recurrence. Determining whether some women have more difficulty adhering to AET than others is therefore important,” says Julie A. Schmidt.
Two groups discontinue AET more often
The study shows that women with breast cancer in Denmark generally adhere to AET, with 83% adhering to AET for the full five years without interruption, which is a high percentage compared with many other countries. Nevertheless, 17% still discontinued early.
The researchers found that women living alone had a 48% higher probability of discontinuing AET than cohabiting women. Women not working had a 44% higher probability of discontinuing AET than employed women.
“Our results are substantiated by similar findings in smaller studies from outside Denmark. Women living alone and women not working are two groups worth focusing on. The fact that there is disparity between those who complete AET and those who do not gives cause for concern,” notes Julie A. Schmidt.
Greater focus on specific groups of women with breast cancer
Although the data are from 2002 to 2011, Julie A. Schmidt thinks that the situation would be similar today.
She therefore suggests that measures be taken to support these two groups of women in adhering to AET, so that they do not have increased risk of recurrence and its serious effects.
According to Julie A. Schmidt, specific support programmes should be designed to benefit the women who most need help.
More studies on the way
The researchers behind the study would like to carry out more studies based on the results.
They would like to investigate which other characteristics are associated with whether women discontinue AET and how these groups of women fare after being diagnosed with breast cancer. Do they experience more frequent relapses, and how does this affect their risk of dying from breast cancer?
Finally, the researchers would like to expand the study to include women diagnosed with breast cancer after menopause, which is a larger group and involves women receiving a different type of AET.
“Our research group has a major focus on investigating which groups of women with breast cancer discontinue AET and what this means for their prognosis. This is an important area that we need to learn more about because it concerns many women and because it can affect equity in health,” concludes Julie A. Schmidt.
