Many breast cancer patients abandon endocrine treatment too soon, say researchers who suggest doctors use each consult to reinforce compliance messages.

Clinical trials have shown that endocrine therapy halves the risk of recurrence and reduces cancer-related mortality in women with hormone-dependent primary breast cancer when taken for five years or longer, but research has shown that up to 60% of women abandon therapy early, wrote Derrick Lopez from the School of Population and Global Health in Perth and colleagues in their paper published this month in Public Health Research and Practice.

Drawing from the Sax Institute’s 45 and Up study cohort the researchers assessed 261 women with primary breast cancer who had discontinued anastrozole, exemestane, letrozole or tamoxifen treatment one to four years following their diagnosis.

These women were then compared with similar women from the same cohort who did not discontinue endocrine therapy.

The research team found that women who consulted with a GP, surgeon or oncologist, and those who had a breast ultrasound or mammogram, were just as likely to discontinue the therapy within 30 days as those who did not.

But women who discontinued treatment were less likely to consult with a GP or specialist over the next six months.

“This perhaps emphasises the need for every clinical contact, including those where investigation results are discussed, to be used as an opportunity for discussion with the patient about the importance of ongoing endocrine therapy for at least the first 5 years (as is recommended in current clinical guidelines or possibly longer,” the researchers said.

Seventy-nine per cent of women who stopped the therapy had consulted with their GP over the following six months, the figure considerably higher than for other clinician types.

This suggests GPs have a key role to play in encouraging women to stick with pharmacotherapy, they wrote.

“However, there needs to be mechanisms in place to prompt clinicians to do this at every visit and to contact women who have not had a recent consult.”