Better Communication And Symptom Assessment Are Key To Promoting Adherence To Long-Term Hormonal Therapy For Invasive Breast Cancer

Main Category: Breast Cancer
Also Included In: Compliance
Article Date: 10 Sep 2008 - 4:00 PDT

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One in three women taking long-term hormonal (endocrine) therapy for invasive breast cancer stop their treatment before the end of the recommended five-year period, according to a major follow-up study, which reveals that women looked after in specialised oncology units are more likely to continue therapy than those cared for by family doctors.

Hormonal therapy has been recommended for the vast majority of post-menopausal women with hormone receptor positive breast cancer since the late 1990s. The female hormones oestrogen and progesterone drive the growth of these tumours, so switching off receptors for these hormones with hormonal therapy - either tamoxifen or aromatase inhibitors - is beneficial. Expert guidelines recommend that elderly women with hormone receptor positive breast cancer take tamoxifen for five years.

However, there are lots of reasons why it can be difficult for women to take hormonal therapy for this prolonged period of time after their breast cancer surgery. Previous research evaluating the use of adjuvant hormone therapy among postmenopausal breast cancer patients showed that between one in every six and one in every two (15-50%) women did not take, or adhere to, the treatment as recommended. Some women refused even to start hormone therapy

In the new study, a group of researchers from Basel, Switzerland, studied an unselected group of 325 postmenopausal women who were diagnosed with hormonal receptor-positive invasive breast cancer between 1997 and 2003. They looked carefully at the different clinical situations that led to the women stopping their hormonal treatment or simply not taking it exactly as recommended.

Results showed that only 191 of the 287 patients (66.6%) who started hormonal therapy for five years completed this treatment. Nearly two-thirds (206; 63.4%) of these women were initially prescribed tamoxifen, and the rest received an aromatase inhibitor.

Thirty-one patients (10.8%) chose independently to stop their hormonal therapy before the end of the recommended five years. The main reasons for non-adherence were general discomfort (29.0%), hot flushes (12.9%), skin symptoms and hair loss (9.7%), visual disturbance (3.2%) and alcohol dependency or psychiatric disease (9.7%). Just over one-third of these women did not give a reason for stopping their treatment. Nearly four in every ten (38.7%) of the women who stopped their hormonal therapy did so in the first year of treatment, while a further 19.4% stopped in the second year, and 29.0% in the third year.

A further 8.9% of the women refused the recommended endocrine therapy after extensive counselling and never even began this treatment. This was more likely in older women (P=0.019) and those who had early stage breast cancer (P=0.0546).

Experiencing side-effects with hormonal therapy is a common reason for not taking it as recommended. In the study, 25 patients changed their hormonal medication due to therapy-related adverse effects. Of these, 20 (80%) women fully completed their therapy after changing the drug they were prescribed.

Patients who had their follow-up care with a general practitioner were significantly more likely to be non-adherent than those looked after in an oncology unit (P=0.0088). Only one in ten (10.8%) of the women cared for by a specialised oncologic unit did not take their hormonal therapy as recommended.

The researchers concluded: "Our data show that, when compared with other studies, low non-adherence rates can be realistically achieved." They noted that this was probably associated with the fact that practitioners in specialist oncology units had received targeted education in patient-centred communication.

"In our view, non-adherence is not simply the act of stopping medication, but rather the manifestation of an intentional behaviour. The reasons for non-adherence, such as distressing adverse effects, inadequate clarification of the benefits of therapy, and fear and mistrust of the agent prescribed, can be elucidated in most cases," the researchers suggested. "An important aspect of non-adherence is the ability of the physician to intervene and change the attitude that led to discontinuation."

Commenting on the study, Nora Kearney, Professor of Cancer Care and Director of the Cancer Care Research Centre at the University of Stirling, Scotland, said: "I think the important issue that this paper raises - adherence to long-term treatment - has to be given more credence in the cancer community. This is largely because there is a shift in practice for many people with cancer, in that it is becoming a long-term condition. For this reason, long-term maintenance therapy, such as endocrine therapy in breast cancer, is becoming really important and much more of an issue than in the past." She added: "This is true not only for breast cancer but also for other cancers."

It is, therefore, very important that sufficient priority be given to ensuring the long-term impact of maintenance therapy, Professor Kearney suggested.

She noted that the new study dealt with the methodological limitations of previous studies. However, she cautioned: "It is still a retrospective analysis of case notes. While this uncovers some important issues, we need to move away from retrospective studies. We need to look at adherence in a prospective way, working with patients from the initiation of endocrine therapy and looking at adherence with drug therapy from the patient's perspective."

The study confirmed the key issues influencing adherence that have been seen in previous studies. These include age, educational level and access to information on the Internet. Involvement in decision-making about initiating therapy is also important, according to Professor Kearney. "However, many patients are getting insufficient information about the underlying reason for taking endocrine therapy and the need for adherence. They need to be given information on why it is important to take it in the first place and why they need to take the treatment on a long-term basis," she advised.

Patients should also be given information in advance about possible side-effects with long-term therapies. "We know that people on endocrine therapy get poor information on side-effects, which affects compliance," she said. "In addition, people should have information on recurrence, given in a very clear way. At the moment, this doesn't seem to be happening."

Professor Kearney warned that one of the major gaps - which hasn't been addressed in the initial therapy of cancer or in endocrine therapy - is the appropriate assessment of symptoms in patients with cancer. "This is poorly done for routine adjuvant therapy and this spills over into endocrine therapy. There is no systematic assessment of the symptoms associated with treatment, including endocrine therapy. We need to take a new look at systematic ways of assessing the symptoms associated with cancer treatments," she concluded.

Reference

Target and reality of adjuvant endocrine therapy in postmenopausal patients with invasive breast cancer.
Guth, U, Huang, DJ, Schotzau, A et al.
British Journal of Cancer 2008; 99: 428-433.

Cancer Research Summaries are overviews of important cancer research findings that have been reported in leading cancer publications. The Cancer Research Summaries are provided by the Cancer Media Service (CMS) in collaboration with Nature Clinical Practice Oncology.

"This summary is provided by The European School of Oncology's Cancer Media Service "

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