Breast cancer: hormone therapy has a greater impact on quality of life than chemotherapy

Analysis conducted by a team, with researchers from Paris-Sud University, has just challenged assumptions about the impact that hormone therapy and chemotherapy can have on the quality of life of women with breast cancer.

An analysis of the CANTO cohort has just shown that contrary to what is generally accepted, at two years from diagnosis, hormone therapy, which is an extremely effective treatment against breast cancer, has a longer and more detrimental impact on quality of life, particularly on that of menopausal women; the negative effects of chemotherapy are more transient.

At a time when the international recommendations are to prescribe hormone therapy for 5 to 10 years, it is important to offer treatment to women, who develop severe symptoms related to anti-hormone treatments, and to identify those who could benefit from a de- escalation of therapy.

“This analysis of the CANTO cohort shows for the first time that anti-hormone treatments do not have a lower impact than chemotherapy on women’s quality of life. In fact, the deterioration in quality of life, which is identified on diagnosis, persists for two years afterwards while the impact of chemotherapy is more transient,” states Dr. Vaz-Luis, an oncologist specializing in breast cancer and a researcher at Gustave Roussy Institute in the “Identification of New Therapeutic Targets in Oncology” Laboratory (Inserm/Paris-Sud University/Gustave Roussy Institute), who led the study.

In this study, researchers measured the quality of life of 4,262 patients with localized breast cancer (stage 1 to stage 3) at the time of diagnosis, at one year and then at two years. The treatment of these patients consisted of surgery and for some of them chemotherapy and/or radiotherapy. Around 75-80% of them then took hormone therapy for at least 5 years.

Key results for future treatment

An overall deterioration in quality of life was observed for the entire study population two years after diagnosis. This deterioration is greater in patients who have received hormone therapy, especially after the menopause. On the other hand, the impact of chemotherapy is greater on the quality of life of non-menopausal women, particularly on the deterioration in cognitive function.

“In future, it is essential that we are able to predict which women will develop severe symptoms with anti-hormone treatments in order to support them better,” adds Dr. Vaz-Luis.

While it has been proved that hormone therapy provides a real benefit in preventing the relapse of hormone-dependent cancers – which account for 75% of all breast cancers – the deterioration in quality of life can also have a negative effect on women's compliance with treatment. It is therefore important to provide them with treatment for symptoms with the greatest impact, particularly those related to the menopause, musculoskeletal pains, depression, severe fatigue, or even cognitive dysfunction, and to combine it with support care like physical exercise and cognitive behavioral therapies.

“In future, it will also be important to identify patients at high risk of relapse from those at lower risk before treatment. This will help to prevent the escalation of anti-hormone treatments,” concludes Dr. Vaz-Luis who recalls that, “hormone therapy is extremely effective against breast cancer. It enables a reduction of around 50% in the risk of relapse. In any event, the description of poor tolerance does not challenge the excellent risk/benefit ratio of this treatment.”

This study was supported by the National Research Agency, the Susan G. Komen Association, the ARC Foundation for Cancer Research, Odyssea and the Gustave Roussy Foundation.

The Canto cohort
Sponsored by Unicancer and led by Prof. Fabrice André, an oncologist specializing in breast cancer at Gustave Roussy Institute, Research Director at Inserm (National Institute for Health and Medical Research) and head of the “Identification of New Therapeutic Targets in Oncology” Laboratory (Inserm/Paris-Sud University/Gustave Roussy Institute), the CANTO cohort (for CANcer TOxicities) consists of 12,000 women with breast cancer treated in 26 French centers. Its aims to describe the toxicities associated with treatments, to identify populations likely to develop them and to subsequently adapt treatments to ensure a better post-cancer quality of life.


Differential impact of endocrine therapy and chemotherapy on quality of life of breast cancer survivors: a prospective patient-reported outcomes analysis
Annals of oncology, 8 October 2019