Breast cancer is the most common cancer in women. If the cancer has spread beyond the breast (metastatic disease), treatments include chemotherapy (anti-cancer drugs) and endocrine therapy (also known as hormonal treatment). Endocrine therapy is mainly given to women whose cancer is determined to be hormone-responsive, that is, where hormone receptors (oestrogen or progesterone receptors) are expressed in the tumour cells. The aim of this review was to see if starting treatment with chemotherapy or starting treatment with endocrine therapy provides more benefit in terms of survival, response to treatment, toxicity from treatment and quality of life. Ten eligible studies were identified, eight of which provided information on response to treatment (in 817 patients) and six on overall survival (in 692 patients). Trials were generally old (published between 1963 and 1995) and small in size (median of 70 women, range 50 to 226 women in each trial) and were of modest quality. The types of chemotherapy used were reasonably conventional by today's standards; the endocrine therapies varied considerably.
This review found that while initial treatment with chemotherapy rather than endocrine therapy may be associated with a higher response rate, the two initial treatments had a similar effect on overall survival. No single group of patients who might benefit from or be harmed by one treatment over the other were identified, although there was little information to address this question. Six of the seven fully published trials commented on increased toxicity associated with chemotherapy including nausea, vomiting and alopecia. Three of the seven trials mentioned aspects of quality of life but their findings provided differing results. Only one trial formally measured quality of life (QOL), concluding that QOL was better with chemotherapy. Based on these trials, no conclusions can be made as to the QOL achieved with either treatment.
Accurate information about hormone receptor status is now routinely available for many women with metastatic breast cancer, and hormonal treatments have improved in their effectiveness in the last 10 years. In women with metastatic breast cancer where hormone receptors are present, a policy of treating first with endocrine therapy rather than chemotherapy appears to be better, on the basis of the trials and outcomes in this review, except in the presence of rapidly progressive disease.