In a controlled trial, premenopausal women receiving chemotherapy for breast cancer were less likely to have early menopause if they received concurrent triptorelin treatment to produce temporary ovarian suppression.

Breast cancer in younger women is less common, about 12% aged under 45 years, but they are at increased risk of an adverse outcome and therefore most will receive intensive systemic chemotherapy. This may cause early ovarian failure leading to premature menopause: it is estimated that each month of chemotherapy translates into 1.5 years of lost reproductive life. There are no proven standard strategies for preventing this toxicity, however experimental work and pilot studies suggest that suppressing ovarian function with a gonadotropin-releasing hormone (GnRH) analogue might be helpful. This trial examined the hypothesis.

Participants were women aged 18 to 45 with proven breast cancer who were candidates for adjuvant or neoadjuvant chemotherapy, had not previously received any chemotherapy, and were premenopausal. They were randomised before start of chemotherapy to receive chemotherapy alone or combined with open label triptorelin, which was given 1 week before the chemotherapy course started and continued every four weeks until the course finished. The primary outcome measure was the incidence of early menopause at one year after the end of chemotherapy. Power calculations indicated that 280 participants would be adequate to detect a 20% absolute reduction in early menopause in the triptorelin group.

There were 281 women randomised into the study, 148 receiving triptorelin and 133 controls: 8 did not receive the intervention as randomised due to refusal (6 and 2 respectively), however analysis was by intention to treat using imputed values for missing data.

At 12 months, patients in the triptorelin group were less likely to have had early menopause compared to the control group, 8.9% vs. 25.9% respectively (absolute difference −17%; 95% CI, −26% to −7.9%; P < .001). On multivariate analysis, triptorelin was associated with a significant decrease in risk of early menopause, with an odds ratio of 0.28 (95% CI, 0.14 to 0.59; P < .001).

There were no significant additional adverse effects likely to be attributable to the triptorelin.

The authors conclude that in this study, temporary ovarian suppression using the GnRH analogue triptorelin was effective in reducing the risk of early menopause in younger women having chemotherapy for breast cancer. They note that the incidence of early menopause in their study was much lower than expected probably because they used a stricter definition. Patients who received tamoxifen were more likely to have amenorrhoea. They note some limitations of their study, and summarise the existing work; they also address some of the potential concerns over GnRH agonist treatment during chemotherapy for breast cancer. Overall, they conclude that temporary ovarian suppression using triptorelin reduces the incidence of chemotherapy-induced early menopause, and therefore suggest that this option can be offered to premenopausal breast cancer patients who are concerned over the possibility of early menopause.

An accompanying editorial discusses the trial: the authors are more cautious in their recommendation than those of the study, however they still consider that GhRH agonist therapy could be a useful option for patients with hormone-insensitive disease.