Triptorelin: A Review of its Use as an Adjuvant Anticancer Therapy in Early Breast Cancer

A 1-month formulation of the gonadotrophin-releasing hormone agonist (GnRHa) triptorelin (Decapeptyl^®) has been approved in the EU as an adjuvant treatment in combination with tamoxifen or an aromatase inhibitor (AI), of endocrine-responsive, early-stage breast cancer in women at high risk of recurrence who are confirmed as premenopausal after completion of chemotherapy. This indication reflects the results of the 5-year SOFT and TEXT studies, especially SOFT, in which ovarian function suppression (OFS; mainly achieved with triptorelin) added to tamoxifen provided a significant benefit in the overall study population of premenopausal patients only after adjusting for prognostic factors. It emerged that adding OFS to tamoxifen produced more pronounced benefits in terms of disease control and, furthermore, increased overall survival in the cohort of higher-risk patients who had previously received chemotherapy. Also, compared with tamoxifen alone, the combination of OFS plus exemestane produced more pronounced benefits in terms of disease control than OFS plus tamoxifen. OFS induces premature menopause; when combined with either tamoxifen or exemestane, it increased the endocrine symptom burden. Nonetheless, the two combinations had distinct tolerability profiles (e.g. vasomotor symptoms and thromboembolic events were more frequent with OFS plus tamoxifen, whereas musculoskeletal symptoms, decreased libido, osteoporosis and fractures were more frequent with OFS plus exemestane). Thus, the combinations of OFS (with triptorelin) plus either tamoxifen or an AI are valid options for the adjuvant treatment of endocrine-responsive, early-stage breast cancer in women at sufficiently high risk of relapse to warrant receiving chemotherapy and who remain premenopausal thereafter. Individualized weighing of the potential benefits and adverse effects of treatment is required.