Breast cancer

Prescribing Notes:

General notes

• The position of specialist treatment in this condition pathway is not intended to guide on place in therapy. The place in therapy is directed by a consultant oncologist experienced in the management of breast cancer, use is in line with relevant local or national guidance. Refer to breast cancer formulary decisions and clinical management guidelines for more details.
• Duration of therapy and switching guidance will be communicated in letters from the specialist and will depend on whether treatment is neo-adjuvant, adjuvant (risk of recurrence), or for advanced or metastatic breast cancer. In risk of late recurrence of breast cancer in post-menopausal women, the duration of adjuvant treatment with tamoxifen or letrozole is 5 years beginning 5 years after the initial commencement of endocrine therapy.
• Endocrine therapy may cause a transient increase in bone pain in patients with bony metastases.

Tamoxifen

• Tamoxifen is offered to premenopausal women or men as a first-choice option with early breast cancer (curable setting).
• Patients who are peri-menopausal at initiation of adjuvant endocrine therapy and who have completed 2-3 years of tamoxifen may be switched to exemestane for the remainder of the 5-10 years on the recommendation of the specialist.
• Tamoxifen increases the risk of venous thrombosis.
• Tamoxifen increases the risk of endometrial cancer. Abnormal vaginal bleeding should be investigated promptly.

Aromatase inhibitors (AIs)

• Letrozole or anastrozole should be used as an alternative to tamoxifen in patients with an increased risk of thromboembolism.
• The aromatase inhibitors letrozole, anastrozole and exemestane are ineffective in premenopausal women unless a concomitant gonadorelin analogue is given to suppress ovarian function. Letrozole plus a gonadorelin analogue may be given where there is a contraindication to tamoxifen in pre-menopausal women or with higher risk cancers.
• If taken over a long period of time, AIs can cause osteoporosis.

Gonadorelin analogues

• Prostap 3 DCS is recommended as a gonadorelin analogue to be used as treatment in pre- and perimenopausal women with advanced breast cancer suitable for hormonal manipulation.
• Prostap 3 DCS is recommended as a gonadorelin analogue to be used as adjuvant treatment in combination with tamoxifen or an aromatase inhibitor, of endocrine responsive early-stage breast cancer in pre- and perimenopausal women at higher risk of disease recurrence (young age, high grade tumour, lymph node involvement). In women who have received chemotherapy, premenopausal status must be confirmed after completion of chemotherapy.
• Androgen suppression with gonadorelin analogues can cause menopause like symptoms including hot flushes, please refer for more information to treatment of hot flushes caused by androgen suppression for malignant disease.
• Oophorectomy is an alternative to a gonadorelin analogue in premenopausal women.
• For prescribing Gonadotrophin-releasing hormone (GnRH) analogue (any medicinal product that consists of or contains buserelin, gonadorelin, goserelin, leuprorelin acetate, nafarelin or triptorelin), please refer to Scottish Drug Tariff part 12 Schedule 2 ‘Drugs to be prescribed in certain circumstances under the NHS Pharmaceutical services’ for items that must be endorsed ‘SLS’.