What adjuvant therapy is recommended for a 36-year-old woman with T1a, Node (N)0, Estrogen Receptor (ER) positive, Human Epidermal growth factor Receptor 2 (HER2) negative breast cancer?

From the Guidelines

For a 36-year-old woman with T1a N0 ER-positive HER2-negative breast cancer, I recommend tamoxifen 20 mg daily for 5-10 years as the primary adjuvant treatment, given her premenopausal status and the tumor's favorable prognosis. This recommendation is based on the latest guidelines and evidence from studies such as 1, which suggest that endocrine therapy is the primary treatment for ER-positive breast cancer, and that tamoxifen is a suitable option for premenopausal women. The patient's young age and the tumor's characteristics, including its small size (T1a) and negative lymph nodes, indicate a low risk of recurrence, and therefore, chemotherapy is not recommended as part of the initial treatment plan 1. However, the patient's age and the tumor's biology may warrant consideration of extended endocrine therapy, and the decision to extend treatment beyond 5 years should be made on an individual basis, taking into account the patient's preferences, risk of recurrence, and potential side effects of treatment 1. Regular monitoring and follow-up are essential to assess the patient's response to treatment and to address any potential side effects or concerns. The patient should be counseled about the potential benefits and risks of extended endocrine therapy, including the prevention of late recurrence and contralateral breast cancer, as well as the potential side effects, such as hot flashes, vaginal dryness, and mood changes 1. Ultimately, the decision to extend treatment beyond 5 years should be made through a shared decision-making process between the patient and her healthcare provider, taking into account the latest evidence and guidelines, as well as the patient's individual needs and preferences.

From the FDA Drug Label

Tamoxifen citrate tablets are indicated for the treatment of axillary node-negative breast cancer in women following total mastectomy or segmental mastectomy, axillary dissection, and breast irradiation The estrogen and progesterone receptor values may help to predict whether adjuvant tamoxifen therapy is likely to be beneficial. Current data from clinical trials support 5 years of adjuvant tamoxifen therapy for patients with breast cancer

For a 36-year-old woman with T1a N0 ER positive HER2 negative breast cancer, the recommended adjuvant therapy is tamoxifen for 5 years 2, 2.

• The patient's estrogen receptor positive status suggests that she may benefit from tamoxifen therapy.
• The patient's node-negative status and early-stage breast cancer suggest that 5 years of adjuvant tamoxifen therapy may be sufficient.
• Tamoxifen has been shown to reduce the occurrence of contralateral breast cancer in patients receiving adjuvant tamoxifen therapy for breast cancer.

From the Research

Adjuvant Therapy for ER Positive HER2 Negative Breast Cancer

• For a 36-year-old woman with T1a No ER positive HER2 negative breast cancer, adjuvant endocrine therapy (ET) is the cornerstone treatment 3.
• The choice of adjuvant therapy depends on the risk category, with low-risk patients typically receiving five years of ET, and high-risk patients receiving ET plus/minus ovarian function suppression (OFS) with two years of Abemaciclib 3.
• For premenopausal women, Tamoxifen is the preferred selection, while for postmenopausal patients, aromatase inhibitors (AIs) such as anastrozole, letrozole, or exemestane are the choice 3, 4.
• AIs have been shown to be superior to tamoxifen in terms of time to disease progression in patients with hormone receptor positive status 5.
• The optimal duration of AI therapy is undetermined, but an additional two to three years beyond the initial five years may be sufficient 3.
• Bisphosphonate is endorsed for postmenopausal patients 3.
• Comorbidity and demographics can influence the initial choice of therapy, with women with osteoporosis being less likely to commence anastrozole, and women with arthritis being more likely to commence letrozole 6.

Factors Influencing Adjuvant Therapy Choice

• Tumor size and menopause status at diagnosis can influence the choice of therapy, with tamoxifen being more often initiated in women with tumors >1 cm, and anastrozole being the predominant therapy for post-menopausal women 6.
• Subsidy restrictions can also influence therapy choice, with changes in restrictions leading to substantial increases in the proportion of women commencing AIs 6.
• The side effect profiles of different therapies can also impact choice, with AIs being associated with vasomotor symptoms, vaginal dryness, and bone loss, but lacking the estrogenic activity of tamoxifen 4.