What is the adjuvant management for a 67-year-old male with Estrogen Receptor (ER) positive Ductal Carcinoma In Situ (DCIS) resected with clear margins?

From the Guidelines

For a 67-year-old male with ER-positive ductal carcinoma in situ (DCIS) resected with clear margins, I recommend adjuvant endocrine therapy with tamoxifen 20 mg daily for 5 years, as supported by the most recent guideline update from 2020 1. This treatment reduces the risk of both ipsilateral breast recurrence and contralateral breast cancer development. Alternatively, an aromatase inhibitor such as anastrozole 1 mg daily for 5 years could be considered, particularly if there are contraindications to tamoxifen such as history of thromboembolic events or if the patient has severe osteoporosis, as suggested by the 2018 NCCN guidelines 1. Radiation therapy should also be discussed, typically delivered as whole breast radiation with a total dose of approximately 40-50 Gy in 15-25 fractions, though it may be omitted in selected low-risk cases with small, low-grade DCIS with wide margins, in line with the recommendations from the 2024 ESMO clinical practice guideline 1. The decision for radiation should be individualized based on the extent of DCIS, grade, and patient preferences. Endocrine therapy works by blocking estrogen stimulation of any residual cancer cells, while radiation eliminates microscopic disease that might remain after surgery. Regular follow-up with clinical breast exams every 6-12 months and annual mammography is essential regardless of the adjuvant treatment chosen, as emphasized by the 2020 study on lumpectomy margins for invasive breast cancer and DCIS 1. Key considerations include:

• The patient's age and overall health status
• The presence of any comorbidities that may impact treatment tolerance
• The patient's preferences and values regarding treatment options
• The potential benefits and risks of each treatment approach, including the impact on quality of life. It is essential to weigh these factors carefully and engage in a thorough discussion with the patient to determine the most appropriate treatment plan.

From the FDA Drug Label

In women with DCIS, following breast surgery and radiation, tamoxifen citrate tablets are indicated to reduce the risk of invasive breast cancer The decision regarding therapy with tamoxifen for the reduction in breast cancer incidence should be based upon an individual assessment of the benefits and risks of tamoxifen therapy. Current data from clinical trials support 5 years of adjuvant tamoxifen therapy for patients with breast cancer Ductal Carcinoma in Situ (DCIS) The recommended dose is tamoxifen 20 mg daily for 5 years.

For a 67-year-old male with ER-positive DCIS resected with clear margins, tamoxifen may be considered as an adjuvant treatment. The recommended dose is 20 mg daily for 5 years 2 2. However, it is essential to note that the majority of the data on tamoxifen is from studies in women, and the benefits and risks in men may differ.

• Key considerations:
  • The patient's estrogen receptor (ER) status is positive, which may indicate a potential benefit from tamoxifen therapy.
  • The patient has undergone resection with clear margins, which is an important factor in determining the risk of recurrence.
  • The patient is male, and the data on tamoxifen in men is limited compared to women. It is crucial to weigh the potential benefits and risks of tamoxifen therapy in this patient and consider individual factors before making a decision.

From the Research

Adjuvant Management for ER-Positive DCIS

• The role of adjuvant endocrine therapy after surgical excision of ductal carcinoma in situ (DCIS) has been debated, with some studies suggesting its use in high-risk estrogen receptor-positive DCIS 3.
• A study published in 2018 found that there is no scientific evidence that adjuvant endocrine therapy reduces the incidence of ipsilateral breast invasive recurrence or breast cancer mortality in the context of adequate local treatment of DCIS 3.
• However, adjuvant endocrine therapy can be considered after a rigorous multidisciplinary discussion and patient counselling in a carefully selected subgroup of patients with high-risk estrogen receptor-positive DCIS 3.

Initiation and Adherence to Adjuvant Endocrine Therapy

• A study published in 2017 found that approximately 45% of women with ER-positive DCIS initiated treatment with tamoxifen or aromatase inhibitors within 1 year of their DCIS diagnosis, with adherence decreasing from 67% in the first year to 30% in the fifth year 4.
• Factors associated with initiation of hormone therapy included age, geographic location, education, marital status, diagnosis year, and race/ethnicity 4.
• Another study published in 2016 found that younger women were more likely to initiate endocrine therapy, and that women who had breast-conserving surgery with radiation were more likely to use endocrine therapy than those who had breast-conserving surgery alone or mastectomy 5.

Efficacy of Aromatase Inhibitors in DCIS

• A study published in 2007 found that aromatase inhibitors are likely to be effective in DCIS, with significant effects on reducing PgR expression and proliferation in DCIS lesions 6.
• Another study published in 2015 found that aromatase inhibitors may mitigate the incidence of tamoxifen-associated endometrial cancer, with a 48% lower incidence of endometrial cancer in the aromatase inhibitor group compared to the tamoxifen group 7.

Considerations for Adjuvant Management

• The decision to use adjuvant endocrine therapy in patients with ER-positive DCIS should be individualized, taking into account the patient's risk factors, tumor characteristics, and personal preferences 3, 4, 5.
• Aromatase inhibitors may be a viable option for patients with ER-positive DCIS, particularly those who are at high risk of recurrence or who have contraindications to tamoxifen 6, 7.