MKSAP Quiz: Consultation following a diagnosis of breast cancer
A 70-year-old woman undergoes consultation following a diagnosis of breast cancer. She has no other medical conditions. Following a biopsy and lumpectomy, what is the most appropriate adjuvant treatment or management for this patient?
A 70-year-old woman undergoes consultation following a diagnosis of breast cancer. She has no other medical conditions.
Core biopsy of a left breast mass revealed grade III, estrogen receptor–positive, progesterone receptor–positive, and human epidermal growth factor receptor 2–positive invasive ductal carcinoma. Left lumpectomy revealed invasive ductal carcinoma measuring 1.9 cm in size. Two sentinel nodes were negative.
Which of the following is the most appropriate adjuvant treatment or management for this patient?
A. Chemotherapy and anti-human epidermal growth factor receptor 2–antibody,
breast irradiation, and endocrine therapy
B. Endocrine therapy
C. Obtain a gene expression profile
D. Radiation therapy followed by endocrine therapy
MKSAP Answer and Critique
The correct answer is A. Chemotherapy and anti-human epidermal growth factor receptor 2–antibody, breast irradiation, and endocrine therapy. This item is Question 67 in MKSAP 19's Oncology section. More information about MKSAP is available online.
This patient should be treated with chemotherapy and anti-human epidermal growth factor receptor 2 (HER2) therapy, breast irradiation, and endocrine therapy (Option A). This patient has had breast-conserving surgery and as a result needs postsurgical irradiation. Postsurgical irradiation decreases both the risk of local recurrence and the risk of distant metastases, and it increases overall survival. Whereas older women with small estrogen receptor (ER)–positive/HER2-negative tumors may consider omission of radiation therapy, HER2 positivity is a risk factor for local recurrence, and radiation therapy is recommended in this setting. Endocrine therapy is associated with a 40% reduction in risk of recurrence, and tamoxifen or an aromatase inhibitor is recommended for postmenopausal women with ER-positive breast cancer. Adjuvant chemotherapy combined with HER2-targeted treatment, such as the monoclonal antibody trastuzumab, is recommended for HER2-positive cancers. Women with small HER2-positive breast cancers can be treated with weekly paclitaxel and trastuzumab, and in this setting, outcomes are excellent with a risk of distant recurrence under 2% and a very favorable toxicity profile.
Adjuvant endocrine therapy alone or combined with radiation therapy (Options B, D) will not provide the same benefit of reducing the risk of recurrence or improving survival as does the combination of irradiation, chemotherapy, HER2-targeted therapy, and endocrine therapy for this patient. Although older patients may experience more adverse effects, treatment should not be omitted in the absence of comorbid conditions (severe cardiomyopathy) that would preclude anti-HER2 therapy.
Gene expression profiles such as the Oncotype DX Recurrence Score (Option C) are not used to inform treatment decision making for patients with HER2-positive breast cancer. The Recurrence Score is used to determine which patients with ER-positive/HER2-negative breast cancer benefit from chemotherapy. Patients with node-negative ER-positive/HER2-negative breast cancer and low or intermediate risk Recurrence Scores generally do not benefit from chemotherapy, whereas patients with high-risk Recurrence Scores generally do benefit from chemotherapy. HER2-positive breast cancer itself is associated with a higher risk of recurrence but also with substantial benefit from chemotherapy and anti-HER2 therapy (trastuzumab).
Key Point
- Adjuvant chemotherapy combined with human epidermal growth factor receptor 2 (HER2)–targeted treatment, such as the monoclonal antibody trastuzumab, is recommended for HER2–positive breast cancers.