What is the recommended treatment approach for a 77-year-old female patient with bilateral invasive mammary carcinoma that is estrogen receptor (ER) positive, progesterone receptor (PR) positive, and human epidermal growth factor receptor 2 (HER2NEU) negative?

Treatment Approach for 77-Year-Old Female with Bilateral ER+/PR+/HER2- Breast Cancer

The recommended treatment for this 77-year-old female with bilateral ER+/PR+/HER2- invasive breast cancer should focus on endocrine therapy as the primary intervention, with consideration of surgery based on tumor characteristics and patient factors.

Initial Assessment and Surgical Options

• For bilateral invasive breast cancer that is ER+/PR+/HER2-, surgical options include breast-conserving surgery (lumpectomy) with sentinel lymph node biopsy or mastectomy with sentinel lymph node biopsy, depending on tumor size, location, and patient preference 1
• If breast-conserving surgery is chosen, postoperative radiation therapy is strongly recommended to reduce local recurrence risk 1
• For patients ≥70 years with small ER+ tumors, some data suggest that radiation therapy may be omitted after breast-conserving surgery with minimal impact on overall survival, though recurrence-free survival is improved with radiation 2

Systemic Therapy Recommendations

• For postmenopausal women with ER+/PR+/HER2- breast cancer, endocrine therapy is the cornerstone of treatment 1, 3
• Aromatase inhibitors (anastrozole, letrozole, or exemestane) are preferred over tamoxifen in this age group as they have shown superior response rates and time to progression 1, 3
• The duration of endocrine therapy should be at least 5 years 1

Considerations for Adjuvant Chemotherapy

• In this 77-year-old patient with ER+/PR+/HER2- disease, the absolute benefit of adding chemotherapy to endocrine therapy may be small and should be weighed against potential toxicity 1
• Factors that would favor chemotherapy include higher tumor grade, larger tumor size (≥3 cm), or lymph node involvement 1
• If lymph nodes are positive (especially 4 or more positive nodes), adjuvant chemotherapy should be more strongly considered despite the patient's age 1

Radiation Therapy Guidelines

• After breast-conserving surgery, radiation therapy to the whole breast is generally recommended 1
• Post-mastectomy radiation therapy is indicated if there are 4 or more positive axillary lymph nodes 1
• Strong consideration should be given to post-mastectomy radiation therapy if there are 1-3 positive axillary lymph nodes 1
• For patients over 70 years with small, node-negative, hormone-positive tumors, omission of radiation therapy may be considered, though this is associated with a slightly higher local recurrence risk 2

Special Considerations for Elderly Patients

• Treatment decisions should consider the patient's physiological age rather than chronological age 1
• Bone health monitoring is important for women on aromatase inhibitors, with bone mineral density determination at baseline and periodically thereafter 1
• For patients with bone metastases (if present), bone-modifying agents should be added to reduce skeletal-related events 3

Follow-up Recommendations

• Clinical follow-up every 4-6 months for the first 5 years, then annually 1
• Annual mammography 1
• Regular assessment of adherence to endocrine therapy 1
• Monitoring for side effects of endocrine therapy, particularly bone health in patients on aromatase inhibitors 1

This treatment approach prioritizes disease control while considering quality of life in an elderly patient with a hormone-sensitive breast cancer subtype that typically has a more favorable prognosis compared to other breast cancer subtypes.