What are the treatment options for breast cancer?

Treatment Options for Breast Cancer

Breast cancer treatment should be based on tumor characteristics, disease stage, and patient factors, with a multidisciplinary approach integrating local and systemic therapies to maximize survival and quality of life. 1

Classification and Diagnosis

• Breast cancer is classified into:
  • Non-invasive: Ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (CLIS)
  • Invasive: Stages I, II, and some IIIA 1
• Diagnosis requires:
  • Clinical examination
  • Bilateral mammography
  • Ultrasound
  • Biopsy for pathological confirmation
  • Determination of estrogen/progesterone receptors and HER2 status
  • TNM classification and histological grade 1

Treatment by Stage

Non-invasive Breast Cancer (Stage 0)

• DCIS (Ductal Carcinoma In Situ):
  • Breast-conserving surgery with radiation therapy OR mastectomy 1
  • For estrogen receptor-positive DCIS: Consider tamoxifen for risk reduction 2, 1
• CLIS (Lobular Carcinoma In Situ):
  • Complete resection due to risk of developing invasive cancer 1

Early Invasive Breast Cancer (Stages I, IIa, IIb)

1. Surgical Options:

   • Breast-conserving surgery (lumpectomy) with radiation therapy OR
   • Mastectomy (if patient refuses conservative treatment or widespread microcalcifications) 3, 1
   • Axillary lymph node assessment (sentinel lymph node biopsy) 3

2. Radiation Therapy:

   • Mandatory after breast-conserving surgery 3, 1
   • Additional boost to tumor bed for patients under 50 years 3
   • Post-mastectomy radiation for high-risk features (≥4 positive nodes) 1

3. Systemic Therapy Based on Tumor Subtype:

   • Hormone Receptor-Positive:
     • Premenopausal: Tamoxifen ± ovarian suppression 1, 2
     • Postmenopausal: Aromatase inhibitors or tamoxifen 1, 2
   • HER2-Positive: Trastuzumab with chemotherapy 1, 4
     • FDA-approved for adjuvant treatment of HER2-overexpressing node-positive or high-risk node-negative breast cancer 4
   • Triple-Negative: Chemotherapy (anthracyclines, taxanes) 1

Locally Advanced Breast Cancer (Stages IIIa, IIIb, IIIc)

• Neoadjuvant therapy (pre-surgery) to shrink tumor:
  • Chemotherapy for triple-negative or HER2-positive disease
  • Endocrine therapy for hormone receptor-positive disease 1
• Surgery after response to neoadjuvant therapy
• Post-surgery radiation therapy
• Adjuvant systemic therapy based on tumor subtype 1

Metastatic Breast Cancer (Stage IV)

• Not curable but treatable with goals of improving quality of life and prolonging survival 1, 5
• Treatment options:
  • Hormone Receptor-Positive: Endocrine therapy (tamoxifen, aromatase inhibitors) ± targeted agents 1, 2
  • HER2-Positive: Trastuzumab with chemotherapy 1, 4
    • FDA-approved in combination with paclitaxel for first-line treatment or as single agent after prior chemotherapy 4
  • Triple-Negative: Chemotherapy, consider immunotherapy 1
  • Bisphosphonates for bone metastases 1

Special Considerations

Occult Breast Cancer

• For patients with axillary metastases but no primary breast tumor:
  • MRI recommended to identify occult primary lesion 3
  • If MRI-positive: Further evaluation with ultrasound or MRI-guided biopsy 3
  • If MRI-negative: Options include mastectomy plus axillary nodal dissection OR axillary nodal dissection plus whole-breast irradiation 3

Fertility Preservation

• Discuss fertility preservation options with young premenopausal patients before starting systemic treatment 1

Treatment Selection Pitfalls

1. Avoid undertreatment of high-risk disease: Ensure appropriate adjuvant therapy for node-positive or aggressive tumor biology
2. Avoid overtreatment of low-risk disease: Consider tumor biology beyond just stage
3. Don't base treatment solely on age: Functional status and comorbidities should be considered alongside age 1
4. Don't neglect biomarker testing: Treatment decisions should be guided by ER/PR status, HER2 status, and potentially other biomarkers 1, 3
5. Don't delay treatment: Timely initiation of appropriate therapy is crucial for optimal outcomes

Response Evaluation

• Evaluate response after 3 months of endocrine therapy or 2-3 cycles of chemotherapy 1
• For metastatic disease, regular monitoring of treatment response is essential

Breast cancer treatment has evolved significantly with improved understanding of tumor biology. The integration of targeted therapies based on molecular subtypes has dramatically improved outcomes for many patients, making individualized treatment approaches based on tumor characteristics the standard of care.