What is the current treatment approach for phyllodes tumors?

Current Treatment Approach for Phyllodes Tumors

Wide local excision with ≥1 cm margins is the standard primary treatment for all phyllodes tumors, regardless of grade, without axillary staging. 1

Diagnosis and Classification

• Phyllodes tumors are rare breast neoplasms that can be classified as:

  • Benign (50%)
  • Borderline (27%)
  • Malignant (23%) 2

• Diagnostic evaluation includes:

  • History and physical examination
  • Ultrasound
  • Mammogram for women ≥30 years
  • Core needle biopsy 1

• Clinical suspicion should arise with:

  • Palpable breast mass
  • Rapid growth
  • Large size (>2 cm)
  • Ultrasound findings similar to fibroadenoma but with larger size or growth history 1

Surgical Management

Primary Approach

• Wide local excision with ≥1 cm margins is the standard for all grades 1
• No axillary staging is recommended as lymph node involvement is rare 1
• Mastectomy should be considered only if negative margins cannot be achieved with breast conservation 1

Margin Status

• Optimal surgical margins of ≥1 cm are recommended to minimize recurrence risk 1
• Re-excision to achieve negative margins is recommended when possible for tumors with positive or narrow margins (<1 cm) 1
• Local recurrence correlates with excision margins (p<0.05), but not with tumor grade or size 3

Adjuvant Therapy

Radiation Therapy

• Adjuvant radiation therapy should be considered for:

  • Malignant phyllodes tumors
  • Large tumors (>5 cm)
  • Close (<5 mm) or positive margins
  • Multifocal or recurrent disease 1

• Recent evidence shows adjuvant radiation therapy significantly improves local recurrence-free survival in borderline/malignant phyllodes tumors (90% vs. 42% at 5 years, p=0.005) 4

• Patients with benign phyllodes tumors have excellent prognosis without adjuvant treatment after margin-negative resection 4

Chemotherapy and Endocrine Therapy

• Adjuvant chemotherapy has no proven role in reducing recurrence or mortality 1
• Despite high ER/PR expression in the epithelial component, endocrine therapy has no established role in management 1

Management of Recurrent and Metastatic Disease

• Re-excision with wide margins without axillary staging is recommended for recurrent disease 1
• Postoperative radiation should be considered for recurrent cases 1
• For metastatic disease, treatment protocols should follow those for soft tissue sarcoma 1

Prognostic Factors and Recurrence

• Local recurrence rates range from 23-27% 2, 5
• Risk factors for recurrence include:
  • Younger age
  • Malignant histology 5
  • Positive or close margins 3
• Multicentricity occurs in about 20% of borderline and malignant PTs but only in 5% of benign PTs 6

Follow-up and Reconstruction

• Regular surveillance is essential as most recurrences occur within the first few years 1
• Breast reconstruction should be considered as a delayed rather than immediate procedure, particularly for large malignant tumors that may require postoperative radiation 1

Common Pitfalls and Caveats

1. Diagnostic challenges: Core needle biopsy and FNA are often inadequate to distinguish phyllodes tumors from fibroadenomas 1

2. Margin assessment: Intraoperative frozen section analysis correlates with definitive histology in about 74% of cases, but may still miss positive margins 2

3. Recurrence management: Consider mastectomy early for recurrent borderline or malignant phyllodes tumors 6

4. Progression potential: Some borderline tumors can progress to malignant tumors upon recurrence 6