What is the recommended treatment approach for a patient presenting with a Phylloides tumor?

Treatment of Phyllodes Tumors

All phyllodes tumors—regardless of whether they are benign, borderline, or malignant—require surgical excision with tumor-free margins of at least 1 cm, and axillary lymph node dissection should never be performed as these tumors rarely metastasize to lymph nodes. 1

Surgical Management Algorithm

Primary Surgical Approach

• Lumpectomy or partial mastectomy is the preferred surgical therapy for all phyllodes tumor subtypes 1
• The critical surgical goal is achieving margins ≥1 cm, which is more important than histologic subtype for preventing local recurrence 1, 2
• Total mastectomy should be performed ONLY when negative margins cannot be obtained with breast-conserving surgery 1
• Mastectomy is specifically indicated for patients with large lesions where adequate margins are unachievable 2

What NOT to Do Surgically

• Do NOT perform axillary staging or lymph node dissection—this adds unnecessary morbidity without benefit, as phyllodes tumors rarely metastasize to axillary lymph nodes 1, 3
• Do NOT accept margins <1 cm, as local recurrence correlates directly with inadequate excision margins 2

Diagnostic Considerations Before Surgery

Clinical Presentation

• Phyllodes tumors present as rapidly enlarging, usually painless breast masses in women with a mean age in their 40s 1
• These tumors are clinically and radiographically indistinguishable from fibroadenomas on ultrasound and mammography 1

Critical Diagnostic Pitfall

• In the setting of a large (>2 cm) or rapidly enlarging clinical "fibroadenoma," excisional biopsy must be performed to pathologically exclude phyllodes tumor 1
• Core needle biopsy may not reliably distinguish phyllodes from fibroadenoma preoperatively 3
• When CNB suggests a potential phyllodes tumor, surgical excision is mandatory 4

Adjuvant Therapy Decisions

Radiotherapy

• Radiotherapy is NOT routinely recommended for all phyllodes tumors 1
• Consider radiotherapy ONLY for borderline or malignant tumors meeting these specific criteria: 1, 3
  • Tumor size >5 cm
  • Infiltrative margins
  • Cases where clear margins could not be achieved despite re-excision attempts
  • Local recurrence, especially if additional recurrence would create significant morbidity

Systemic Therapy

• Neither chemotherapy nor endocrine therapy has any proven role in phyllodes tumor treatment 1, 3
• Although 58% contain estrogen receptors and 75% contain progesterone receptors, endocrine therapy does not reduce recurrence or death 1
• No evidence demonstrates that adjuvant cytotoxic chemotherapy reduces recurrence or death 1

Management of Local Recurrence

• Re-excision with wide tumor-free surgical margins (≥1 cm) is recommended for local recurrence 1, 5
• Do NOT perform axillary staging even for recurrent disease 5
• Consider postoperative radiation therapy if additional recurrence would create significant morbidity 1, 5
• Local recurrence occurs in approximately 15% of patients and is more common after incomplete excision 6

Reconstruction Timing

• Immediate reconstruction should be avoided in borderline phyllodes tumors with high-risk features 1, 3
• Delayed reconstruction is preferred after primary oncological management is completed and local recurrence risk has diminished 1, 3

Multidisciplinary Management

• Borderline and malignant phyllodes tumors should be referred to specialist sarcoma centers for pathology review and multidisciplinary team discussion 1, 3
• Most distant recurrences occur in the lung and should be treated according to soft tissue sarcoma guidelines 1

Prognostic Factors

• Histologic subtype is an independent prognostic factor, with 5-year disease-free survival rates of 95.7% for benign, 73.7% for borderline, and 66.1% for malignant tumors 1
• However, margin status is more important than subtype for predicting local recurrence 1
• Tumor size >5 cm, mitotic rate ≥10/10 HPF, stromal overgrowth, and stromal cellularity predict disease-free survival 7