What is the management approach for multifocal Ductal Carcinoma In Situ (DCIS)?

Management of Multifocal Ductal Carcinoma In Situ (DCIS)

For patients with multifocal DCIS, mastectomy is the preferred treatment approach to minimize the risk of recurrence and invasive disease development, particularly when the extent of disease exceeds 4 cm. 1

Diagnosis and Initial Assessment

• Multifocal DCIS is most commonly detected as microcalcifications on mammography, requiring careful imaging evaluation before treatment planning 1
• Stereotactic core needle biopsy should be performed for suspicious nonpalpable mammographic abnormalities, with specimen radiography to confirm adequate sampling of microcalcifications 1
• Be aware that approximately 20% of DCIS cases diagnosed by percutaneous core needle biopsy will have areas of invasive carcinoma identified at the time of surgical excision 1
• Complete bilateral mammographic evaluation is essential, as bilateral DCIS has been reported in up to 19% of women 1

Surgical Management Options

Mastectomy

• Mastectomy remains the standard of care for multifocal DCIS, particularly when:
  • The extent of DCIS exceeds 4 cm 1
  • There is evidence of gross multicentricity or diffuse malignant calcifications 1
  • The disease cannot be completely excised with negative margins through breast conservation 1
  • The patient has a small breast where adequate resection would result in significant cosmetic deformity 1

Breast Conservation Considerations

• Breast conservation may be considered for selected cases of multifocal DCIS when:
  • The disease is localized without evidence of gross multicentricity 1
  • The extent of DCIS is ≤4 cm 1
  • Negative margins can be achieved 1
  • Complete removal of all malignant calcifications is confirmed by post-excision mammography 1

Management of the Axilla

• Routine axillary lymph node dissection is not recommended for pure DCIS as nodal metastases occur in fewer than 5% of cases 1
• Consider sentinel lymph node biopsy in:
  • Patients with large DCIS lesions where the risk of microinvasion is high 2
  • Extensive DCIS requiring mastectomy, since the procedure cannot be performed after mastectomy 1
  • Cases where invasion is suspected based on imaging or clinical findings 1

Radiation Therapy

• For patients with multifocal DCIS treated with breast conservation:
  • Radiation therapy should be delivered after surgical healing, typically within 2-4 weeks of uncomplicated breast-conserving surgery 1
  • Radiation significantly decreases the rate of local recurrence after lumpectomy 3
  • Radiation therapy is particularly important for multifocal disease due to the higher risk of recurrence 1

Adjuvant Systemic Therapy

• Tamoxifen 20 mg daily for 5 years is recommended for patients with estrogen receptor-positive DCIS 4
• Tamoxifen reduces the risk of invasive breast cancer by 43% in women with DCIS following breast surgery and radiation 4
• There is no established role for adjuvant chemotherapy in the management of DCIS 3

Follow-up Care

• Regular mammographic surveillance is essential after treatment for DCIS 1
• Clinical breast examination should be performed at regular intervals 1
• Patients should be monitored for potential recurrence, as approximately 50% of recurrences after breast-conservation therapy occur as invasive cancer 3

Important Considerations and Caveats

• The risk of recurrence after breast conservation is influenced by nuclear grade, presence of comedo necrosis, and margin involvement 3
• Following breast-conservation therapy for DCIS, about half of recurrences present as invasive cancer, which carries mortality risk 1
• The decision between mastectomy and breast conservation should consider the patient's preferences regarding body image, quality of life, and fear of recurrence 1
• Removal of lesions in multiple fragments should be avoided as this practice precludes margin assessment and size determination 1

Special Situations

• For patients with extensive high-grade DCIS or when a mass is present on mammogram, there is a higher likelihood of unrecognized invasive disease 1
• In patients with small breasts where adequate resection would result in poor cosmesis, mastectomy may be preferable 1
• For multifocal disease in different quadrants, mastectomy offers the most definitive treatment approach 1

By following these guidelines, clinicians can provide optimal management for patients with multifocal DCIS, balancing the goals of disease control and quality of life.