What is the management plan for lobular carcinoma in situ (LCIS)?

Management of Lobular Carcinoma In Situ (LCIS)

Observation alone is the preferred management option for classic LCIS, as the risk of developing invasive carcinoma is relatively low (approximately 21% over 15 years) with favorable histologies of subsequent invasive cancers and low mortality rates. 1

Diagnostic Evaluation

• Complete pathologic review of all cases is recommended to distinguish LCIS from atypical hyperplasia or early invasive carcinoma
• Bilateral diagnostic mammography to identify multiple primary tumors and estimate extent of the lesion
• Genetic counseling if patient is at high risk for hereditary breast cancer

Management Options

Primary Management: Observation

• Observation alone is the preferred approach for most women with classic LCIS 1
• Complete surgical excision of the LCIS lesion is recommended 1
• No need to obtain clear surgical margins after excisional biopsy 1
• Regular surveillance with annual clinical breast examination and mammography

Risk Reduction Strategies

1. Chemoprevention:

   • Tamoxifen for premenopausal women (46% risk reduction) 1
   • Tamoxifen or raloxifene for postmenopausal women 1
   • Should be discussed as a risk reduction strategy for all women with LCIS who choose observation

2. Surgical Options:

   • Bilateral risk-reducing mastectomy is generally NOT recommended for most women with LCIS without additional risk factors 1
   • Consider bilateral risk-reducing mastectomy only in special circumstances:
     • BRCA1/2 mutation carriers
     • Strong family history of breast cancer
     • Patient preference after thorough multidisciplinary counseling

Special Considerations

• Pleomorphic LCIS may behave more like DCIS and should be treated accordingly after multidisciplinary discussion 1
• The risk of developing invasive breast cancer after LCIS is equal in both breasts, so if mastectomy is chosen, bilateral procedure is required 1
• Women treated with bilateral mastectomy are appropriate candidates for breast reconstruction 1

Clinical Pearls and Pitfalls

• LCIS is primarily a marker of increased risk rather than a direct precursor lesion 2, 3
• Subsequent invasive cancers may be of either ductal or lobular phenotype 2
• The risk of contralateral breast cancer is high (20-45%) 4
• Unlike DCIS, LCIS does not require obtaining negative margins after excision 1
• No role for cytotoxic chemotherapy in LCIS management 3
• Most subsequent invasive cancers occur more than 15 years after diagnosis, emphasizing the need for long-term surveillance 3
• A finding of LCIS does not mandate risk-reducing mastectomy, but this option should be discussed 1

Algorithm for Management Decision

1. Confirm diagnosis with pathologic review
2. Assess additional risk factors (family history, genetic mutations)
3. For classic LCIS:
   • Recommend observation with complete excision
   • Discuss chemoprevention with tamoxifen or raloxifene
   • Consider bilateral mastectomy only for high-risk patients or by patient preference
4. For pleomorphic LCIS:
   • Treat similarly to DCIS with more aggressive approach

The excellent prognosis of women with LCIS (whether managed with observation or bilateral mastectomy) should be emphasized when discussing management options 1.