What is the treatment for Lobular Carcinoma In Situ (LCIS)?

Treatment for Lobular Carcinoma In Situ (LCIS)

Observation alone is the preferred treatment option for women diagnosed with pure LCIS, as their risk of developing invasive carcinoma is relatively low (approximately 21% over 15 years). 1

Primary Management Options

Observation (Preferred Approach)

• Observation is recommended as the standard management for most women with LCIS because:
  • The risk of developing invasive carcinoma is relatively low 1
  • Histologies of subsequent invasive carcinomas tend to be favorable 1
  • Deaths from secondary invasive cancers are unusual in appropriately monitored women 1
  • LCIS is considered a marker of increased risk rather than a direct precursor to invasive cancer 2

Risk Reduction Strategies

• Chemoprevention:

  • Tamoxifen for premenopausal women: Associated with approximately 46% reduction in risk of developing invasive breast cancer 1
  • Tamoxifen or raloxifene for postmenopausal women: Both effective in reducing risk of invasive cancer 1, 3
  • Raloxifene is FDA-approved for reduction in risk of invasive breast cancer in postmenopausal women with LCIS 3

• Surgical Options:

  • Bilateral risk-reduction mastectomy may be considered in special circumstances:
    • Women with BRCA1/2 mutation 1
    • Women with strong family history of breast cancer 1
    • The procedure can reduce risk by 90-95% but is not recommended for most women with LCIS 1
  • If mastectomy is chosen, a bilateral procedure is required as risk is equal in both breasts 1
  • Women treated with bilateral mastectomy are appropriate candidates for breast reconstruction 1

Follow-up Recommendations

• Interval history and physical examinations every 6 to 12 months 1
• Annual diagnostic mammography for patients being followed with clinical observation 1
• Patients receiving tamoxifen or raloxifene therapy should be monitored according to breast cancer risk reduction guidelines 1

Special Considerations

• Pleomorphic LCIS may behave more aggressively than classic LCIS, but outcome data regarding treatment of this variant are lacking 1, 4
• LCIS is often multicentric (60-90%) and bilateral (20-45%) in nature 5, 6
• Despite current recommendations favoring observation, population-based studies show increasing rates of mastectomy for LCIS in the United States (50% increase from 2000 to 2009) 7

Common Pitfalls to Avoid

• Do not confuse LCIS with invasive lobular carcinoma, which requires different management 4
• Avoid unnecessary excision of biopsy sites to obtain clear margins for LCIS 5
• Do not recommend unilateral mastectomy, as risk is equal in both breasts 1
• Recognize that LCIS is a marker of increased risk rather than a true premalignant lesion requiring aggressive treatment 2, 5

Decision-Making Algorithm

1. Confirm diagnosis of pure LCIS through pathology review 1
2. Evaluate for additional risk factors (BRCA status, family history) 1
3. Discuss all management options with patient:
   • Observation with regular follow-up (preferred for most patients) 1
   • Chemoprevention with tamoxifen or raloxifene 1, 3
   • Bilateral risk-reduction mastectomy (for high-risk patients only) 1
4. Implement chosen strategy with appropriate monitoring protocol 1

The management of LCIS has evolved from routine mastectomy to a more conservative approach, recognizing its role as a risk marker rather than an obligate precursor to invasive disease 2, 5.