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

Management of Typical Lobular Carcinoma In Situ (LCIS)

Observation with regular surveillance is the preferred management strategy for typical LCIS, as it is considered a marker of increased breast cancer risk rather than a true precursor lesion that requires aggressive intervention. 1

Understanding LCIS

Typical LCIS is not considered cancer but rather a risk marker that identifies women with an increased likelihood of developing invasive breast cancer in the future. Key characteristics include:

• Lifetime risk of developing invasive breast cancer ranges from 10-20% (approximately 0.5-1.0% annual risk) 2
• Risk is equal in both breasts, regardless of which breast contained the original LCIS 1
• Most subsequent invasive cancers occur more than 15 years after the initial LCIS diagnosis 2
• Excellent prognosis with appropriate monitoring 1

Management Algorithm

1. Surveillance (First-line approach)

• Regular clinical examinations every 6-12 months 1, 2
• Annual diagnostic mammography 1
• No need to excise biopsy sites of LCIS to obtain clear margins 2

2. Risk Reduction Options

Chemoprevention (Recommended adjunct to surveillance)

• Tamoxifen for premenopausal women 1, 3
  • Reduces risk of invasive breast cancer by approximately 46% 1, 3
  • Category 1 recommendation (highest level of evidence) 1
• Tamoxifen or raloxifene for postmenopausal women 1, 4
  • STAR trial showed raloxifene to be as effective as tamoxifen in postmenopausal women 1
  • Raloxifene is indicated specifically for reduction in risk of invasive breast cancer in postmenopausal women at high risk, including those with LCIS 4

Surgical Intervention (Limited role)

• Bilateral risk-reduction mastectomy is not recommended for most women with typical LCIS 1
• Should only be considered in special circumstances:
  • Women with BRCA1/2 mutations 1
  • Strong family history of breast cancer 1
  • Patient preference after thorough counseling about risks and benefits 1

Important Distinctions and Caveats

Pleomorphic LCIS vs. Typical LCIS

• Pleomorphic LCIS is a histologically aggressive variant with potentially greater risk for developing into invasive lobular carcinoma 1
• Management of pleomorphic LCIS may differ from typical LCIS, but outcome data are limited 1
• The recommendations above apply specifically to typical LCIS

Common Pitfalls to Avoid

1. Overtreatment: Treating LCIS as if it were DCIS (ductal carcinoma in situ). Unlike DCIS, which is considered a true precursor lesion, LCIS is primarily a risk marker 1, 2

2. Inadequate follow-up: Women with LCIS require consistent long-term surveillance due to the persistent elevated risk of developing breast cancer 1

3. Failure to discuss risk reduction options: All women with LCIS should be informed about chemoprevention options, which have demonstrated significant risk reduction 1, 3

4. Unnecessary surgical excision: There is no need to obtain clear margins when LCIS is found on biopsy 2

5. Unilateral focus: The risk for developing breast cancer after LCIS is equal in both breasts, so surveillance must be bilateral 1

The management of typical LCIS has evolved from more aggressive approaches (historical bilateral mastectomy) to the current standard of observation with consideration of chemoprevention, reflecting our improved understanding of LCIS as a risk marker rather than an obligate precursor to invasive cancer.