What is the prognosis for a patient diagnosed with atypical lobular hyperplasia (ALH) of the breast?

Prognosis for Atypical Lobular Hyperplasia of Breast

Atypical lobular hyperplasia (ALH) significantly increases breast cancer risk, with a lifetime risk approximately 4-5 times that of the general population, equating to a continuous risk of about 0.5% to 1.0% per year. 1

Risk Assessment

ALH is classified as a proliferative lesion with atypia that serves as both a risk factor and a nonobligate precursor to invasive breast cancer:

• The risk affects both breasts, though there is a 2:1 ratio of ipsilateral to contralateral breast cancer development 2
• The ipsilateral predominance is more marked in the first 5 years after diagnosis, consistent with a precursor phenotype 2
• Long-term follow-up studies show the risk persists for decades 1

Cancer Characteristics When Developed

When women with ALH develop breast cancer, the characteristics typically include:

• Predominantly invasive ductal carcinomas (not lobular as might be expected)
• Approximately 69% are of moderate or high grade
• About 25% are node positive at diagnosis 2
• Both ductal carcinoma in situ (DCIS) and invasive cancers can develop 2

Surveillance Recommendations

Due to the increased risk, close surveillance is essential:

• Regular clinical examinations every 6-12 months
• Annual diagnostic mammography
• Consider supplemental screening with breast MRI, particularly for women with dense breasts 1
• Surveillance must be bilateral since risk affects both breasts 1

Risk Reduction Options

Several risk reduction strategies are available:

Chemoprevention

• All women with ALH should be informed about chemoprevention options 1
• For premenopausal women: Tamoxifen for 5 years reduces invasive breast cancer risk by approximately 46% (hazard ratio 0.54; 95% CI 0.27-1.02) 1
• For postmenopausal women: Options include tamoxifen, raloxifene, exemestane, or anastrozole 3, 1
• Anastrozole (1 mg/day orally for 5 years) is particularly effective for postmenopausal women with atypical hyperplasia 3

Surgical Options

• Surgical excision is recommended when ALH involves more than 4 terminal ductal units or when there is radiologic-pathologic discordance 1
• Bilateral risk-reduction mastectomy may be considered in special circumstances (BRCA mutations, strong family history) but is generally not recommended for ALH alone 1

Age Considerations

• For women ages 40-60 years at diagnosis, chemoprevention results in the greatest quality-adjusted life expectancy
• For women diagnosed at age 65 and older, surveillance alone may be the preferred strategy for optimizing quality-adjusted life expectancy 1

Common Pitfalls to Avoid

1. Overtreatment: Limited ALH (≤3 foci) with radiologic-pathologic concordance can be safely observed rather than surgically excised 1, 4

2. Inadequate follow-up: Since risk persists long-term, consistent surveillance for decades is necessary 1

3. Failure to discuss risk reduction options: All women with ALH should be informed about chemoprevention options 1

4. Unnecessary surgical excision: When minimal ALH is an incidental finding on core biopsy with radiologic concordance, excision may not be necessary 4

By understanding ALH as both a risk factor and potential precursor lesion, appropriate management can significantly reduce the likelihood of developing invasive breast cancer while avoiding unnecessary interventions.