Which type of breast cancer is associated with an increased risk of invasive carcinoma in both breasts?

Lobular carcinoma in situ (LCIS) serves as a marker of increased risk for the development of invasive breast cancer, specifically because it has a unique biological behavior. While LCIS itself is not considered a true precursor to invasive carcinoma, its presence indicates a significant increase in the risk for developing breast cancer in both breasts. Women's risk of developing invasive breast cancer is increased by approximately 20-30% within 15 years after diagnosis of LCIS, and this elevated risk applies to both breasts, underscoring the bilateral risk.

In contrast, other types of breast cancer, such as invasive lobular carcinoma and invasive ductal carcinoma, typically present with an established malignancy rather than a risk factor. Ductal carcinoma in situ (DCIS) is also a non-invasive condition but is more localized and typically has more favorable outcomes compared to LCIS concerning bilateral risk. Therefore, the distinctive association of lobular carcinoma in situ with increased risk for invasive carcinoma in both breasts makes it the correct answer.