Which type of breast cancer is most likely to be bilateral: March 2011
**Core Concept**
Breast cancer can be categorized into various subtypes based on histological and molecular characteristics. The bilateral occurrence of breast cancer is often associated with a specific genetic predisposition.
**Why the Correct Answer is Right**
BRCA1 and BRCA2 mutations are the most well-known genetic risk factors for breast cancer, particularly in families with a history of bilateral breast cancer. Women with BRCA1 mutations are at a higher risk of developing triple-negative breast cancer, whereas those with BRCA2 mutations are at a higher risk of developing hormone receptor-positive breast cancer. The bilateral occurrence of breast cancer is more likely in individuals with a family history of breast cancer, particularly in first-degree relatives.
**Why Each Wrong Option is Incorrect**
**Option A:** Ductal carcinoma in situ (DCIS) is a type of non-invasive breast cancer, but it is not typically associated with bilateral occurrence.
**Option B:** Inflammatory breast cancer is a rare and aggressive subtype, but it is not specifically linked to bilateral occurrence.
**Option C:** Lobular carcinoma in situ (LCIS) is a condition that increases the risk of developing invasive breast cancer, but it is not typically bilateral.
**Clinical Pearl / High-Yield Fact**
Breast cancers in BRCA1 mutation carriers are more likely to be high-grade, triple-negative, and have a poorer prognosis. This highlights the importance of genetic counseling and risk assessment in patients with a family history of breast cancer.
**Correct Answer:** C. Lobular carcinoma in situ (LCIS) is most likely to be bilateral.