Understanding Lobular Breast Cancer: Insights, Diagnosis, and Treatment



Lobular breast cancer, also known as invasive lobular carcinoma (ILC), is a type of breast cancer that originates in the milk-producing lobules of the breast. Distinguished from the more common invasive ductal carcinoma (IDC), which begins in the milk ducts, ILC typically presents with a unique pattern of spread and growth. ILC is the second most common form of breast cancer and accounts for about 10% to 15% of all breast cancers.

Most commonly diagnosed in older women, although it can occur at any age, ILC is often challenging to detect due to its diffuse nature. The treatment and prognosis for lobular breast cancer generally align with other types of breast cancer, involving a combination of surgery, radiation, chemotherapy, and hormone therapy, depending on the individual case.

Continue reading to learn how lobular breast cancer is different from other forms of breast cancer, its connections with genetic mutations, and how ILC is diagnosed and treated.

How is lobular breast cancer different from other subtypes of breast cancer?

Invasive lobular carcinoma (ILC) is a type of breast cancer that is recognized as biologically distinct from the more common invasive ductal carcinoma (IDC).

ILC is distinct from other forms of breast cancer in several ways:

Cellular characteristics: ILC is characterized by the loss of the cell adhesion molecule E-cadherin, leading to discohesive cells that proliferate into single-file strands. This unique growth pattern contributes to the difficulty in detecting ILC using standard imaging techniques​​.

Hormone receptor status: ILC tumors are often estrogen receptor- (ER) positive, affecting treatment choices and responsiveness​​.

Metastatic patterns: Unlike ductal carcinomas that form distinct lumps, ILC grows in sheets throughout the breast tissue, making tumors more challenging to detect. It’s also more likely to be multifocal (occurring in multiple sites) and bilateral (occurring in both breasts).

What genetic and molecular factors are associated with lobular breast cancer?

ILC often exhibits specific genetic mutations and molecular features distinct from IDC. For example, mutations in the CDH1 gene are commonly associated with ILC, which can affect how cells adhere to each other.