- Lobular breast cancer is a type of invasive breast cancer found in the tiny lobule sacs of the breast.
- It is less common than ductal breast cancer, accounting for only 10% of invasive breast cancers.
- Risks for developing lobular breast cancer including age, a history of lobular cancer in situ, and using hormone replacement therapy.
- Treatment options consist of both local and systemic therapies.
- Early detection is key to successfully treating lobular breast cancer.
Lobular breast cancer is a type of invasive breast cancer often referred to as invasive lobular carcinoma (ILC). Invasive breast cancer means the cancer cells have moved outside of the lobule of the breast. Lobules are clusters of tiny sacs in the breast that produce milk.
Lobular cancer in situ (LCIS) is not considered cancer but rather a collection of abnormal cells in the breast lobules. LCIS is typically found during a mammogram and is diagnosed with a breast biopsy. It can also be found during a biopsy to evaluate surrounding breast tissue.
Lobular breast cancer is a less common type of breast cancer than invasive ductal carcinoma. It only accounts for one out of every 10 cases of invasive breast cancer.
Twenty percent of women who are diagnosed with ILC also have cancer in the other breast too, making screening extremely important.
What Are the Risk Factors for Developing ILC?
Women diagnosed with ILC tend to be older than women diagnosed with ductal carcinoma (early 60s compared to mid-50s).
If a woman has used hormone therapy to manage postmenopausal symptoms, including estrogen and progesterone, they are at increased risk for developing lobular breast cancer later in life.
There are also inherited genetic cancer syndromes, including hereditary diffuse gastric cancer syndrome, that can increase a woman’s ILC risk. This is why it’s important to have genetic testing if a first-degree relative has been diagnosed with breast cancer, especially if they were young at the time, to determine if you have any of these genetic syndromes. These syndromes often increase a woman’s risk for developing cancer in their ovaries or gastric cancer.
A history of lobular carcinoma in situ (LCIS) is another risk factor for developing ILC. If a woman has a history of LCIS, they have an increased risk of developing lobular breast cancer in the future.
What Are the Symptoms of Lobular Breast Cancer?
You most likely won’t initially see symptoms of early lobular breast cancer, but breast changes can occur as the cancer grows. These changes include:
- Thickening (or toughening) in part of the breast
- Fullness or swelling (enlargement) in the breast
- Dimpling or thickening of the skin of the breast
- Nipple inversion that was not previously there
It’s important to note that lobular breast cancer is less likely to form a distinct lump often associated with identifying breast cancer.
This further reinforces the importance of screening methods beyond self-exams or clinician breast exams (including mammogram and breast MRI).
If you notice any of these symptoms, it’s important to see your healthcare provider so they can do a full medical exam and schedule testing.
How Do You Diagnose ILC?
When found in its early stages, ILC has a similar prognosis, or survival rate, as other breast cancers. The five-year survival rate for breast cancer found in early stages (localized and regional) is 86-99%
In addition to a breast exam performed by your healthcare provider, several tests can diagnose lobular breast cancer.
1. Mammogram and Ultrasound
An X-ray of the breast, or mammogram, is typically done along with an ultrasound of the breast to examine an area of concern. The ultrasound creates additional images of the breast tissue and is felt to be more accurate in detecting ILC than a mammogram alone.
3D mammograms have become the preferred mammogram thanks to the ability to find extremely small variations in breast tissue. 3D mammograms create a more detailed image than a traditional 2D mammogram.
2. Breast MRI and Biopsy
Magnetic resonance imaging (MRI) uses magnetic radio waves rather than radioactive waves and helps collect detailed images of the breast. Breast MRIs are often used to guide a biopsy of the area in concern.
Breast biopsies consist of taking a small sample of tissue by making a small incision and using a needle to collect samples. A biopsy is needed to make a definitive diagnosis of lobular breast cancer.
What Treatment Options Are Available?
Treatments for lobular breast cancer are divided into two categories: local and systemic.
1. Local Treatment
Local treatment for lobular breast cancer includes surgery and radiation. Potential surgical options consist of a lumpectomy (removing only the “lump” or tumor) and a mastectomy (removing the entire breast).
Lymph nodes are also typically removed during surgery to make sure the cancer has not spread to the surrounding tissue.
Radiation therapy uses targeted high-energy rays to kill any remaining breast cancer cells in the area. Women with lobular breast cancer typically have both surgery and radiation during their treatment. Radiation therapy can be done prior to surgery or after.
2. Systemic Treatment
Systemic treatment can include chemotherapy, hormone therapy, and/or HER2-targeted therapy. Not every woman diagnosed with ILC needs systemic treatment, but they are used quite often as part of treatment.
Chemotherapy is not always used, and the decision to use chemotherapy depends on a few factors. Namely, these are the size of the tumor when it was diagnosed and the presence of any genetic syndromes.
Chemotherapy is administered through a vein in your arm and is often given over a period of three to six months.
Lobular breast cancers tend to feed off hormones like estrogen and progesterone more than ductal breast cancers. When someone is diagnosed with breast cancer, they will have their breast tissues tested for these hormone receptors on the cancer cells to see if they will benefit from hormone therapy.
Hormone therapy is used to reduce estrogen. Because of this, it’s called anti-estrogen therapy.
Anti-estrogen drugs work in different ways. Some destroy estrogen receptors, some reduce how much estrogen your body makes, and some mimic estrogen and take its place in breast cancer cells. Other medications work by shutting down ovarian function.
HER2 is a protein found on the surface of some breast cancer cells, referred to as HER2 positive. When a cell has a protein on it, it acts like a little flag on the surface. This ‘flag’ serves as a way to identify the cell.
Thanks to advances in breast cancer research, there are now certain medications that can find this flag (protein) and destroy it along with the breast cancer cell it’s attached to.
Since it only kills cells with the HER2 protein, it is considered targeted therapy. These medications are typically given in addition to chemotherapy.
How Can I Prevent Lobular Breast Cancer?
It’s impossible to eliminate all risks for developing ILC, but some lifestyle changes can help reduce your overall risk of developing breast cancer. These include:
- If you feel you need to take hormonal therapy for menopause or postmenopausal symptoms, use the lowest dose for the shortest amount of time possible.
- Drink no more than one glass of alcohol per day (if any at all).
- Exercise for 30 minutes most days.
- Maintain a healthy weight.
If you have any risk factors for developing lobular breast cancer, more frequent screening and follow-up can help detect it in its early stages.
Early Screening May Improve ILC Outcomes
As with all cancers, early detection is key to improving treatment options so you can move on to enjoying life.
Since lobular breast cancer doesn’t create the classic “lump” many women are taught to look for, routine screening can identify cancer sooner, while it’s still in the early stages.