Lobular breast cancer starts in the milk-producing lobules and can spread through metastasis. The prognosis depends on factors such as cancer grade and stage and long-term care plans.

Lobular breast cancer is also called invasive lobular carcinoma (ILC). It’s the second most common type of breast cancer.

ILC affects about 10% of people with invasive breast cancer. Most people with breast cancer have invasive ductal carcinoma (IDC), which is cancer of the ducts (the structures that carry milk).

Follow-up appointments and tests can help your doctor detect a recurrence of cancer or any other complications.

Your outlook with ILC depends on the grade and stage of your cancer, as well as your long-term care plans.

The stage of cancer identifies the size and spread of the tumor, while the grade describes its appearance and how likely it is to spread. Healthcare professionals determine these by examining cancer cells under a microscope after a biopsy.

The grades range from 1 (slow-growing, least likely to spread) to 3 (growing and spreading quickly). Identifying the grade of your cancer will help doctors determine treatment options and predict your outlook.

This type of cancer is often hormone receptor-positive, usually estrogen-positive. This means the cancer cells need the hormone in order to grow. A medication that blocks the effects of estrogen can help prevent a recurrence of cancer and improve your outlook.

Lobular vs. ductal breast cancer prognosis

ILC tumors may spread aggressively and tend to be relatively large. In addition, people who receive an ILC diagnosis are an average of 3 years older than those who receive an IDC diagnosis. ILC is most often diagnosed at a more advanced stage.

Overall, long-term outcomes for people with ILC tend to be similar to the outcomes for people with other types of invasive breast cancer. However, some subgroups of people with ILC have worse outcomes than those with IDC, primarily related to the type of tumor they have and its treatment.

Survival rates for cancer are typically calculated in terms of how many people live at least 5 years after their diagnosis relative to people without cancer who are alive after the same time period. However, they can also be calculated for 10 years or longer.

Breast cancer survival rates

The average 5-year relative survival rate for breast cancers of all stages and grades is 91%, and the 10-year relative survival rate is 85%.

The stage of the cancer is important when considering survival rates. For instance, if the cancer is only in the breast, the 5-year survival rate is 99%. If the cancer has spread to the lymph nodes, the rate decreases to 85%.

ILC survival rates

According to a 2021 study, the survival rate for ILC tends to be higher in the first years after diagnosis and decreases within 10 to 15 years after diagnosis.

However, a 2024 study found that the overall 5-year survival rate for ILC was quite high, at 88.6%, and the 10-year survival rate was 73.6%.

Because there are many variables depending on the type and spread of your cancer, it’s best to talk with your doctor about what to expect.

If you’ve been treated for ILC, it’s especially important to schedule a physical exam and a mammogram every year after your treatment. The first one should take place 6 months after surgery or radiation therapy is complete.

You can learn more about breast cancer survival rates and find support from others who are living with breast cancer by downloading Healthline’s free app.

What are invasive lobular carcinoma’s symptoms?

Lobular breast cancer symptoms may include a thickening or hardening of your breast (which can feel different from a lump), swelling, skin texture changes, dimpling, an inverted nipple, and breast or nipple pain.

Where does lobular breast cancer spread?

Lobular carcinoma often spreads to lymph nodes, bones, and other organs such as the uterus, ovaries, stomach, brain, liver, and lungs.

What is the best treatment for lobular carcinoma?

ILC can be hard to diagnose because it spreads in a unique pattern that may not show up on imaging tests. However, it’s a slow-growing cancer, which gives doctors time to plan treatment.

Your options include lumpectomy or mastectomy, depending on the stage of cancer, as well as hormonal therapy and chemotherapy.

Radiation may be necessary after a lumpectomy. Your doctor will create a personalized care plan depending on your health and the latest technologies available.

What is the most aggressive form of breast cancer?

Non-ILC triple-negative breast cancer tends to be more aggressive than other breast cancer types. It accounts for only 10% to 15% of all breast cancers but is more likely to spread and to come back after treatment.

ILC can also be triple-negative, which means the cancer cells don’t have receptors for progesterone and estrogen.

Lobular breast cancer (ILC) is the second most common form of breast cancer. Most people with breast cancer have invasive ductal carcinoma (IDC), which affects the milk ducts.

ILC affects the lobules, which are responsible for producing milk. Like IDC, it can spread to other parts of your body. Your outlook with this type of cancer depends on factors such as the cancer’s grade and stage and your long-term treatment plans.