Lobular breast cancer, also called invasive lobular carcinoma (ILC), occurs in the breast lobules. Lobules are the areas of the breast that produce milk. ILC is the second most common type of breast cancer.

ILC affects about 10 percent of people with invasive breast cancer. Most people with breast cancer have the disease in their ducts, which are the structures that carry milk. This type of cancer is called invasive ductal carcinoma (IDC).

The word “invasive” means that cancer has spread to other areas from the point of origin. In the case of ILC, it has spread to a particular breast lobule.

For some people, this means cancerous cells are present in other sections of breast tissue. For others, it means the disease has spread (metastasized) to other parts of the body.

Although people can be diagnosed with lobular breast cancer at any age, it’s most common in women aged 60 years and older. Research suggests that hormone replacement therapy after menopause may increase the risk of this type of cancer.

Like other cancers, ILC is staged on a 0 to 4 scale. Staging has to do with the size of the tumors, lymph node involvement, and whether tumors have spread to other areas of the body. Higher numbers represent more advanced stages.

The earlier you’re diagnosed with ILC and start treatment, the better your outlook. As with other types of cancer, early stages of ILC are likely to be treated more easily with fewer complications. This typically — but not always — leads to a complete recovery and low recurrence rates.

However, early diagnosis is a significant challenge with ILC compared with the much more common IDC. That’s because the growth and spread patterns of ILC are more difficult to detect on routine mammograms and breast exams.

Your outlook depends not only on the stage of cancer, but also on your long-term care plans. Follow-up appointments and tests can help your doctor detect a recurrence of cancer or any other complications that may arise after breast cancer treatment.

Schedule a physical exam and a mammogram every year. The first one should take place six months after a surgery or radiation therapy is complete.

Survival rates for cancer are typically calculated in terms of how many people live at least five years after their diagnosis. Although survival rates are similar between ILC and IDC, research has shown people with ILC have a slightly better outlook for both short- and long-term survival.

A 1997 study published in the British Journal of Cancer showed that people with ILC had less spread of cancer and higher 5- and 30-year survival rates than people with IDC.

In ILC, the 5-year survival rate was 78 percent, and the 30-year survival rate was 50 percent. In IDC, the 5-year rate was 63 percent, and the 30-year rate was 37 percent.

More recent studies published in Breast Cancer Research suggest 5-year disease-free survival rates have since improved. This 2004 study showed rates had risen for both types to about 85 percent for ILC and approximately 83 percent for IDC.

While the disparity between the two types of cancer is not as wide in more recent research, the outlook for ILC still appears to be brighter than that of IDC.

ILC can be more difficult to diagnose than other forms of breast cancer because it spreads in a unique pattern of branching. The good news is that it’s a relatively slow-growing cancer, which gives you time to form a treatment plan with your cancer team.

There are several treatment options that can help increase your chances of a full recovery.


Treatment varies depending on the stage of your cancer. Small tumors in the breast that have not yet spread may be removed in a lumpectomy. This procedure is a scaled down version of a full mastectomy. In a lumpectomy, only part of the breast tissue is removed.

In a mastectomy, an entire breast is removed with or without the underlying muscle and connective tissue.

Other therapies

Hormonal therapy, also called anti-estrogen therapy, or chemotherapy may be used to shrink tumors before surgery. You may need radiation after a lumpectomy to make sure all of the cancer cells have been destroyed.

Your doctor will help you form a care plan that’s personalized based on your health, using the most current technologies available.

A diagnosis of ILC can be challenging, especially since it’s harder to initially diagnose, as well as not being as well-studied as IDC. However, many people live long after their diagnosis.

Medical research and technology that was available five years ago may not always be as advanced as current treatment options. A diagnosis of ILC today may have a more positive outlook than it would have five or more years ago.

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