Lobular breast cancer, also called invasive lobular carcinoma (ILC), occurs in the breast lobes or 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 ages 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.

ILC usually doesn’t form a lump, but spreads in single-file lines through the fatty tissue of the breast. They may be more likely to have multiple origins than other cancers and have a tendency to metastasize to bone.

One study demonstrates that the overall long-term outcome for people diagnosed with ILC may be similar or worse than for those diagnosed with other types of invasive breast cancer.

There are some positive points to consider. Most of these types of cancers are hormone receptor positive, usually estrogen (ER) positive, which means they grow in response to the hormone. Medication to block the effects of estrogen can help prevent a return of disease and improve prognosis.

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. The average five-year survival rate for breast cancer is 90 percent and the 10 year survival rate is 83 percent.

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

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

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.

Surgery

Treatment varies depending on the stage of your cancer. Small tumors in the breast that haven’t 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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