Invasive lobular carcinoma, also called infiltrating lobular carcinoma, refers to cancer that affects the milk-producing glands called lobules. Invasive means it has spread to the surrounding breast tissues. It can spread to the surrounding tissue, lymph nodes, and even other organs over time if not promptly treated.

It is the second most common cancer after invasive ductal carcinoma. American Cancer Society estimates that almost 10% of all breast cancers are invasive lobular carcinomas (ILC). Almost two-thirds of the cases are seen in women who are 55 and older. Studies also suggest that hormone replacement therapy increases the risk of ILC.

Signs and Symptoms of Invasive Lobular Carcinoma

Invasive Lobular carcinoma or ILC does not initially show symptoms. This is because the cancer spreads to the surrounding connective tissue in a line formation rather than forming lumps. It is hard to pick up in a mammogram, although some abnormalities may show up. The most visible symptoms are fullness or swelling of the breast, nipple turning inward, or a change in the skin’s texture.

Breast pain, nipple pain, redness or scaliness of the nipple or breast skin, a lump in the underarm area, discharge from the nipple are signs to look out for in the case of ILC.

Diagnosis of Invasive Lobular Carcinoma

The tests which are used to diagnose ILC can include:

Physical exam: The signs of thickening or lumps may be picked up during a physical examination by your doctor. The breast area, collarbone, and underarm area will be examined for abnormalities.

Mammogram: ILC is usually hard to pick up in a mammogram due to the lack of lump formation. Abnormalities may show up in the mammogram, which will be further investigated.

Ultrasound and MRI: Imaging techniques like Ultrasound and MRI are also used in addition to mammography to determine or gather more information about ILC.

Biopsy: A biopsy is a procedure done to take a sample of the suspicious tissue, which is then studied by a pathologist to diagnose cancer. The biopsy may be of different types depending on the degree of invasiveness of the procedure. The less invasive procedures are fine needle aspiration biopsy and core needle biopsy. These procedures leave little to no scar. It may also be done with the help of ultrasound imaging to guide the needle to the site. This technique is called stereotactic needle biopsy.

The more invasive biopsies include incisional biopsy and excisional biopsy, where a small piece of the tissue or the entire lump is removed, respectively.

Staging of Invasive Lobular Carcinoma

Tests are done to determine the stage of ILC, i.e., the degree to which the cancer has spread from the site of origin. The stage of the carcinoma is determined based on the following –

  • the size of the tumor
  • how far it has spread to the lymph nodes
  • whether the cancer has spread to any other parts of the body

ILC is scaled from stage I, the earliest stage, to stage IV, which is the most advanced stage. Imaging techniques like PET scan and CT scan are used to determine these factors.

What tests can you expect to determine staging?

The initial tests will usually comprise a physical exam, imaging studies, blood tests including alkaline phosphatase (ALP), and liver function tests. The doctor may use these tests and a description of your symptoms to determine if ILC has spread. You may also need an X-Ray of the chest to check your lungs. Based on these results, your doctor may order further tests if needed, which may include a bone scan, a CT scan, ultrasound and MRI of certain body areas.

Tests for more information and treatment for ILC

Additional tests may be done on the tissue removed during biopsy or surgery to understand the tumor more and to determine the most suitable treatment. These tests generally can include one or more of the following.

Grading – The abnormality of the cancerous cells is compared to that of normal cells to determine the grade of cancer on a scale of 1-3. Grade 1 cells in ILC somewhat resemble normal cells, grow slowly and are less likely to spread than grade 3 cells which are abnormal, fast-growing and more likely to spread.

Surgical margins: A small amount of tissue that is immediately near the cancerous tissue is surgically removed. This margin is then studied for any traces of cancer cells to determine whether further surgery is needed.

Hormone receptor assay: This is a tissue test to determine whether the cancer has receptors for the hormones – progesterone and estrogen. Your doctor will recommend hormonal therapies if the test results are positive.

HER2-receptor status: This test determines whether the cancer cells produce too much of the protein human epidermal growth factor receptor 2. Too much of the protein indicate that the cancer cells may grow rapidly. Depending on the test results, your doctor may put you on medication to block the receptors to slow down or stop the growth of the cancer.

Treatment for Invasive Lobular Carcinoma

Invasive Lobular Carcinoma treatments fall into two categories – Local treatments and Systemic Treatments.

1 Local treatments

Local treatments include surgery and radiation to the tumor and surrounding areas. This may include lymph nodes and chest area. In most cases, surgery is the first line of treatment to remove the cancer and determine if it has spread to the lymph nodes.

Surgery may include

  • Lumpectomy – Only the lump or the tumor and some of the surrounding tissue are removed.
  • Mastectomy – Partial, where only the portion of the breast containing the tumor is removed. Total, where the breast tissue is removed totally. Modified radical mastectomy, where the breast tissue, some of the lymph nodes, and lining of chest wall muscle are removed.

Radiation may include

  • External beam radiation – Radiation is given to the entire area after the surgery.
  • Partial-breast irradiation – Highly localized radiation beam or placement of radioactive pellets at the site of the tumor. This treatment is not widely available as it is still under investigation.

2 Systemic treatments

Chemotherapy – through IV infusion or oral medicine. Your doctor will evaluate whether chemotherapy is ideal for you depending on your other health conditions and the staging and grading of cancer.

Hormonal Therapy – is used to lower the amount or block estrogen. This therapy may include selective estrogen receptor modulators, aromatase inhibitors and estrogen receptor downregulators. Your doctor will determine the best therapy suited to your condition.

Targeted therapies – target specific characteristics of cancer cells to halt their growth and prevent them from spreading.

Immunotherapy – This therapy uses the body’s immune system to attack and destroy the cancer cells.

Follow up care for ILC

Follow-up care for ILC depends on the kind of treatment you received. It generally includes a physical examination, mammogram, MRI, and regular monitoring of bone health over regular intervals. Additional tests may be done according to your individual need, as prescribed by the doctor. It is essential to follow what your doctor recommends to ensure that you get the maximum benefit and safety out of the treatment.

Invasive lobular carcinoma, if treated promptly, can ensure the quality of life of the person. The breakthroughs in treatment show promising results and the chance at a normal life. With timely intervention, ILC can be managed, treated and halted.