Introduction:
Invasive lobular carcinoma (ILC) denotes cancer that originates in the cells present in the lobules and has infiltrated into the surrounding breast tissue. ILC invades the lobules, the glands that produce milk when breastfeeding. Women over 55 are more prone to be diagnosed with invasive lobular carcinoma. The diagnosis of this breast cancer is also difficult because, like other tumors, ILC does not grow as a mass or clumps, but it forms a line, so physical examination and mammography do not reveal its presence.
What Is Invasive Lobular Carcinoma?
Invasive lobular carcinoma is a kind of breast carcinoma that originates in the milk-producing glands called the lobules of the breast. It is the second most common invasive breast carcinoma in the United States, following invasive ductal carcinoma. Invasive carcinomas are not constrained inside the lobules. They spread out of the lobule to invade the lymph nodes and other body parts. This feature differentiates it from lobular carcinoma in situ (LCIS), where the cancer cells develop inside the lobules.
What Are the Microscopic Features of Invasive Lobular Carcinoma?
On microscopic examination, invasive lobular carcinoma consists of a uniform number of small to medium-sized tumor cells that are discohesive (loosely connected to each other). Typically in ILC cases, the tumor cells grow in single files or slender strands or a concentric fashion, surrounding the lobules or ducts. The stroma is fibrotic and has foci of perivenous and periductal elastosis. Lymphocytic infiltrates can also be noted.
In most cases of invasive lobular carcinoma, E-Cadherin immunoreactivity is absent. However, in 16 % of cases, abnormal features of E-Cadherin can be seen. E-Cadherin is a transmembrane protein that is necessary for cell-to-cell adhesion. The absence of E-Cadherin in ILC is due to the loss of a tumor suppressor gene CDH1 expression on chromosome 16q. So, the ILCs do not contain E-Cadherin and are discohesive, with only single cells penetrating through the breast parenchyma.
What Are the Symptoms of Invasive Lobular Carcinoma?
In many cases, invasive lobular carcinoma causes no symptoms, and one cannot notice any firm lumps. It is often found after noticing a suspicious area, by the doctor, on a screening mammogram. While in other cases, a thick or swollen area in the breast can be palpated. Other unusual changes seen in the breast of women with invasive lobular carcinoma are
-
Swelling of all or part of the breast.
-
Skin irritation.
-
Change in texture of the breast skin, sometimes looking like an orange peel.
-
Breast or nipple pain.
-
Unusual nipple discharge.
-
A nipple that turns inward.
-
Thickening, redness, or scaliness of the skin of the breast or nipple.
-
Swelling or lump in the underarm area.
What Is the Diagnosis of Invasive Lobular Carcinoma?
Invasive lobular cancer is difficult to detect on a mammogram, as it grows in line rather than a lump or mass like other tumors. Depending upon the symptoms and other areas of concern on a mammogram doctor may suggest additional screening tests such as:
-
Ultrasound.
-
MRI (magnetic resonance imaging).
-
Breast needle biopsy.
-
PET (positron emission tomography) scan.
What Is the Treatment for Invasive Lobular Carcinoma?
Treatment for invasive lobular carcinoma depends on numerous factors, including the cancer stage, the aggressiveness of cancer, the patient's health, and their treatment preferences. There are many treatment options like
1. Surgery - Depending on the location and size of the ILC tumor, treatment can include
-
Lumpectomy - In this procedure, the tumor and the normal tissue margin surrounding the tumor are removed to ensure there are negative cancer cells. If any sign of positive margins is detected, additional surgery is needed to remove all the cancer cells till the surgeon detects clean margins.
-
Mastectomy - In this procedure complete breast involving the cancer is removed, including the ducts, lobules, fatty tissue, nipple, areola, and skin. In some cases, the skin covering the breast and the nipple is left behind based on the specific situation.
-
Lymph Node Dissection - This is done to check the spread of cancer to the adjacent lymph nodes. Adjacent lymph nodes that receive lymph drainage from cancer are identified and tested. If the cancer is negative, the chance of finding cancer in the remaining nodes is nil, and removal of the node is not required. If cancer is found, it is necessary to remove additional lymph nodes from the armpit, called the axillary lymph node dissection.
2. Hormonal Therapy (Endocrine Therapy) - If ILC contains hormone receptors for estrogen, progesterone, or both, the doctor will mostly suggest hormonal therapy, also called endocrine therapy or anti-estrogen therapy. Hormonal therapy acts by blocking the action of estrogen on the cancer cells or reducing the amount of hormone in the body. It is used to decrease the chance of cancer returning. Hormone therapy can be provided before or after surgery or along with other treatments. Hormone therapy is also helpful in shrinking and controlling breast cancer.
3. Radiation Therapy - In radiation therapy, high-powered energy, like protons and X-rays, are used to destroy cancer cells. It is often recommended after a lumpectomy. And in some cases, like cancer being too big or cancer involving the lymph nodes, it is recommended after a mastectomy.
4. Chemotherapy - In chemotherapy, drugs are used to kill cancer cells. Chemotherapy can be introduced in various forms orally, in pill form, intravenously (IV), or both ways. It is often recommended after surgery to destroy any remaining cancer cells. The commonly used chemotherapy drugs are Capecitabine, Doxorubicin, Fluorouraci, Cyclophosphamide, Paclitaxel, Epirubicin, Methotrexate, Docetaxel, and Ixabepilone.
5. Targeted Therapy - Targeted cancer therapies target specific cancer cell characteristics. Some targeted therapies are antibodies that act like natural antibodies produced by the immune systems called immune targeted therapies.
Side Effects of Treatment - Patients go through many side effects following cancer therapy; for example, after radiation therapy, breast swelling and pain, changes in breast tissues, swelling and pain in the arm and breast, problems with breastfeeding, and fluid accumulation in the breast can be experienced. Chemotherapy can cause hair loss, loss of appetite, nausea and vomiting, weight loss, menstrual changes, fatigue, fertility problems, opportunistic infections, etc.
Conclusion:
Invasive lobular carcinoma is a breast cancer affecting the milk ducts of the breast. It is a slow-growing and invasive type of carcinoma. The treatment depends on the cancer staging and other factors like age, health issues, etc. In general, early-stage ILC has an excellent prognosis compared to the advanced stage. Modern medical technologies have made the treatment more effective than in the past.
