Invasive Lobular Breast Cancer (ILC)
Invasive Lobular Carcinoma (ILC), also called Infiltrating Lobular Cancer, make up about 10% of all breast cancers diagnosed. After Ductal Breast Cancer, it is the second most common breast cancer. Invasive means that the cancer which had originally started in the lobules of the breast has broken through the basement membrane of the lobules and invaded the surrounding tissue.
Invasive Lobular Breast Cancer (ILC) can occur at any age but is most common in women between 45-55 years. It is basically a perimenopausal condition. It can also occur in men of the same age, but is quite rare. Male breast cancers are usually ductal breast cancers.
It is common for lobular breast cancer to be diagnosed in both the breasts at the same time. If the condition occurs in only one breast, there is a high risk of it developing in the other breast in time.
Invading cells of ILC tend to break out of the main tumor in single file ('indian style') and spread through the breast in a web like pattern. They do not cause much response from the healthy cells - nether an inflammatory nor a scarring response as is seen in IDC. So a discrete mass or lump is not felt unless the tumor is quite large.
Some research has suggested that the use of hormone replacement therapy during and after menopause can increase the risk of ILC.
Symptoms of Invasive Lobular Carcinoma (ILC):
- No Symptoms: In early cases, Invasive lobular breast cancer can cause no symptoms of breast cancer at all. It may be suspected at a routine mammography or physical examination and the confirmed by a biopsy.
- No Breast Lump: Unlike most other breast cancers, invasive lobular cancer can occur without the presence of any lumps at all. This is because, it tends to form long, skinny “fingers,” of cancer cells which are much less irritating to the surrounding healthy tissue. These cause less inflammatory reaction in the tissues and so the chances of forming a lump is less.
- Dimpling of the Skin of the Breast: In some cases of invasive lobular breast cancer, the first symptom may be dimpling or irregularities of the skin of the breast. This can occur due to strands of tumor cells pulling on the skin to form dimples.
- Thickening in the Breast : The layers of cancer cells in lobular invasive cancer can cause thickening in the affected parts of the breast. On palpation, there will appear to be a change in the general texture of the breast with no definite lump felt. This makes lobular invasive cancer very difficult to diagnose on physical examination. Most invasive ductal cancer are first diagnosed when they form a lump of about 2 cm, but invasive lobular cancer can be about 5 cam in size before a diagnosis can be made.
- Inversion of the Nipple : The nipple may be inverted or retracted inwards when the tumor cells stretch between the nipple and the tumor deeper inside the breast and pull at the nipple.
- Nipple Discharge: Nipple discharge can occur in later cases when there is concurrent infection. The discharge may be yellowish, greenish or reddish. Reddish implies the presence of blood while greenish or yellowish may indicate the presence of infection.
- Pain: Pain is very uncommon. But in the presence of infection of the lump or when the lump presses on sensitive tissues like the nerves, there may be some amount of pain.
- Lump under the Armpit: When the cancer cells spread to the lymph nodes under the armpit, hard lumps may be felt in this region.
Stages of Invasive Lobular breast cancer (IDC):
Like all other cancers, invasive lobular cancer is also staged according to the TNM method in which T stands for the size of teh tumor, N stands for the lymph nodes involved and M stands for Metastasis of cancer cells.