Invasive Ductal Breast Cancer (IDC)
Invasive ductal carcinoma (IDC), also called infiltrating ductal carcinoma, is the most common type of breast cancer. It constitutes about 80% of all diagnosed breast cancers.
The breast is an organ designed to manufacture and deliver milk to the infant. The majority of the breast is composed of fatty tissue. Milk glands lie within this fatty tissue and are connected to the nipple via a series of ducts.
Invasive means that the cancer which had originally started in the ducts of the breast (DCIS) has broken through the membrane of the ducts and invaded the surrounding tissue.
Once the cancer cells ahve broken through the ductal membrane, they can invade the lymph and blood systems, and spread further to other parts of the body. This is known as metastasis.
Invasive ductal breast cancer usually occurs in women who are over the age of 55 years. It is basically a postmenopausal condition. It can also occur in older men - that is, men who have crossed 50 years of age.
Symptoms of Invasive Ductal Carcinoma (IDC):
- No Symptoms: In early cases, invasive ductal breast cancer (IDC) can cause no symptoms of breast cancer at all. It may be suspected at a routine mammography or physical examination and then later confirmed by a biopsy.
- Breast Lump: In most cases of invasive ductal cancer, the first symptom is usually a lump in the breast. This lump may be anywhere in the breast but is more likely to be near the nipple or areola. Like most breast cancers, these are also non-tender, firm to hard lumps. In later cases, the lump may be fixed to the skin or underlying tissues and may feel irregular and lumpy.
- Nipple Discharge: Any nipple discharge other than milk should always be evaluated for breast cancer, especially ductal cancer. Some women may have a nipple discharge which may be yellowish, greenish or reddish. Reddish implies the presence of blood while greenish or yellowish may indicate the presence of infection.
- Dimpling of the Skin of the Breast: In some cases of invasive ductal breast cancer, especially later cases, there may be dimpling or irregularities of the skin. This is called 'peau de orange', meaning 'like the skin of an orange'. This change occurs when strands of tumor cells fix the skin at some places and pull it down towards the tumor causing the skin to dimple at those places.
- 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.
- Inversion of the Nipple : The nipple may be inverted or turn inwards when the tumor cells stretch between the nipple and the tumor deeper inside the breast and pull at the nipple.
- Lump under the Armpit: When the cancer cells spread to the lymph nodes under the armpit, hard Lumps may be felt in this region.
- Nipple Irritation, Itching:This symptom generally occurs when the invasive ductal cancer originates from Ductal Cancer in Situ (DCIS) of the breast.
Stages of Invasive Ductal breast cancer (IDC):
Like all other cancers, invasive ductal cancer is also staged according to the TNM method in which T stands for the size of the tumor, N stands for the lymph nodes involved and M stands for metastasis of the cancer cells to other tissues.