Invasive ductal carcinoma (IDC), sometimes called infiltrating ductal carcinoma, is the most common type of breast cancer. About 80% of all breast cancers are invasive ductal carcinomas.
According to the American Cancer Society, more than 180,000 women in the United States are diagnosed with invasive breast cancer each year. Most of them suffer from invasive ductal carcinoma.
Although invasive ductal carcinoma can occur in women at any age, it is more likely to develop this disease when women get older. According to the American Cancer Society, about two-thirds of women are 55 or older when they are diagnosed with an invasive breast cancer. Invasive ductal carcinoma occurs in men, too.
The nature of this disease can be described if we take each word separately.
Invasive means that the cancer has “invaded” or affected the surrounding breast tissues, and cancer cells can travel to others parts of the body.
Ductal means that the cancer started in the milk ducts, which are canals that carry milk from the milk-producing lobules to the nipple.
Carcinoma is a malignant tumor that starts in the skin or other tissues that cover internal organs — such as breast tissue. The synonym is cancer.
Thus, “invasive ductal carcinoma” is a breast cancer that has broken through the wall of the milk duct and begun to invade the tissues of the breast. Over time, invasive ductal carcinoma can spread to the lymph nodes and possibly to other areas of the body.
Signs and Symptoms of IDC
This type of breast cancer may not cause any signs or symptoms for some period of time. Pain or other discomfort in the breast is not common for invasive ductal carcinoma, but in some cases it takes place.
Typically, women themselves notice a thickening of the breast or another warning sign of breast cancer. Abnormal formations are detected by a screening mammogram (X-ray of the breast) or ultrasound.
As cancer cells spread to the axillary lymph nodes, a swelling in the underarm area appears. Later on, with the development of metastases, the person may experience a variety of signs and symptoms: fatigue and exhaustion, pain in the limbs and back (with bone metastases), ascites is an accumulation of fluid in the abdominal cavity (with liver metastases). Brain metastases usually lead to headache, epileptic seizures and other neurological symptoms.
According to the American Cancer Society, any of the following unusual changes in the breast can be a first sign of breast cancer, including invasive ductal carcinoma:
- swelling of all or part of the breast
- skin irritation or dimpling
- breast pain
- nipple pain or the nipple turning inward
- redness, scaliness, or thickening of the nipple or breast skin
- a nipple discharge other than breast milk
- a lump in the underarm area
Subtypes of invasive ductal carcinoma
There are four subtypes of invasive ductal carcinoma that are less common.
Medullary Ductal Carcinoma is rare and only three to five percent of breast cancers are diagnosed as medullary ductal carcinoma. The tumor usually shows up on a mammogram and it does not always feel like a lump; rather it can feel like a spongy change of breast tissue.
Mucinous Ductal Carcinoma occurs when cancer cells within the breast produce mucous, which also contains breast cancer cells, and the cells and mucous combine to form a tumor. Pure mucinous ductal carcinoma carries a better prognosis than more common types of IDCs.
Papillary Ductal Carcinoma looks like tiny fingers under the microscope. It is only in rare cases that this kind of cancer becomes invasive. Common among women age 50 and older, this kind of cancer is treated like DCIS, despite being an invasive cancer.
Tubular Ductal Carcinoma is a rare diagnosis of IDC, making up only two percent of diagnoses of breast cancer. Tubular ductal carcinoma is more common in women older than 50 and are usually small, estrogen-receptor positive cancers, which means they respond to hormones. The name comes from how the cancer looks under the microscope; like hundreds of tiny tubes.
Mammography and/or ultrasound are the first step in diagnosing malignant tumors of the breast. They are available, easy to carry out and take a very small amount of time.
After finding some signs of breast cancer biopsy of the breast is carried out. Tissue samples are sent for histological examination and immunohistochemistry (IHC). Immunohistochemical examination allows determining HER2 status of breast cancer and hormonal status of the tumor.
Breast cancer cannot be diagnosed without a biopsy. It is important to mention the treatment of breast cancer is never started in order to avoid mistakes.
If the results of biopsy are confirmed the diagnosis, in order to detect metastases the patient should take PET-CT.
The treatment of IDC depends on the stage, HER2 status and hormonal status of breast cancer.
Stages I, II and, in some case, III are treated with surgery – lumpectomy or mastectomy.
Today, a mastectomy (complete removal of the affected area) is less common than a lumpectomy (breast-conserving surgery, where only the tumor and the axillary lymph nodes are removed). In most cases, we talk about survival rate a mastectomy has no advantages over lumpectomy. Radiation therapy is used after lumpectomy in order to prevent tumor recurrence.
If invasive ductal adenocarcinoma of the breast is more than 1 cm and / or cancer cells were found in the axillary lymph nodes during surgery, chemotherapy is necessary after surgery.
Stage IV breast cancer requires chemotherapy. HER2 positive breast cancer requires a combination of chemotherapy and Herceptin.
Invasive ductal carcinoma prognosis. Women with invasive breast cancer have more promise for a good outcome than ever before. Talk to your doctor to determine the best course of treatment for your situation.