Intraductal carcinoma, also known as ductal carcinoma is a non-invasive or pre-invasive breast cancer. It is characterized by the presence of abnormal cells inside a milk duct in the breast. It cannot invade through the walls of the ducts or spread to the other tissues. It is the earliest form of breast cancer. It is not a life-threatening condition, but requires treatment as it may become invasive if left untreated.
The causes of intraductal carcinoma are unknown. It may occur due to genetic mutations in the DNA of breast duct cells. Factors such as increasing age, hyperplasia, familial history of breast cancer, first pregnancy after age 30, use of contraceptive pills, and obesity can increase the risk of developing intraductal carcinoma.
Intraductal carcinoma does not show symptoms. Sometimes, a nipple discharge or lump may be felt in the breast. These are identified as small clusters in mammograms.
Intraductal carcinoma is diagnosed by mammogram. It appears as microcalcifications that are in irregular shape or size. Ultrasound and breast biopsies are also required to identify whether it is in situ or invasive. The breast tissue will be collected in different ways for biopsy. It includes:
Core Needle Biopsy: A hollow needle which is guided by ultrasound is used to remove tissue samples from the suspected area.
Stereotactic Biopsy: Mammogram images are used to take samples from the suspected area of the breast by a hollow needle.
Surgical Biopsy (wide local excision or lumpectomy): It involves the excision of a part of the breast tissue.
The treatment for Intraductal carcinoma involves the surgical removal of the affected breast part. The surgeries include breast-conserving surgery (lumpectomy) or breast-removing surgery (mastectomy).
Lumpectomy: It is the removal of the affected area and a margin of healthy tissue that surrounds it. This procedure conserves the healthy breast tissue and eliminates the need for breast reconstruction. It is followed by radiation therapy.
Mastectomy: In this procedure, the breast tissue along with skin, areola and nipple are removed. Sometimes the lymph nodes are also removed. Breast reconstruction is required after mastectomy. Mastectomy is recommended in cases if there is a large Intraductal carcinoma or more than one carcinoma.
Radiation therapy: High-energy beams, such as X-rays are used to destroy abnormal cells. Radiation therapy after lumpectomy reduces the recurrence of intraductal carcinoma or invasive Intraductal carcinoma. External beam radiation is most commonly used to treat intraductal carcinoma.
Adjuvant Therapy: The drug tamoxifen blocks the action of estrogen and reduces the risk of developing invasive breast cancer. Tamoxifen is effective against cancers that grow in response to hormones. It decreases the chances of recurrence of intraductal carcinoma.