|
|
 |
|
|
|
Types of Cancer > Breast Cancer
|
|
| What Is Carcinoma in Situ of the Breast? |
|
|
|
|
The human breast produces a wide variety of cancer types. Breast malignancies can be invasive or non-invasive. There are two types of non-invasive breast carcinomas, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS).
Ductal carcinoma in situ is the more commonly diagnosed non-invasive carcinoma of the breast. It was a relatively uncommon diagnosis before the introduction of widespread screening mammography. The incidence of DCIS was less than 5000 cases in the mid 1980’s compared with more than 50,000 cases currently diagnosed annually in the United States. Approximately 90% of DCIS are diagnosed by screening mammography, and 20% of all breast malignancies diagnosed by screening mammography are DCIS.
As with invasive breast cancer, older patients, a strong family history, advanced age during the first full-term pregnancy, and certain benign breast conditions are associated with this diagnosis. Hormonal replacement therapy (HRT) is also related to DCIS development. DCIS represents the pre-invasive phase of invasive ductal carcinoma. If left untreated, DCIS will progress to invasive ductal carcinoma in the majority of patients. The latent interval between the diagnosis of DCIS and invasive cancer development is less than 10 years.
The primary treatment of DCIS is surgery. Most patients in the United States receive breast-conserving surgery (local resection of the tumor) followed by radiation therapy. Few patients are treated with mastectomy (complete resection of the breast with surrounding tissues). Post-surgical radiation treatment is usually not needed in patients treated with mastectomy.
Ductal carcinoma in situ has a high cure rate. The long-term survival rate following breast conservation surgery and radiotherapy or mastectomy is more than 96%.
Lobular carcinoma in situ usually does not form calcification in breast tissue, thus screening mammography is not effective when diagnosing LCIS. Strictly speaking, LCIS is not a precancerous disease. However, patients with LCIS are at high risk of developing invasive breast cancers. Therefore, LCIS is a significant risk factor for breast cancer, and patients with LCIS should be followed up carefully. In addition, preventative treatments, such as tamoxifen therapy or prophylactic mastectomy can be considered in particular patient populations.
Between 20 to 30% of patients with LCIS will eventually develop invasive breast cancer if prophylactic treatment has not been performed, and the latent period between the diagnosis of LCIS and invasive cancer is more than 15 years. Interestingly, patients with lobular carcinoma in situ have a higher risk of developing invasive ductal carcinoma than invasive lobular carcinoma, and subsequent cancers are divided equally between both breasts even if the LCIS is found in only one breast.
|
|
|
|
| Author: | Jiade Jay Lu, M.D.
Diplomate, American Board of Radiology (Radiation Oncology) |
|
|
|
| Publish Date: October 21, 2004 |
|
|
| Starting chemotherapy? Be ready! |
| Find out what you need to know:
Supporting your natural defenses; Understanding blood counts; And questions to ask your doctor. |
|
|
|
|
