Ductal carcinoma in situ, or DCIS, is the earliest form of breast cancer and is highly treatable, according to the MayoClinic.com. DCIS is a small cancerous growth in a milk duct of the breast that is contained within the duct and has not spread to the surrounding breast tissue. It usually causes no symptoms and is picked up by a mammogram. DCIS is rarely life threatening and if standard treatments are used the cure rate is close to 100 percent, according to the College of American Pathologists. But if DCIS is not treated, about 30 percent of women who are diagnosed with it will develop invasive breast cancer within 10 years.
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Lumpectomy
About 70 percent of women with DCIS are good candidates for a breast sparing surgery called a lumpectomy because the cancer is confined to just one area of the breast, according to the College of American Pathologists. In a lumpectomy, only the cancerous area and an extra margin of healthy tissue is removed. This allows the patient to keep as much of her breast as possible and usually means the patient will not require breast reconstruction. Women who opt for a lumpectomy have a slightly higher risk of the cancer returning compared to those who have their breast completely removed, according to MayoClinic.com. But long-term survival rates for both kinds of surgery are very similar. In some cases, when the cancer has been caught at a very early stage, a lumpectomy alone may be enough to treat it. But most women who opt for lumpectomy will require additional treatment with either radiation or drugs.
Mastectomy
The other surgical option for DCIS is simple mastectomy in which the entire breast and occasionally some lymph nodes under the arm are removed, according to MayoClinic.com. Breast reconstruction surgery can be performed at the same time as the breast is removed or in a separate procedure done later. Mastectomy for DCIS is not as common as it once was now that research has shown that a lumpectomy plus radiation leads to equivalent long-term survival rates, according to MayoClinic.com. A mastectomy is recommended for women with a large area of DCIS or with multiple areas of DCIS because too much tissue needs to be removed for a lumpectomy to get it all and the results might be disfiguring. Some women don't want to undergo radiation therapy or can't because they're pregnant or have another medical condition. For these women,a lumpectomy is not a good option and a mastectomy may be necessary. Because DCIS is not an invasive cancer, the removal of lymph nodes is usually not required. But if there are indications during surgery that the cancer has spread outside the milk duct, the surgeon may remove some lymph nodes to check for the spread of cancer there.
Radiation
Radiation therapy is given after a lumpectomy for DCIS to minimize the chances that the cancer will grow back or that any remaining cancer cells will spread outside the milk duct, according to MayoClinic.com. Radiation therapy employs powerful X-rays to kill any remaining cancer cells, which are easy to target because they grow so much faster than healthy cells, which makes them more susceptible to death by radiation. It is usually not used after a mastectomy because removing the entire breast reduces the risk of recurrence, but in some cases in which doctors suspect that the cancer might be more aggressive, radiation may be recommended, according to the College of American Pathologists. After a lumpectomy, the entire breast is irradiated with an extra dose aimed at the area where the cancer was cut out, according to the American Cancer Society. Side effects include fatigue, swelling in the breast and skin burns. It can take six months to a year after treatment for the burns and swelling to clear up.
Estrogen Blockers
Some women with DCIS have a form of the cancer that grows in response to the female hormone estrogen. These women may be offered drugs like tamoxifen, which block estrogen to reduce the chance that the cancer will return or grow more dangerous, according to MayoClinic.com. Unlike radiation, these drugs do not kill the cancer cells; they simply remove a factor that can stimulate its growth in the future. This is usually only offered after a lumpectomy, or a lumpectomy plus radiation, because the removal of the whole breast in a mastectomy so effectively reduces the risk of recurrence. The drugs have to be taken for five years after surgery, which reduces the chances of the cancer coming back by about half, according to the American Cancer Society. Side effects include tiredness, hot flashes, vaginal dryness or discharge and mood swings. These drugs raise the risk of cancer developing in the uterus and of blood clots that can cause a heart attack or stroke.
References
- MayoClinic.com: Ductal Carcinoma in Situ (DCIS)
- College of American Pathologists: Breast Cancer Ductal Carcinoma in Situ
- American Cancer Society: Treatment of Stage 0 (Non-Invasive) Breast Cancer
- American Cancer Society: Breast Cancer Hormone Therapy
- American Cancer Society: Breast Cancer Radiation Therapy
