Introduction:
Ductal carcinoma in situ is a non-invasive type of cancer. It does not spread to adjacent lymph nodes. So during treatment, only the tumor cells and the margin must be surgically removed rather than all the lymph nodes. It is also known as intraductal carcinoma because cancer can only be seen in the cells of the ducts, it cannot spread to other parts of the body.
What Is Ductal Carcinoma In Situ?
Ductal carcinoma in situ (DCIS) has abnormal breast milk duct cells. Ductal carcinoma in situ is the initial form of breast cancer. It is non-invasive, does not spread outside the milk duct, and is usually diagnosed during a mammogram. Ductal carcinoma in situ usually does not show signs and symptoms. However, a lump in the breast and bloody discharge from the nipple are some of the symptoms usually noticed.
How Is Ductal Carcinoma In Situ Classified?
The tissues taken during the biopsy are viewed under a microscope to grade ductal carcinoma in situ.
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Low-Grade or Grade 1 Ductal Carcinoma In Situ - The cells in this grade of ductal carcinoma in situ are only slightly different from the normal healthy breast cells. The growth rate of the tumor is slow. The chance of cancer recurrence after treatment is less likely in low-grade ductal carcinoma in situ than in moderate or high-grade.
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Moderate Grade or Grade 2 Ductal Carcinoma In Situ - The cells in this grade look different from the healthy breast cells. The tumor cells have a higher growth rate. The tumor recurrence rate is higher than low grade but lower than high-grade tumors. This stage is also called intermediate grade.
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High-Grade or Grade 3 Ductal Carcinoma In Situ - The cells look completely different from normal healthy breast cells, and the growth rate of tumors is also very fast. The recurrence rate of this grade ductal carcinoma in situ is also very high.
How Can We Diagnose Ductal Carcinoma In Situ?
The diagnostic aid which is used to confirm ductal carcinoma in situ are:
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Mammography - This method uses low-energy X-ray radiation to visualize the breast, which can be used to detect cancers in the breast early.
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Breast Biopsy - When a suspicious breast lump is found, a biopsy is indicated in which small breast tissue is taken and examined in the laboratory to find any abnormal growth in the cells.
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Breast MRI - MRI (magnetic resonance imaging) uses strong magnetic fields and radio waves to create an image of the breast.
What Are the Treatments for Ductal Carcinoma In Situ?
The treatment options for ductal carcinoma in situ include surgical tumor removal, radiation therapy, and hormone therapy. Depending upon the grade of the carcinoma, treatment is decided. In severe cases, surgery, along with radiation and hormonal therapy, is advised.
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Surgery - In most cases, the tumor is removed to prevent recurrence. It can be a lumpectomy (breast-conserving surgery) or mastectomy (breast removal surgery).
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Lumpectomy - In this method, the area of ductal carcinoma in situ and healthy tissue around it is surgically removed. Breast reconstruction is unnecessary because most of the healthy breast tissues are left behind. There is a chance of recurrence of cancer in people who undergo lumpectomy. Most people with ductal carcinoma in situ are advised of lumpectomy.
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Mastectomy - Removal of all of the breast tissue is called mastectomy. After mastectomy, to rebuild or reshape the missing breast tissue, reconstruction procedures are performed. Mastectomy is considered when there is a large region of ductal carcinoma in situ or multifocal ductal carcinoma in situ.
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Radiation Therapy - Use high-energy beams like X-rays to destroy abnormal cells and decrease tumor growth by damaging DNA (deoxyribonucleic acid). After the lumpectomy, radiation therapy is done along with the surgery to prevent its recurrence. Patients with high-grade malignancy and large tumors are advised to receive radiation therapy after surgical removal of the tumor. Radiation therapy can be of two types, external beam radiation therapy (radiation comes from a machine outside, aiming at cancer to kill) and internal radiation therapy (or brachytherapy is when a source of radiation is inside the body by using capsules and seeds that contains radiation, are put inside the body).
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Hormone Therapy - Hormone therapies are used when cancer grows in response to hormones. It will block the hormones helping in the growth of cancerous cells. This therapy is advised along with surgery or radiation to prevent cancer recurrence.
What Is the Boost Dose After Radiation Therapy in Ductal Carcinoma In Situ?
A radiation boost is an extra booster dose targeted to the area where the cancer is situated. For example, in moderate to high-grade ductal carcinoma in situ, after radiation therapy, a boost dose of radiation is given to the area where the tumor was situated to reduce its recurrence and to prevent it from getting into invasive cancer. The radiation boost effectively reduced ipsilateral (same side of the body) breast tumors. A lumpectomy followed by radiation therapy is an effective way to minimize ductal carcinoma in situ. A booster dose of radiation follows this procedure, suggested to avoid the recurrence of cancer.
There are 25 radiation therapy treatments for whole breast radiation. One radiation treatment for five days a week for seven weeks. Gray is the unit of measuring radiation dose. During each treatment, patients receive 1.8 to 2 gray of radiation. After a complete radiation therapy schedule of five to seven weeks, patients receive a total of 45 to 50 gray of radiation. In a hypofractionated schedule (higher dose of radiation in fewer appointments), the same radiation dose is received in three to five weeks duration, that is, 40 gray of radiation in 15 doses or appointments. Studies show that hypofractionated schedules are more effective than normal radiation treatment appointments. Tangential fields treat radiation boost by using cobalt 60 photobeams with a dose of 40 to 50 gray, which is done in 15 to 25 daily fractions.
Conclusion:
Ductal carcinoma in situ is not a life-threatening disease. However, it will develop into invasive breast cancer if not treated properly. Twenty percent of breast cancers are ductal carcinoma in situ. Radiation therapy is usually given after breast-conserving therapy to prevent cancer recurrence. A booster dose of radiation is also given to prevent further recurrence later.
