To remove a breast tumor, a mastectomy or a lumpectomy (also known as a partial mastectomy) can be performed. A mastectomy removes all of the breast tissue, while a lumpectomy only removes the part of the breast with the tumor and a small margin of surrounding breast tissue.[1] A double mastectomy fully removes both breasts and may be done if a woman is at a very high risk for getting breast cancer, such as women with a genetic predisposition like a BRCA gene mutation.[2] BRCA, known as the “BReast CAncer” gene, carries the most common inherited genetic mutation that leads to breast cancer.[3]

Surgery is often performed to remove tumors either before or after chemotherapy. If a tumor is very large, chemotherapy may be done before surgery to shrink the size of the tumor. This pre-operation chemotherapy can allow surgical operation on tumors that were previously too large to remove or allow a woman who would need a mastectomy to get a lumpectomy.[4] Otherwise, surgery is done first and the need for chemotherapy can be assessed based on factors such as gene expression testing[MBA1]  (looks at gene patterns to predict the likelihood of cancer recurrence) and if the cancer has spread to the lymph nodes.[5,6]

For early-stage cancers, women can typically choose between a lumpectomy and a mastectomy. A lumpectomy will conserve most of the breast tissue, but radiation therapy will most likely also be needed. Getting a mastectomy reduces the need for radiation. Studies have shown that for women who qualified for either type of surgery, a lumpectomy with radiation had the same survival rate as a mastectomy.[1]

When performing a lumpectomy, the margins must be assessed.[1] The margins are defined as the border of the tissue that is removed during surgery.[7] The goal of surgery is to remove all of the cancer and a small margin of the surrounding normal tissue. If cancer cells are found at the outside of the removed tissue, it is considered to have a positive or close margin and additional surgery may be needed. A negative margin means there are no cancer cells on the edge of the removed tissue.[1]

If the tumor is hard to find or difficult to reach, wire or needle localization may be used as a guide during breast cancer surgery. This process involves numbing the breast, guiding a thin, hollow needle into the area of the tumor using an ultrasound or mammogram, inserting a wire into the needle, and then taking the needle out. A small hook keeps the wire in place. MRI may also be used in rare cases if the ultrasound and mammogram are not successful at imaging the tumor. Wire localization is also sometimes used as a guide for performing a biopsy.[1]

Lymph node involvement is an important measure of cancer spread because cancer cells that have broken off from the primary tumor either travel through the bloodstream or the lymph system. Cancer cells that travel through the lymph system often end up in the lymph nodes. If cancer is found in the lymph nodes, it is more likely to continue spreading to other locations.[8] In order to determine if the cancer has spread to the lymph nodes, some lymph nodes are removed, typically at the same time as the breast tumor. Axillary lymph node biopsy (ALNB) involves the removal of lymph nodes (usually less than 20) in the armpit region. However, the discovery that cancer has a tendency to spread to certain lymph nodes first has allowed the practice of conducting a sentinel lymph node biopsy (SLNB) which removes only one or a few lymph nodes.[1]

The sentinel lymph nodes are determined by injecting a dye and/or a radioactive substance into the tumor, the area around the tumor, or the area around the nipple. The path the dye follows as it is circulated by the lymphatic system is very likely be the same path the cancer would take.9 SLNB is beneficial because it reduces the risk of developing lymphedema (swelling), but it is typically not an option for women with inflammatory breast cancer or breast cancer that is locally advanced.[1,9] Locally advanced means the cancer has spread beyond the organ it started in, but has not spread to distant parts of the body.[10] If cancer is found in the lymph nodes removed during a SLNB, an ALNB may be performed to check additional lymph nodes for cancer spread. However, studies have shown that an ALNB may not be needed.

For cases of advanced breast cancer where it has spread to other parts of the body, surgery is very unlikely to cure it. However, it can be useful in eliminating or reducing symptoms or slowing the spread of the cancer in some situations. Some of these situations include if the tumor is causing pain, if it is pushing against the spinal cord, if it is causing a blockage of the liver, and/or if it is pushing against the skin and causing an open wound. Surgery can also be performed if the cancer spreads to areas such as the brain.[1]

For many women receiving surgery for breast cancer, breast reconstruction is an option. Breast reconstruction can be done during or after the lumpectomy or mastectomy. Women who receive a mastectomy may want reconstructive surgery to rebuild the breast mound, while women who receive a lumpectomy may choose reconstructive surgery to correct dimpling by adding fat to the area where the tumor was removed.1 Breast reconstruction can be done using implants, the woman’s own tissue, or a combination of both.11 Nipple-sparing mastectomies can be done in some cases; when this is not an option, surgery and/or tattooing can be used for nipple and areola reconstruction. Nipple prosthetics are another option.[12]

 [MBA1]Link to gene expression article