As part of a research medical center, physicians at the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in St. Louis have access to a wide range of clinical trials to test new therapies as they emerge. Many of our physicians are principal investigators in these trials.
Chemotherapy involves the administration of drugs, either orally or intravenously, to kill cancer cells. Therapy that falls under medical treatment has a wide range of approaches, including timing of treatment.
Neoadjuvant chemotherapy: Sometimes a tumor is too large to avoid a mastectomy or may be difficult to remove surgically. In those cases, neoadjuvant, or preliminary, chemotherapy and/or radiation and hormone therapy given before surgery can shrink the tumor and make it more removable.
After surgery: Most chemotherapy is given adjuvant (after surgery), sometimes combinations of drugs that have been shown to work well together for your type of cancer. Chemotherapy and radiation may both be given after surgery.
For tumors that are susceptible to estrogen, hormone therapy given over several years can reduce the risk of recurrence.
HER2, a cancer gene, is amplified in about 25 percent of human breast cancers. Herceptin, a monoclonal antibody to HER2, effectively treats HER2 amplified tumors; and the combination of chemotherapy and Herceptin greatly increases survival in HER2 amplified breast cancer. It is also used in metastatic cancers that have spread to other parts of the body. Herceptin recognizes and attacks the HER2 protein, to help overcome drug resistance with very few side effects. While it doesn’t cure metastatic disease, it can slow its progress. Several newer anti-HER2 drugs are also available, including pertuzumab (also called Perjeta, a monoclonal antibody to a different part of HER2), ado-trastuzumab emtansine (also called Kadcyla, Herceptin bound to chemotherapy), and lapatinib (also called tykerb, a small molecule inhibitor that inhibits the signaling transduction of HER2).
This is a treatment that stimulates the patient’s immune system to fight disease. Siteman researchers are now participating in clinical trials to test this form of therapy. Immunotherapy includes immune checkpoint inhibitors, vaccines, monoclonal antibodies, and biologic therapy.
Triple-negative breast cancer is a subset of all breast cancer
Some breast cancers do not have estrogen receptors, progesterone receptors, or large amounts of HER2/neu protein. The most successful treatments for breast cancer target these receptors. Because of its triple negative status, however, these tumors generally do not respond to receptor targeted treatments. Depending on the stage of its diagnosis, triple negative breast cancer can be particularly aggressive, and more likely to recur than other subtypes of breast cancer. Siteman has clinical trials of immunotherapies for these patients.
Monoclonal antibody therapy
This cancer treatment uses antibodies made in the laboratory, from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells, also in combination with chemotherapy.
A novel vaccine study under way at Siteman and two other centers is aimed at slowing the progress of metastatic breast cancer. Researchers at these three institutions are looking at MUC-1, a protein that is overexpressed on breast cancer cells and in many other cancers. By producing a double antibody and containing it in a vaccine, they hope to stimulate the patient’s immune system to respond strongly and produce both antibodies and T-cells, which would cause a regression of the cancer. Clinical trials may show the vaccine can also be given in early cancer.
Molecularly targeted therapy
These are treatments that are designed to attack the molecular alterations that make the cancer cell grow and spread. These treatments have the potential to be more effective and with less side effects than chemotherapy. Several molecularly targeted therapies has been approved by FDA, including everolimus (afinitor), and palbociclib (Ibrance). A number of molecular targeted therapies are in clinical trials that Siteman Cancer Center investigators are leading.
Surgery to remove cancer from the breast tissue and any affected lymph nodes is the most common procedure used to treat breast cancer. Depending on the diagnosis, surgery can be done as a stand-alone procedure, or in conjunction with other therapies. That’s why a specific diagnosis and staging are so important. Improvements in technology, such as special optical systems that can “see” cancer cells, are making breast cancer surgery more accurate and shorter.
Depending on the biology and genetics of the tumor, patients will often be recommended to have neoadjuvant chemotherapy before surgery for one of several reasons:
1. If the tumor size was marginal for a lumpectomy and the chemotherapy makes it shrink, you could become a good lumpectomy candidate.
2. If the tumor is HER(2)neu-positive, Herceptin and any other drugs approved to treat it are only approved for neoadjuvant use. It also allows systemic treatment for aggressive tumors like triple-negative breast tumors.
If you are going to have a mastectomy or a lumpectomy, breast reconstruction surgery may be done during the same procedure or at a future time. When you see the Siteman breast cancer surgeon and would benefit from having reconstructive surgery, an appointment with the plastic surgeon can often be arranged for the same day. Then the oncologic surgeon and plastic surgeon coordinate schedules for a combined surgery. Siteman is one of the quickest to schedule these combined surgeries, and surgery can usually be done within two to three weeks. More than 95 percent of patients who want reconstruction can have it done during the same procedure as the mastectomy or lumpectomy.
This surgery removes the whole breast that has cancer. Some of the lymph nodes under the arm may be removed for biopsy at the same time as the breast surgery or after, through a separate incision.
This involves an operation to remove the cancer but not the breast itself, and includes the following:
Lumpectomy: Surgery to remove a tumor (lump) and a small amount of normal tissue around it.
Partial mastectomy: Surgery to remove a larger part of the breast than for a lumpectomy, taking the cancer and some normal tissue around it. This procedure is also called a segmental mastectomy.
Skin and Nipple-sparing Mastectomy: Siteman has the largest volume of this type of procedure in St. Louis and most of the U.S. When possible in appropriate patients, this procedure makes doing reconstruction much easier and prevents having to reconstruct the nipple at a later time. The Siteman Cancer Center has done more than 500 of these on patients whose tumors were not too close to the nipple or the breasts were not too large to make it cosmetically feasible.
Lumpectomy with breast reduction: For women with large breasts, the surgical oncology and plastic surgery team can do a breast size reduction, starting on the cancer side to make sure the tissue removed contains the lump and a clean margin. Then the other breast is reduced to match.
External beam radiation
Ninety-five percent of radiation treatment at Siteman is external beam from outside the body. Siteman fine-tunes the radiation planning with intensity modulated therapy, using a large-bore CT simulator for 3D or full positioning to precisely target therapy. They were the first in the world to have the ability to do external radiation with MRI guidance, and the first to treat patients with that technology. The tumor cavity is better visualized on MRI than CT to minimize radiation dose to normal breast tissue, heart and lungs. Radiation is given daily over several weeks.
Called brachytherapy, this type of radiation is good for smaller primary tumors, negative surgical margins and negative lymph nodes. Siteman is a Center of Excellence for brachytherapy. The newer version is much more targeted than the older mammosite. With state-of-the-art equipment, the radiation oncologist can insert a multi-channel applicator into the breast at the site of the previous tumor. The applicator stays in place for 7 to 10 days, and delivers a twice-a-day intense radiation dose internally for five days and then is removed. The use and artful placement of the applicator sculpts the radiation dose away from adjacent ribs, skin and organs. It can also be used after external radiation treatment as a boost for cavities in young patients and those with unclear surgical margins.
Other radiation-related treatments useful to breast cancer patients include:
Hyperthermia: This novel therapy not used elsewhere in the St. Louis region involves heating superficial breast tissue to sensitize it to radiation treatment, especially for recurrent chest wall or inflammatory breast cancer. It increases the benefit of the radiation therapy without upping the radiation dosage.
Proton beam: Siteman has the only proton facility in Missouri. It is only applicable to specific cancers, mostly for patients with recurrent disease and prior radiation to decrease dosage of retreatment to organs.