​By Cassandra Foens, M.D., FACR

​Did you ever wonder why some women get chemotherapy but others don’t? Or why some women are eligible for shorter courses of radiation than others? There are reasons why we choose some treatments and not others for patients. All cancer treatment falls in to one of three categories: surgery, radiation therapy and drug therapy either with true chemotherapy, or hormonally based therapies or now more targeted drugs.

Each one of these therapies functions differently in the human body and so we choose between them based on what we believe is the most likely problem associated with the cancer. Surgery is certainly important in breast cancer. The goal of surgery is to remove any obvious cancer from the breast and assess the status of the lymph nodes.

Almost all breast cancer patients will undergo surgery, but patients must remember that the surgeon can only remove what he or she can see. Removing the tumor from the breast is important, but will not necessarily prevent the cancer from showing up later in other places in the body or even in the breast itself, in patients who have had a lumpectomy.

That is why surgery is rarely used alone in breast cancer. We consider surgery to be a local treatment – that means it only works in the local area where the surgery is done. Radiation therapy is also a local therapy. The advantage to radiation is that we can treat a larger area than the surgeon may be able to remove. We can also treat areas that the surgeon may not be able to reach, such as certain lymph node areas.

Radiation is also very good at killing any microscopic cancer cells – cells that may be present but cannot be seen with the naked eye. This is why surgery and radiation are often done together in many cancers – the surgeon removes the actual mass that he can see, and the radiation cleans up any cancer that may be left behind microscopically.

All women who have had a lumpectomy should be offered radiation therapy after surgery, and at least some women who have had a mastectomy need to be considered for radiation as well. Unlike surgery or radiation, drug therapy is a systemic therapy – it treats the whole body. The obvious advantage here is that you do not need to know where all the cancer cells are to treat them – both surgery and radiation require a target.

However, because the whole body is exposed to the drug used, side effects can occur far away from the location of the original cancer. We usually define chemotherapy as the use of certain chemicals that are toxic to cancer cells given by IV therapy, but that definition is changing. Certain traditional chemotherapy drugs are now available orally.

Since breast cancer can be a hormone-dependent cancer in some women, some oral endocrine therapies may be useful in changing the patient’s hormonal status to affect cancer growth. And there are newer drugs that target certain molecules known to be important in cancer growth – factors that can increase blood supply in a cancer mass, or growth factors that cancers make to encourage growth.

So how do we decide? We want patients to have both local control and systemic control. So for local control we rely on surgery followed by radiation therapy in women who choose lumpectomy. For patients who choose mastectomy, radiation therapy usually is not needed unless the patient has risk factors predicting an increased chance of local recurrence – these are things like a large tumor, positive lymph nodes, skin involvement, etc.

Systemic therapies are added when we believe there is a risk that the cancer will spread beyond the breast and/or lymph nodes. In older women with cancers sensitive to estrogen, endocrine therapies such as Tamoxifen or Arimidex may be sufficient. In younger women or women who do not have estrogen sensitive tumors, chemotherapy with drugs such as Adriamycin, Cytoxan, Taxol, 5FU and other may be needed.

If we test the tumor and see that it has markers for certain growth factors, then some of the newer targeted agents may be used – for example in women who have the Her2Neu marker present, they will likely receive Herceptin, while someone who does not have this marker will not get this drug. As you can see, this can be a complex decision making process – that is the reason that multidisciplinary evaluation of breast cancer patients is so important.

If a woman can be evaluated by a surgeon, a radiation oncologist and a medical oncologist before she makes any decisions about how she wants to treat her cancer, she has a better chance of making good informed decisions about her healthcare. 

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By Chris Hagness, Ph.D

eBx™ (electronic brachytherapy), a new breast cancer treatment, is now available close to home. This treatment is best for early stage invasive breast cancer (stage I) in post menopausal women (ages 60+), and is used to treat a lumpectomy site. This treatment may also be used in specific situations for some patients, determined on a case-by-case basis.

Used after lumpectomy, Accelerated Partial Breast Irradiation (APBI) differs from External Radiation Therapy in two ways. First, it reduces the treatment area from the entire breast to the area of the breast immediately around the lumpectomy site. This is the part of the breast where most cancers are likely to recur. Second, it shortens the treatment time from 5-7 weeks to 5 days. Since the duration of treatment is shorter, radiation is delivered in fewer fractions at larger doses per fraction.

eBx™ is beneficial to the patient in many ways:

• More intense therapy to cancer sites with minimal radiation exposure to surrounding healthy tissue (like the heart and lungs).
• Designed to deliver nonradioactive, isotope-free radiation treatment in a minimally-shielded clinical setting under the supervision of a radiation oncologist.
• Delivers electronically generated radiation directly to tumor beds by the use of disposable, miniaturized x-ray radiation sources.
• Designed to mimic the dose rate and isodose curves of an Iridium-based system in the treatment site while reducing extraneous dose as compared to MammoSite. This means that medical physicists and radiation oncologists are able to implement currently used treatment protocols while switching from radioisotopes delivered by High Dose Rate (HDR) afterloader to electronic brachytherapy delivered by a Xoft Axxent Controller.
• Does not require replacement of radioactive sources used with Mammosite and avoids safety issues of handling and disposal of radioactive materials.

This new cutting-edge technology and state-of-the-art treatment is available at Covenant Cancer Treatment Therapy department to patients in our community. Their radiation oncologists will be working closely with general surgeons throughout Northeast Iowa to ensure women who fit the criteria benefit from this new technology.

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