Adjuvant vs. Neoadjuvant Chemotherapy
When therapy is given to patients with no evidence of cancer after surgery, it is called adjuvant therapy. Surgery is used to remove all of the cancer that can be seen, but adjuvant therapy is used to kill any cancer cells that may have been left behind but can’t be seen. Adjuvant therapy after breast-conserving surgery or mastectomy reduces the risk of breast cancer recurring.
Even in the early stages of the disease, cancer cells may break away from the primary breast tumor and spread through the bloodstream. These cells don’t cause symptoms; they don’t show up on imaging tests; and they can’t be felt during a physical exam. However, if they are allowed to grow, they can establish new tumors in other places in the body. The goal of adjuvant chemotherapy is to kill undetected cells that have traveled from the breast.
When chemotherapy is given before surgery is called neoadjuvant therapy. Generally, neoadjuvant therapy uses the same chemotherapy drugs that are used as adjuvant therapy (only it is given before surgery instead of after). The goal of neoadjuvant chemotherapy is to shrink large cancers so that they are small enough to be removed with less extensive surgery. Some breast cancers are too big to be surgically removed at the time of diagnosis. These cancers are referred to as locally advanced and have to be treated with chemotherapy to shrink them so they can be removed with surgery.
Personally, when I heard I had cancer, my first thought was, “get it out of me!” I am fortunate that mine was small and it could be removed right away. I didn’t find out until after getting the tumor pathology report back that I would have to undergo chemotherapy. That was another dark day for me. I was scared to death as anyone might be who hears they must have chemotherapy.
Chemotherapy is most effective when combinations of more than one drug are used. Many combinations are being used, and it’s not clear that any single combination is clearly the best. Clinical studies continue to compare today’s most effective treatments against something that may be better.
Some of the most commonly used drug combinations are:
- CMF: cyclophosphamide (Cytoxan®), methotrexate, and 5-fluorouracil (fluorouracil, 5-FU)
- CAF (or FAC): cyclophosphamide, doxorubicin (Adriamycin®), and 5-fluorouracil
- AC: doxorubicin (Adriamycin) and cyclophosphamide
- EC: epirubicin (Ellence®) and cyclophosphamide
- TAC: docetaxel (Taxotere®), doxorubicin (Adriamycin), and cyclophosphamide
- AC → T: doxorubicin (Adriamycin) and cyclophosphamide followed by paclitaxel (Taxol®) or docetaxel (Taxotere). Trastuzumab (Herceptin) may be given with the paclitaxel or docetaxel for HER2/neu positive tumors.
- A → CMF: doxorubicin (Adriamycin), followed by CMF
- CEF (FEC): cyclophosphamide, epirubicin, and 5-fluorouracil (this may be followed by docetaxel)
- TC: docetaxel (Taxotere) and cyclophosphamide
- TCH: docetaxel, carboplatin, and trastuzumab (Herceptin) for HER2/neu positive tumors
Other chemo drugs used to treat women with breast cancer include cisplatin, vinorelbine (Navelbine®), capecitabine (Xeloda®), liposomal doxorubicin (Doxil®), gemcitabine (Gemzar®), mitoxantrone, ixabepilone (Ixempra®), albumin-bound paclitaxel (Abraxane®), and eribulin (Halaven®).
I did not find out about all of these drugs and drug combinations until after I had started chemotherapy. At the time I met with my oncologist, I was only presented with a choice of 2 – AC → T (this regimen would be for a 20-week period) and TC (this regimen would be for a 12-week regimen). I just assumed that these were the only two specifically for breast cancer. I took the 12-week regimen which meant that I would have 4 treatments spaced 3 weeks apart. Make sure you understand ALL of your choices with regard to what drugs used and research the drugs so you fully understand the short- and long-term side effects.
How is Chemotherapy Given?
Doctors give chemotherapy in cycles, with each period of treatment followed by a rest period to give the body time to recover from the effects of the drugs. Chemotherapy begins on the first day of each cycle, but the schedule varies depending on the drugs used. For example, with some drugs, the chemo is given only on the first day of the cycle. With others, it is given every day for 14 days, or weekly for 2 weeks. Then, at the end of the cycle, the chemo schedule repeats to start the next cycle. Cycles are most often 2 or 3 weeks long, but it varies according to the specific drug or combination of drugs. Some drugs are given more often. Chemotherapy is generally given for a total time of 3 to 6 months, depending on the drugs that are used. Treatment may be longer for advanced breast cancer and is based on how well it is working and what side effects the patient is experiencing.
A drug to help boost the white blood cell count is given after each cycle of chemotherapy to make sure the white blood cell count returns to normal in time for the next cycle.
Possible Short-Term Side Effects
Chemotherapy drugs work by attacking cells that are dividing quickly, which is why they work against cancer cells. However, other cells in the body, like those in the bone marrow, the lining of the mouth and intestines, the fingernails and the hair follicles, also divide quickly so these cells are also likely to be affected by chemotherapy, which can lead to side effects. Some women have many side effects; others may only have few.
The side effects of chemotherapy depend on the type of drugs, the amount taken, and the duration of the treatments.
Some of the most common possible side effects include:
- Hair loss
- Low blood cell counts
- Nausea and vomiting
- Neuropathy, which is numbness, pain, burning or tingling sensations, sensitivity to cold or heat, or weakness in the hands and/or feet
- Chemo brain, which is a slight decrease in mental functioning, primarily regarding concentration and memory
- Mouth sores
- Loss of appetite
- Menstrual changes, premature menopause, infertility
Chemotherapy can affect the blood forming cells of the bone marrow, which can lead to:
- Increased chance of infections (from low white blood cell counts)
- Easy bruising or bleeding (from low blood platelet counts)
- Fatigue (from low red blood cell counts and other reasons)
These side effects are usually short-term and go away after treatment is finished. It’s important to tell your health care team if you have any side effects, as there are often ways to lessen them. For example, drugs are generally given to help prevent or reduce nausea and vomiting.
Possible Long-Term Side Effects
Heart damage: Some drugs may cause permanent heart damage (called cardiomyopathy). The risk of this occurring depends on how much of the drug is given, and is highest if the drug is used for a long period of time and/or in high doses.
Increased Risk of Leukemia: Certain chemotherapy drugs can permanently damage the bone marrow, leading to a disease called myelodysplastic syndrome or even acute myeloid leukemia, a life-threatening cancer of white blood cells. When this happens it is usually within 10 years after treatment.
Fatigue: This may last up to several years. Exercise, naps, and conserving energy may be recommended.