Adjuvant therapies for breast cancer treatment
Adjuvant breast cancer therapy is a term which encompasses all of the extra treatments which are applied to help prevent the breast cancer from returning. (By contrast, ‘neo adjuvant’ breast cancer therapy is given prior to any other treatments in order to improve the benefits of subsequent treatments). There are basically systemic breast cancer therapies.
- radiation therapy
- hormone therapy
- targeted therapy
The type and degree of adjuvant breast cancer therapy to apply will in large part be determined by of the specific type of cancer involved, and the cancer stage.
I just would like to inform you that I have created a newer version of this page with more up-to-date information on Adjuvant Breast Cancer Therapy. However, this page still has really great research material, so I would still use it as well as the new one.
Primary breast cancer therapies
Radiation therapy and surgery are usually considered to be the ‘primary‘ treatments, whereas adjuvant therapy is used to limit the chances of the breast cancer returning.
Breast cancer surgery can usually remove all of the malignant cancer cells, but adjuvant therapy is a way to kill off cancer cells which may have remained behind, or which have migrated undetected to other areas of the body.
There are many benefits to adjuvant therapies, but they are not without side effects, so the decision has to be weighed carefully.
Chemotherapy is ‘toxic’ to breast cancer cells
Chemotherapy is a broad term but it essentially refers to the use of drugs to ‘kill‘ cancer cells. There are various ways that breast cancer chemotherapy accomplishes this, but generally speaking it is through either interfering with the breast cancer cell’s ability to multiply, of by killing the cells themselves.
Chemotherapy is also called ‘systemic‘ therapy, because it reachers virtually every area of the body, not just a specific site. Sometimes chemotherapy is used as ‘primary‘ therapy, especially if the breast cancer is already at a later stage.
There can be many side effects from chemotherapy, but it can be a highly effective and beneficial modality of breast cancer treatment. Chemotherapy is administered by the oncologist, who is an expert in this area.
Hormone or Endocrine therapy for breast cancer treatment
A sub-category of breast cancer chemotherapy is ‘hormone‘ therapy (also termed ‘endocrine therapy‘). Hormones are like signals that the body creates in order to stimulate certain biological processes and functions, and one of the most important hormonal functions is as a signal for ‘growth‘, specifically cell growth.
Certain hormones act like ‘fuel‘ to stimulate breast cancer growth, which is of course the opposite of what is desired. Breast cancer hormone therapy acts in a way that either reduces the body’s production of certain hormones or by limiting a breast tumor’s ability to ‘accept‘ hormones.
When a breast tumor biopsy sample is examined by a pathologist, this ‘histological evaluation‘ will include information as to whether or not the breast cancer is sensitive to certain hormones.
In fact, if a breast cancer tumor is determined to be highly sensitive to ‘growth‘ hormones such as estrogen and progesterone, this is actually a positive thing. That means that the breast cancer can be effectively countered with hormone therapies which inhibit the ability of these hormones to function, slowing and possibly stopping breast tumor growth.
Radiation therapy is highly localized
Radiation therapy can either be considered primary or secondary breast cancer treatment. Radiotherapy uses high-powered X-rays focused on a very specific area of the body to kill breast cancer cells.
There are side effects to radiation therapy as it is quite hard on the body. In fact, some side effects might only surface many years after treatment. However, breast cancer radiation therapy in combination with surgery is a tried and tested method of breast cancer treatment.
Breast cancer immunotherapy supplements the body’s defense systems
Breast cancer immunotherapy is a relatively new approach to breast cancer treatment. Our own bodies have a powerful immune system in place to fight off infection and disease, and breast cancer immunotherapy is a means of ‘amplifying‘ the effectiveness of the body’s own defense systems.
It’s much like receiving a vaccination for the flu or measles, but on a larger scale. By placing antibodies or immune cells from someone else into a breast cancer patient’s system, the body’s own defenses receive a huge boost. Breast cancer immunotherapy is still considered an ‘experimental‘ breast cancer treatment, largely informed by advances fighting immune system diseases such as AIDS.
Physicians will tend to be cautious before utilizing this modality to fight breast cancer, but when the cancer is not responses to the usual treatments, it is a reasonable approach. There can be rather serious side effects to breast cancer immunotherapy, so the decision to proceed with it must be considered very carefully.
Targeted breast cancer therapy is specific to cellular abnormalities
“Targeted” breast cancer therapy is somewhat of a misleading term, as like hormone therapy, it is really a sub-category of breast cancer chemotherapy. What targeted therapy implies is that a highly specific abnormality found in an individual patient’s breast cancer cells is being ‘targeted‘.
By limiting the ability of a particular cellular abnormality to grow and flourish, the overall growth of the breast tumor may be slowed or even halted. As an example, some breast tumors over-express a protein called “HER2” , and high levels of this particular hormone have been shown to have a negative effect on overall prognosis.
By specifically targeting and blocking the action of this protein, breast cancer growth is inhibited.
Let’s do some Q&A…:
- Which treatments are used as adjuvant therapy? As listed above, chemotherapy, hormone therapy, radiation therapy, immunotherapy, as well as targeted therapy.
- How effective is adjuvant therapy? Because none of these treatenents is completely harmless, it’s important to determine the risks of adjuvant therapy vs. the benefits. The following factors can hekp you and your doctor determine whether adjuvant therapy is appropriate for you and, if so, which type: Type of cancer, stage of cancer, number of lymph nodes involved, hormone receptivity, and other cancer-specific changes. Receiving adjuvant therapy doesn’t guarantee your cancer won’t recur. It can, however, help reduce the risk that your cancer will come back.
- Is adjuvant therapy for you? As you’re deciding whether adjuvant therapy is right for you, you might want to discuss the following issues with your doctor: What procedures are you considering?, What are the side effects?, What are the changes you’ll stay cancer-free?, How is your overall health?, and What is your preference? Together you and your doctor can weigh these factors and decide whether the benefits of adjuvant therapy outweigh the risks for you.
- When is adjuvant therapy appropriate? Adjuvant therapy is often used after primary treatments, such as surgery or radiation. Adjuvant therapy given before the main treatment is called neoadjuvant therapy. This type of adjuvant therapy can also decrease the change of the cancer coming back, and it’s often used to make the primary treatment, such as an operation of radiation treatmentm easier or more effective.
- What are some side effects of adjuvant therapy? Depending on what form of treatment is used, adjuvant therapy can have side effects, like all therapy for neoplasms. Chemotherapy frequently causes vomiting, nausia, alopecia, mucositis, myelosuppression particularily neutropenia, sometimes resulting in septicaemia. Some chemotheraputic agents can cause acute myeloid leukaemia. Rarely, this risk may outweigh the risk of recurrence of the primary tumor. Depending on the agents used, side effects such as chemotherapy-induced peripheral neuropathy, bladder damage, constipation or diarrhea, hemorrhhage, or pose-chemotherapy cognitive impairment. Radiotherapy causes radiation dermatitis and fatigue, memory loss, headaches, alopeia, radiation necrosis of the brain, irratation, nausea, vomiting, diarrhea, prostatitis, proctitis, dysuria, cardiovascular disease, metritis, and abdominal pain can also occur, and other possibly severe side effects. Hormonal therapy may cause hot flashes, vaginal discharge, and nausea.
- Alvarez RH, Valero V, Hortobagyi GN.Emerging targeted therapies for breast cancer. J Clin Oncol. (July 2010) 28(20):3366-79. Epub 2010 Jun 7.
- Lo YH, Ho PC, Zhao H, Wang SC Inhibition of c-ABL sensitizes breast cancer cells to the dual ErbB receptor tyrosine kinase inhibitor lapatinib (GW572016)..Anticancer Res. (March 2011)31(3):789-95.
- Soliman, H., Developing an Effective Breast Cancer Vaccine. Cancer Control. 2010;17(3):183-190.
- Hortobagyi GN, Spanos W, Montague ED, et al. Treatment of locoregionally advanced breast cancer with surgery, radiotherapy, and combination chemoimmunotherapy. Int J Radiat Oncol Biol Phys. 1983;9(5):643–650.
- Mittendorf EA, Peoples GE, Singletary SE. Breast cancer vaccines: promise for the future or pipe dream? Cancer. 2007;110(8):1677–1686.
- Dent R, Trudeau M, Pritchard KI, et al. Triple-negative breast cancer: clinical features and patterns of recurrence. Clin Cancer Res. 2007;13(15 Pt 1):4429–4434
- Baxevanis CN, Perez SA, Papamichail M. Combinatorial treatments including vaccines, chemotherapy and monoclonal antibodies for cancer therapy. Cancer Immunol Immunother. 2009;58(3):317–324.
- Early Breast Cancer Trialists’ Collaborative Group. Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomised trials. Lancet 2005;365:1687-1717
- Muss HB, Woolf S, Berry D, et al. Adjuvant chemotherapy in older and younger women with lymph node-positive breast cancer. JAMA 2005;293:1073-1081
- Fisher B, Anderson S, Tan-Chiu E, et al. Tamoxifen and chemotherapy for axillary node-negative, estrogen receptor-negative breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-23. J Clin Oncol 2001;19:931-942
- Chlebowski RT, Anderson GL, Gass M, Lane DS, Aragaki AK, Kuller LH, Manson JE, Stefanick ML, Ockene J, Sarto GE, Johnson KC, Wactawski-Wende J, Ravdin PM, Schenken R, Hendrix SL, Rajkovic A, Rohan TE, Yasmeen S, Prentice RL; WHI Investigators. Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women. JAMA.(Oct. 2010);304(15):1684-92.
- Larinov, AA., Miller, WR., Challenges in Defining Predictive Markers for Response to Endocrine Therapy in Breast Cancer . Future Oncology. 2009;5(9):1415-1428
- Ellis MJ, Tao Y, Luo J et al.: Outcome prediction for estrogen receptor-positive breast cancer based on postneoadjuvant endocrine therapy tumor characteristics. J. Natl Cancer Inst. (2008)100(19), 1380–1388
- Ma CX, Ellis MJ: Neoadjuvant endocrine therapy for locally advanced breast cancer. Semin. Oncol. (2006)33(6), 650–656.
- Clarke M, Collins R, Darby S, et al. Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: an overview of the randomised trials. Lancet. (2005);366(9503):2087–2106.