Breast Cancer & Exercise
To be published in American Fitness (AFAA) Oct/Nov Edition
By JP Saleeby, MD & Sharon K. Saleeby, RRT
Breast cancer is by far the most feared disease occurring in women despite its occurrence being second to lung cancer. It is estimated that just over 178,500 new cases of breast cancer will be diagnosed in the
Several well-established factors increase the risk of breast cancer. They include family history, nulliparity (not having had children), early menarche (starting menstrual cycles early), advanced age, excessive alcohol consumption, hormone therapy, a personal history of previous breast cancer, and exposure to environmental toxins such as tobacco smoke.
The most common types of breast cancer originate in either the breast's milk ducts (ductal carcinoma) or lobules (lobular carcinoma). The point of origin is determined by pathological appearance on biopsy. Cancers can be broken down into in situ and invasive. In situ means the cancer remains in its place of origin and has not invaded surrounding tissue.
Ductal carcinoma in situ (DCIS) refers to abnormal cells in the lining of a milk duct without surrounding invasion. Experts consider DCIS a "pre-cancerous" condition. This cancer is treated rather successfully and does not affect a woman’s life span. If left untreated however, it can become invasive. Lobular carcinoma in situ (LCIS) indicates abnormal cells that are contained within a lobule of the breast, without invasion of surrounding tissue. Researchers state that if you have LCIS, you are at an increased risk of developing breast cancer in either breast in the future.
Invasive or infiltrating breast cancers are those that extend beyond their origin, invading the surrounding tissues that support the ducts and lobules of the breast. The cancer cells can also travel to other parts of your body, for example the lymph nodes. When this process occurs it is called metastasis. Invasive ductal carcinoma (IDC) accounts for the majority of invasive breast cancers. This cancer starts in the lining of the milk duct and spreads to surrounding tissues and can metastasize to other locations in the body. Invasive lobular carcinoma (ILC) is not as common as IDC. ILC starts in the milk-producing lobule and invades the surrounding breast tissue. This cancer can also metastasize. The detection of ILC is difficult. Rather than detecting a “lump” one may perceive only a general thickening. ILC happens to be more evasive on a mammogram as well.
There are other less common or rare forms of breast cancer not all originating from the duct or lobule. They include: inflammatory breast cancer, medullary carcinoma, mucinous (colloid) carcinoma, Paget’s disease of the breast, tubular carcinoma, phylloides tumor, metaplastic carcinoma (less than 1% seen), sarcoma, micropapillary carcinoma (a very small but highly aggressive metastatic tumor) and adenoid cystic carcinoma (a large local tumor, yet slow growing).
Early education on self-breast exam and early screening is extremely important in achieving good outcomes. Self-exam and physician examination will detect cancer at a rate between 70 – 80%. Adding screening mammography (mammograms) will increase detection to 96 – 98%. It has been shown that early detection through clinical exam and mammography can reduce breast carcinoma mortality by 20 to 30%. Today’s gold standard for screening (mammograms) will still miss between 10 and 15% of these tumors (neoplasms).
Medical tests and diagnostics span the continuum between the very basic and the highly technical. The basic physical examination of the breast by the patient or physician is a starting point that may reveal a “lump”, odd texture of the skin, an enlarged lymphnode, or nipple discharge. The mammogram or the newer full-field digital mammography (FFDM) is another rather reliable screening tool and most often used in the
Screening should start with a baseline mammogram at age 35, or younger if there is a strong family history. Annual examinations should be performed once a woman reached 40 years of age. Self examination should be encouraged monthly starting at the age of twenty. If a clinically noted mass is followed by a negative mammogram the work up should then include a breast ultrasound and/or fine-needle aspiration cytology and close interval examinations. The newer modality of MRI is a method of examining the breasts that is far more sensitive in picking up smaller tumors than plain mammography. MRI is widely used in Europe, but has not yet taken on in the
A positive family history alone doubles the incidence of cancer increasing lifetime risk to approximately 25%. Recently the interest has focused on cancers associated with germ line (inherited) genetic mutations. While only 5 – 10% of all breast cancer sufferers have a mutation in BRCA1 gene (located on chromosome 17) and BRCA2 gene (located on chromosome 13), screening should be limited. Only when a patient’s first degree relative with known cancer and a positive mutation or a women falling into a certain ethnic group should testing be done. Women who have inherited a BRCA1 or BRCA2 mutation have a relatively high lifetime risk of breast cancer (about 50-85%). Risk for cancer in the opposite breast of a woman with a BRCA1 mutation is about 25%.
Once a tumor is detected important prognostic determiners such as stage of the disease, histology and nuclear grade, estrogen and progesterone receptor status and HER2/neu gene amplification tests are advisable. Staging determines treatment and prognosis. Staging is based on the T, N, & M nomenclature where T designates tumor size, N represents node involvement and M denotes any metastasis. For example T1N0M0 is a tumor 2-cm or less in diameter and has not spread to lymph nodes or distant sites. Once a pathologist knows the TNM characteristics he can stage the cancer. Staging ranges from 0 through IV (with III in subgroups of A & B). So a Stage 0 is non invasive, I & II are early stages, II with lymph node involvement and III are later stages and Stage IV is considered advanced.
There are several treatment options for breast cancer. Surgery to remove the tumor depends on the stage, but if caught early breast-conserving surgery (lumpectomy) is considered followed by radiation therapy. More aggressive tumors with lymphnode involvement will generally require mastectomy. Adjuncts to surgery include the use of hormone therapy, chemotherapy, and targeted or biological therapy. Radiation therapy (using measured doses) is very often supplemental, but holds very obvious untoward effects to surrounding tissues. It can be administered by external beam or by implanting radioactive seeds (brachytherapy). Scaring of skin and of the lung tissue is of greatest concern. Patient can develop a "radiation pneumonitis," which causes cough, shortness of breath and fevers three to nine months after completing treatment. This is important to consider when physical activity is planned.
Hormone therapy with the use of aromatase inhibitors (that reduce estrogen) such as Arimidex or Femara are used with women having hormone-receptor-positive breast cancer. Selective Estrogen Receptor Modulators (SERMs) like Tamoxifen or Raloxifene are also used to suppress future tumor growth. Another agent, Faslodex is an estrogen-receptor downregulator and is used in receptor positive cancer patients. Finally in the pre-menopausal woman with receptor positive cancer there are ways to shutdown ovarian function or remove the ovaries (oophorectomy).
Chemotherapy conjures up horrific images for women, with the loss of hair, the weakness and fatigue, anemia, and the intractable nausea and vomiting. While chemotherapy is a tough treatment modality it does result in significant reductions in the recurrence of breast cancer. Modern medicine offers women ways to combat the nausea and anemia with drugs like Zofran and Procrit & Epogen respectively.
There are many regiments of chemotherapy and is very physician dependent. A process called dose dense where therapy is administered every two weeks (instead of the typical three) has shown a greater reduction in recurrence rates. However, as you can imagine it is “harder” on the body. Drugs used in various combinations are Adriamycin, Cytoxan, Taxol, Methotrexate, fluorouricil (5-FU), and Taxotere.
The targeted or biological therapies are those agents that target a particular tumor which has certain genetic markers called HER2 genes. Drugs such as Herceptin, Tykerb and Xeloda are used in recurrent disease resistant to some of the anthracycline and taxane chemotherapeutic drugs. The agent Avastin which targets new blood vessels that feed cancer cells is often used in advanced cases and in combination with Taxol to slow progression of advanced breast cancer.
Physical activity during and after breast cancer treatment is important to maintain health. However limitations under the direction of the patient’s physician are important to heed. Depending on the types of treatments and any breast reconstructive surgeries the type and intensity of the exercise is important.
Research has strongly suggested that exercise is not only safe but also helpful during cancer treatment. It improves the physical functioning of the individual as well as enhances quality of life. Exercise has been shown to improve fatigue, self-esteem, reduce anxiety and maintain heart fitness, muscle strength and body composition. Those who have been exercising prior to chemo and radiation treatments may have to reduce the intensity and pace themselves a little slower while undergoing therapy. During chemotherapy there is a greater chance for bone fractures due to weakness and the increased risk of fall. Complicated routines and high impact exercise should be done with caution. Reports show that there is a five-fold increase in bone fracture in post-chemo breast cancer survivors due to bone density loss. So even after treatment is finished there is an increased risk for fractures. Recurrence of the breast cancer with mets to the bone can also cause fractures and is often times an early sign that the cancer has returned.
Depending on the type of treatments received there may be limitations to the types of exercise. For example those who are on chemotherapy and have become immunocompromised (thus susceptible to infection) should avoid the germs commonly encountered in public gyms until their white blood cells counts have returned to normal. Those receiving radiation may find the chlorine in the swimming pools an irritant to their skin. And those who suffer from severe anemia should delay any activity such as aggressive aerobic exercise or resistance training until their counts have normalized. Those who have not exercised prior to treatment should be started out with a low-intensity regiment and advanced rather slowly and cautiously. For older clients precaution should be taken to avoid falls as they may suffer from osteoporosis and arthritis. Those women who undergo breast reconstructive surgery may be limited in performing upper body resistance exercise until they are released to do so by their surgeon.
Recent reports in the medical literature show that exercising while young can reduce the incidence and/or delay occurrence of breast cancer. It should also be noted that exercise has been shown to reduce recurrence of breast cancer in breast cancer survivors.
It is extremely important for women to maintain annual physical exams and aggressive cancer screening regiments. There are means to help prevent cancer in high-risk women and exercise appears to be one modality.
A resource for more information on breast cancer is the American Cancer Society’s web site: http://www.cancer.org.
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JP Saleeby, MD is Medical Director of the Emergency Room at MPH in Bennettsville, SC. He sits on the advisory board of AFAA and performs online telemedicine consultation via www.saleeby.net.
Sharon K. Saleeby, RRT is a pediatric respiratory therapist at MUSC in Charleston, SC.
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References:
MayoClinic.com. http://www.mayoclinic.com (24 April, 2007)
Imaginis Breast Cancer Resource. http://www.imaginis.com/breasthealth/statistics.asp#1 (24 April, 2007)
Omni Medical Search: Breast Cancer Medical Tests and Diagnosis. http://www.omnimedicalsearch.com/conditions-diseases/breast-cancer-medical-tests.html (24 April, 2007)
BreastCancer.org. http://www.breastcancer.org/dia_pict_staging.html (24 April, 2007)
BreastCancer.org. http://www.breastcancer.org/treatment.html (24 April, 2007)
WebMD.org http://www.webmd.com/breast-cancer/guide/breast-cancer-treatment (24 April, 2007)
RadiologyInfo. (RSNA). http://www.radiologyinfo.org/ (24 April, 2007)
American Cancer Society. http://www.cancer.org/docroot/mbc/content/MBC_6_2x_FAQ_Nutrition_and_Physical_Activity.asp?sitearea=MH (24 April, 2007)
BreastCancer.org. http://www.breastcancer.org/cmty_trans_2006_01.html (24 April, 2007)
Doyle, C., et al., Nutrition and Physical Activity During and After Cancer Treatment: An American Cancer Society Guide for Informed Choices. CA Cancer J Clin,
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Holmes, M.D., et al, Exercise After Breast Cancer Treatment May Improve Survival and Reduce Recurrence. JAMA, 2005; 293:2479-2486
© 2007
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