Exercise & Breast Cancer

Running head: EXERCISE AND BREAST CANCER

Exercise and Breast Cancer

Approximately 211,000 women in the U.S. are diagnosed with breast cancer each year. Forty-thousand of those diagnosed lose their battle with this disease and die. Breast cancer is the most common and second biggest cancer killer, after lung cancer, among women. The number of women with breast cancer has risen by 81% in the past thirty-three years. These numbers are significant because although the death rate is decreasing, the incidence is rising. Every day, doctors and researchers are actively working toward finding ways to prevent breast cancer and the risks it poses to women. Great strides are being made every day, and there have been great advances throughout the years. One of these advances has been the effects of exercise in lowering the risk of breast cancer and preventing recurrences in those who have previously been diagnosed, and what role it plays in the prevention and recovery of breast cancer. There is a plethora of research and findings that have surfaced and been published that show the support for exercise being a positive factor in preventing and lowering the risk of breast cancer and recurrence. Many studies have been performed throughout the last ten to twelve years that has focused solely on the issue at hand. Rachel Ballard-Barbash of the National Cancer Institute states, “We have emerging a growing field of research on the role of lifestyle factors on cancer quality of life after diagnosis and their potential effect on cancer survival and prognosis” (Stein, 2005). Throughout this paper, numerous literature will be presented that supports the findings of exercise’s positive influence on the prevention and lower risk of breast cancer. Every day, doctors and researchers throughout the world are working toward coming to a better understanding of breast cancer and its possible causes and risk factors. One of the key components they have stumbled upon that can aid in the prevention of breast cancer and help in those women recovering from the disease is exercise. Studies have been done on those with and without a history of breast cancer to determine whether or not exercise can reduce the risk of breast cancer. Other studies have also been done with women recovering from breast cancer and whether or not exercise benefits them throughout the recovery process. The two components that will be examined throughout this paper are exercise reducing the risk of breast cancer in women with and without a family history, and exercise as a benefit during recovery from breast cancer and how it affects the risk of recurrence. Exercise is a key component to living healthy because it helps build and maintain bones and muscles, helps control weight and reduce fat, and releases stress and helps develop a more positive outlook on life. Exercise can also reduce the risk of developing some of the leading causes of death and illness, such as breast cancer. Research is advancing its works and more and more studies are showing that exercise and breast cancer have a direct correlation to one another. Newer studies, along with some past ones, are showing that breast cancer may be affected by exercise. When looking for new information and performing studies, one factor that is looked at in determining the risk of breast cancer is exercise. Recent studies have shown that regular physical activity is effective in lowering the risk of several types of cancer, with breast cancer being among the top. According to both the Keck School of Medicine (University of Southern California) and the American Cancer Association, exercise cuts the risk of developing breast cancer and women who exercise daily have a 35% lower risk of developing breast carcinoma in situ than inactive women (“Exercise Keeps Breast Cells Working,” 2003). These findings coincide with another that says that aerobic exercise over a long period of time may reduce the risk of breast cancer. A study done by U.S. researchers showed results that women who have a long-term history of 5+ hours of strenuous exercise per week are 20% less likely to develop invasive breast cancer and 31% less likely to develop non-invasive (in situ) breast cancer than those who only exercised less than 30 minutes per week (Preidt, 2006). There has, though, been some debate upon whether or not the intensity of the exercise makes a difference in lowering the chances of developing breast cancer. Some studies have shown that moderate exercise will satisfy this need, while others lean towards strenuous exercise. In women who have never been diagnosed with breast cancer or are not in a remission stage, strenuous exercise seems to take precedence over light or moderate exercise. If the exercise is moderate, it may require more hours of physical activity each week to match the levels and benefits of strenuous exercise. Dr. Anne McTiernan’s (Fred Hutchinson Cancer Research Center in Seattle) study, though, sheds some light on moderate exercise. She claims that brisk walking for 1-2 hours/week can help reduce the risk of breast cancer by nearly 20%, and that women who engage in 1.25-2.5 hours/week of moderate exercise have an 18% lower risk of breast cancer than inactive women (Tanner, 2003). This opposes studies that say only strenuous exercise can decrease the risk at such a high rate. But Tiernan has found that there is little additional benefit from more intense/frequent exercise (Tanner, 2003). Another factor that plays a role in breast cancer is estrogen. In women, exercise has an immense effect on the levels of estrogen, female hormones, in the body (Patel, 2003). Estrogen plays a large role in breast cancer because it can fuel the growth of some breast cancers. Higher levels of estrogen put women at risk for developing breast cancer, so it would only make sense that the less estrogen present in the body, the lower the risk of developing breast cancer. Exercise is directly related to hormones and their growth in the body. According to the National Cancer Research Institute, strenuous physical activity reduces the production of female hormones, namely estrogen (Patel, 2003). Daily exercise or any kind of daily physical activity lessens the amount of estrogen produced and distributed throughout the body, therefore, lowering the risk of breast cancer from the estrogen standpoint. There is a clear link between activity and reduction in breast cancer based on the levels of estrogen present in an active woman and inactive woman, with exercising decreasing the amount of estrogen that is produced and released. An important physiological factor related to estrogen is menstruation. The National Cancer Research Institute has found that the risk of breast cancer can be reduced during pre-menstrual years and adolescence by exercising regularly, and because of the direct relationship between exercise and hormones, menstruation is affected as well (Crompton, 2006). It is common knowledge that during the menstrual cycle, ovulation occurs and hormones are released every month from this ovulation. Research has shown that the cumulative number of ovulatory cycles in a woman’s lifetime is an influence of breast cancer (Compton, 2006). In other words, the earlier a girl starts her period, the more it increases her chances of developing breast cancer later in life. Even though exercising later in life will prove to be beneficial in the fight against breast cancer, the most important time for a girl to begin exercising is at a young age, before menstruation. Exercising from an early age is most beneficial in the prevention of breast cancer later in life because it delays the first period. Professor Leslie Bernstein, chair in cancer research at the University of California, says, “When you compared the active girls with the inactive girls, they were two to three times more likely to experience, instead of full ovulation, a type of immature menstrual cycle where they don’t ovulate” (Swan, 2006). An immature menstrual cycle without ovulation means that if there is no ovulation, then the hormones released during this phase are not released in the same way as if there were ovulation. In this cycle, estrogen and progesterone are released in a limited capacity and these hormones are not as harmful to the body in the long run. This decreased level of hormone exposure will decrease the chances of breast cancer later in life. Physiological components that factor into breast cancer and exercise as a risk reducer are important to understand not only as a doctor, but as one of the potential victims as well. Another one of these factors, aside from menstruation and the release of female hormones, is body fat and metabolism. Research has found that being overweight can increase the risk of developing breast cancer (Patel, 2003). When a woman is overweight, her body has more than the average amount of fat on it. This is a risk factor because fat is another component in the body that can produce estrogen. When a woman is overweight, that extra fat on her body makes extra estrogen, which in turn increases the risk of breast cancer (Patel, 2003). So in this way as well as menstruation, estrogen works as a potential danger to the body. But again, exercise proves to be beneficial in this case, just as in the case of menstruation. A woman who exercises regularly will not only benefit herself in terms of keeping in shape and keeping healthy, but it is also a way to aid in the controlling of her weight. So far, the literature presented has shown that there is a great benefit to daily exercise, as many studies have shown that it helps in preventing and lowering the risk of breast cancer. There are, though, those who have not been so fortunate as to escape breast cancer. But research and studies have also shown that exercise helps in the treatment and recovery of breast cancer. Three different studies have shown that light to moderate exercise will increase the odds of survival during breast cancer and quicken/aid in the recovery from breast cancer. The first study was performed by Dr. Lesley Walker of the University of Bristol. As a trial study, she split breast cancer patients going through recovery into three groups: exercise suiting physical ability and incorporated into every day life, body conditioning with no daily routine, and standard treatment of breast cancer (chemotherapy and radiation treatment). At the end of the 8 week trial program and monitoring at three and six months, Walker found that the women who had an exercise program that suited their physical ability and were encouraged to include it into their every day life had the most positive results (“Exercise Boosts Recovery,” 2004). The second study was done by Michelle D. Holmes, from Harvard Medical School in Boston, and colleagues. This study, part of the Nurses’ Health Study, examined and collected data from 2,987 women who had been diagnosed with breast cancer and closely detailed their exercise routine (Stein, 2005). The final conclusions were that any amount of exercise seemed to increase the odds of survival, but the odds increased with activity of 3-5 hours per week (Stein, 2005). The more a woman exercises, the more the odds increased due to the decrease in hormones. Exercise decreases the hormone levels of estrogen and progesterone present in the body, therefore, reducing the risk of break cancer or recurrence. A third study showing the relationship between exercise and breast cancer was performed by the University of Southern California. Through this study, researchers looked at 567 women who had been diagnosed with breast cancer and were interviewed as to their exercise habits, menstruation, and history of breast cancer in their family (Patel, 2003). The results seemed to show something that previous studies either did not look at or failed to mention, which was whether or not exercise played a factor when a family history of breast cancer was included. In agreement with the previous studies, results showed that women who did not have a family history of breast cancer and exercised about 4+ hours a week had a 47% lower risk of developing breast cancer (Patel, 2003). But what this study showed that others did not was that women with a family history of breast cancer, whether it be a mother, sister, or daughter, did not seem to have any kind of link to exercise being a reduction factor in this disease (Patel, 2003). Some women carry a genetic predisposition to breast cancer, especially if it has been in the family throughout generations. While there may be benefits to exercise that reduce the risk in this situation, there was nothing significant that showed that exercise lowered the chances in this case as it did with no history at all. Despite these findings, there is ever-increasing hope for the breast cancer patient and better ways to cope with treatment and recovery, with exercise playing a major beneficial role. For many years, breast cancer patients going through treatment, including chemotherapy and radiation, were encouraged to get plenty of rest without physical activity in order to preserve whatever energy they had left. According to the American Cancer Society, most cancer patients receiving chemotherapy experience a loss of energy and fatigue, which is generally severe and limits physical activity, therefore leading to muscle wasting and loss of function (“Physical Activity,” 2007). But the ACS says that regular exercise or aerobic training can help break this cycle (“Physical Activity,” 2007 ). Exercising during treatment and recovery can not only help with reducing the amount of fatigue one feels, but it helps build the muscle back up by consistently using it every day. Generally, when people exercise, they either do it to build up muscle (for strength) or to tone their muscles. Chemotherapy makes a person so weak that they start to lose any kind of muscle mass and muscle tone they had before treatment. Also, exercising can lessen the other side effects of chemotherapy, which include weight gain, insomnia, reduced flexibility, and loss of libido (“Exercise Boosts Recovery,” 2004). As mentioned earlier, weight gain increases body fat, which produces extra estrogen that can cause breast cancer, and exercising during chemotherapy can help to prevent that extra weight gain during this time, therefore keeping estrogen levels down. Exercise helps with these side effects by keeping the body fit, loosening the muscles and increasing flexibility, and releasing endorphins to create energy. Other than helping to prevent the side effects of chemotherapy, exercising and keeping active can also help one feel good about their body. Regular exercise not only improves strength, but it also improves daily function physically and helps the immune level strengthen despite being broken down during chemotherapy. Breast cancer not only effects and weakens the immune system, but it also affects the epidermis, the gut, the bladder, the lungs, the stomach, and lymphatic system (“The Immune System,” 2006). The side effects of chemotherapy can be harmful to the lining of the gut and can cause bladder infections. Radiation treatment in the lung area can damage the hairs and mucus producing cells that help rid of bacteria (“The Immune System,” 2006). But exercising can be beneficial in this situation. This exercise will help people get back into the daily routine of doing the things they used to do before breast cancer and chemotherapy, such as yard work, housework, daily activities such as grocery shopping and working, and many more. Because exercise brings energy and life back into a breast cancer recovery patient, it can also provide hope and inspiration during treatment (Exercising and Treating Cancer) and improve their mental well-being (Steen, 2004; “Exercise Boosts Recovery,” 2004). The side effects can cause feelings of depression, lack of confidence, and low self-esteem, but exercising replaces these feelings with a sense of confidence and energy and hope. In a way, it is almost as if these feelings brought on by exercise are the patient’s way of saying, “I win. I’ve beaten this disease.” There have been a number of athletes who have beaten some type of cancer and regained their strength and confidence by competing in their sport again, which required some type of exercise to get to that point. It is people like that, namely Lance Armstrong, who prove that exercise is beneficial to the recovery process and will only strengthen a person in that situation. Sometimes, this exercise and physical activity provides the person with a sense of achievement and allows them to set goals and strive to reach those goals, which in turn boosts confidence levels and makes that person feel good about themselves again. Exercise during treatment and the recovery process allows for physical, emotional, and psychological victory over the disease (Steen, 2004). Dr. Amanda Daley of the University of Birmingham states, “Many women suffer from depression, anxiety, low self-esteem after treatment…struggle to regain confidence…exercise therapy after treatment can help women feel better and improve the quality of life” (“Exercise Boosts Recovery,” 2004). Over the years, more and more studies have popped up concerning breast cancer and ways of prevention, becoming a hot topic in the medical world as well as within communities around the world. Recent research has shown that exercise can play a key role in the prevention of breast cancer and in reducing the risk of developing the disease later in life. Studies have shown that regular exercise can decrease the risk of breast cancer due to the fact that regular exercise control body weight, also controlling body fat, which an increase in can produce extra estrogen. This extra estrogen released is a female hormone that can potentially cause breast cancer. It has also been shown that beginning exercise at a young age, pre-adolescence, has an affect on the chances of breast cancer. Recent studies have shown that exercising regularly pre-menstruation can cause a delay in the menstrual cycle, which produces estrogen during ovulation. Delaying this cycle makes the number of times of ovulation in a lifetime less, decreasing the amount of estrogen released, and in some cases, causing immature ovulation where no estrogen is released. Exercise has also been seen to be beneficial in the recovery process of breast cancer, reducing or ridding completely the side effects of chemotherapy. Exercising during treatment and recovery rebuilds muscle tone, reduces weight gain, and improves the immune system, which is a vital component to keeping healthy. During chemotherapy, the immune system is weakened by a drop in the number of white blood cells made in the bone marrow, which produces cells that fight infection. Exercising can help this by maintaining and increasing the number of white blood cells in the bone marrow. In my opinion, exercise is beneficial in helping breast cancer patients through treatment and recovery, and I also think it plays a key role in reducing the risk of developing the disease later in life. The results on this topic from studies makes it hard to disagree with this concept. The research and findings have been, in my opinion, convincing and legitimate. I learned a great deal about the relationship between exercise and breast cancer from my research. Before that, I did not think that exercise played any major role in preventing or reducing the risk of breast cancer. I think it is a great thing that there are ways for women to help themselves and play an active role in possibly reducing their risk of breast cancer by simply exercising regularly. It should encourage more women and more young girls to be active and have a daily routine that will only benefit them in the long run. Overall, this project was a learning experience and I researched a topic I otherwise would not have invested the time and effort in, so it was beneficial in that way. Women all over the world should be inspired by these results and encouraged to become physically active if they are not already. As Dr. Lesley Walker leaves says, “We continue to see encouraging results…thousands of women can benefit from exercise while in the near future, I hope to see an exercise routine becoming standard treatment for breast cancer” (“Exercise Boosts Recovery,” 2004).

Reference List
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