June 23rd, 2012 by Hasham
What is prevention?
Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.
To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.
Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.
Different ways to prevent cancer are being studied, including:
* Changing lifestyle or eating habits.
* Avoiding things known to cause cancer.
* Taking medicines to treat a precancerous condition or to keep cancer from starting.
What can I do to reduce my risk of breast cancer?
Breast cancer prevention begins with various factors you can control. For example:
* Limit alcohol. The more alcohol you drink, the greater your risk of developing breast cancer. If you choose to drink alcohol — including beer, wine or liquor — limit yourself to no more than one drink a day.
* Control your weight. Being overweight or obese increases the risk of breast cancer. This is especially true if obesity occurs later in life, particularly after menopause.
* Get plenty of physical activity. Being physically active can help you maintain a healthy weight, which, in turn, helps prevent breast cancer. For most healthy adults, the Department of Health and Human Services recommends at least 150 minutes a week of moderate aerobic activity (think brisk walking or swimming) or 75 minutes of vigorous aerobic activity (such as running), in addition to strength training exercises at least twice a week. If you’re just starting a physical activity program, start slowly and build intensity gradually.
* Breast-feed. Breast-feeding may also play a role in breast cancer prevention. The longer you breast-feed, the greater the protective effect.
* Discontinue hormone therapy. Long-term combination hormone therapy increases the risk of breast cancer. If you’re taking hormone therapy for menopausal symptoms, ask your doctor about other options. You may be able to manage your symptoms with non-hormonal therapies, such as physical activity. If you decide that the benefits of short-term hormone therapy outweigh the risks, consider using the lowest dose that’s effective for your symptoms, and plan to use it only temporarily.
* Avoid exposure to environmental pollution. While further studies are needed, some research suggests a link between breast cancer and exposure to the polycyclic aromatic hydrocarbons found in vehicle exhaust and air pollution.
Can a healthy diet prevent breast cancer?
Research shows that eating a diet rich in fruits and vegetables doesn’t offer direct protection from breast cancer. In addition, a recent study of dietary fat and breast cancer showed only a slight decrease in the risk of invasive breast cancer for women who ate a low-fat diet. However, eating a healthy diet may decrease your risk of other diseases, such as diabetes, cardiovascular disease and stroke. A healthy diet can also help you maintain a healthy weight — a key factor in breast cancer prevention.
Introduction to breast cancer prevention
For so many women, there is no more dreaded disease than breast cancer. Breast cancer elicits fears related to loss of body image and sexuality, surgery, and death. As is the case for most cancers, the exact cause of breast cancer is not clearly known. Furthermore, there is currently no cure for advanced disease, and there is no definitive way of preventing it.
Breast cancer also affects men. Male breast cancer accounts for about 1% of all breast cancers. Around 229,000 new cases of breast cancer are diagnosed each year in women in the U.S., while about 2,200 cases are diagnosed in men.
Our knowledge of how breast cancer develops is expanding rapidly. As a result, new medications are being developed to reduce the risk of breast cancer among those at high risk of contracting this disease. For the majority of women, lifestyle changes, a healthy diet, exercise, and weight reduction can also help reduce the chance of developing breast cancer. To date, the most important strategy in improving survival is still breast cancer screening and early detection. Breast cancer is the second leading cause of cancer deaths among women in the United States. The leading cause is lung cancer. One in every eight women in the United States develops breast cancer. The risk is even higher for women with previous breast cancer, those who have first-degree relatives with breast cancer, those with multiple family members with cancer, and those who have inherited “cancer genes.”
What are the biological causes of breast cancer?
Breast cancer cells, like all cancers, initially develop because of defects in the genetic material deoxyribonucleic acid (DNA) of a single cell. The human body is composed of trillions of cells. Inside the inner core (nucleus) of each cell is our DNA located on chromosomes. Every human cell has two sets of 23 chromosomes. Each set is inherited from one parent. DNA exists as long, spiraled strands on these chromosomes. Different segments along the DNA strands contain information for various genes. Genes are blueprints that provide genetic instructions for the growth, development, and behavior of every cell. Human DNA is thought to contain approximately 23,000 genes. Most genes carry instructions for the types and the amount of proteins, enzymes, and other substances produced by the cells. Genes also govern the sizes and the shapes of the organs by controlling the rate of division of the cells within these organs. (During cell division, a cell makes a duplicate copy of its chromosomes and then divides into two cells.) Some genes restrict cell division and limit tissue growth.
Defects on the DNA strands can lead to gene coding errors, which in turn can cause diseases. When genes that normally restrict cell growth and divisions are absent or defective, the affected cells can divide and multiply without restraint. The cells that divide and multiply without restraint enlarge (forming a tumor) and can also invade adjacent tissues and organs. These cells can further break away and migrate to distant parts of the body in a process called metastasis. The ability to multiply without restraint, the tendency to invade other organs, and the ability to metastasize to other parts of the body are the key characteristics of cancers — characteristics that are due to DNA defects.
The cancer-causing DNA defects can be acquired at birth (inherited) or may develop during adult life. The inherited DNA defects are present in every cell of the body. On the other hand, DNA defects that develop during adult life are confined to the descendants (products of cell divisions) of the single affected cell. Generally, inherited DNA defects have a greater tendency to cause cancers and cancers that occur earlier in life than DNA defects that develop during adult life.
Breast cancer: prevention and control
Breast cancer is the top cancer in women both in the developed and the developing world. The incidence of breast cancer is increasing in the developing world due to increase life expectancy, increase urbanization and adoption of western lifestyles. Although some risk reduction might be achieved with prevention, these strategies cannot eliminate the majority of breast cancers that develop in low- and middle-income countries where breast cancer is diagnosed in very late stages. Therefore, early detection in order to improve breast cancer outcome and survival remains the cornerstone of breast cancer control.
The recommended early detection strategies for low- and middle-income countries are awareness of early signs and symptoms and screening by clinical breast examination in demonstration areas. Mammography screening is very costly and is recommended for countries with good health infrastructure that can afford a long-term programme.
Many low- and middle-income countries that face the double burden of cervical and breast cancer need to implement combined cost-effective and affordable interventions to tackle these highly preventable diseases.
WHO promotes breast cancer control within the context of national cancer control programmes and integrated to noncommunicable disease prevention and control. WHO, with the support of Komen Foundation, is at present conducting a 5-year breast cancer cost-effectiveness study in 10 low- and middle-income countries. The project includes a programme costing tool to assess affordability. It is expected that the results of this project will contribute to provide evidence for shaping adequate breast cancer policies in less developed countries.