Breast Cancer

Breast cancer is cancer of breast tissue. Worldwide, it is the most common form of cancer in females, affecting approximately one out of twelve to thirteen women who reach age ninety at some stage of their life in the Western world. It is (after lung cancer) the second most fatal cancer in women. Because the breast is composed of identical tissues in males and females, breast cancer can also occur in males, but here the incidence is very low, less than 1 percent.

History of breast cancer

Breast cancer is one of the oldest known forms of cancer tumors. oldest description of cancer (although the term cancer was not used) was discovered in Egypt and dates back to approximately 1600 B.C. The Edwin Smith Papyrus, or writing, describes 8 cases of tumors or ulcers of the breast that were treated by cauterization, with a tool called "the fire drill." The writing says about the disease, "There is no treatment." At least one of the described cases is male. This papyrus is 5 meters long and is kept in the New York Historical Society. Scholars believe that the actual document is a copy of an original document from the 30th century before Christ. In any case, for centuries, physicians described similar cases in their practises, with the same sad conclusion. It wasn't until greater understanding of the circulatory system was added to the body of medical knowledge in the 17th century that doctors made the link to the lymph glands in the armpit. The French surgeon Jean Louis Petit (1674-1750) and later the Scottish surgeon Benjamin Bell (1749-1806) were the first to remove the lymph nodes, breast tissue, and breast muscle. Their successful work was carried on by William Stewart Halsted who started performing mastectomies in 1882. He became known for his Halsted radical mastectomy, a surgical procedure that remained popular up to the 1970's and was performed on Betty Ford.

Epidemiologic risk factors and etiology

It is important to have a model of causation of a disease in order to distinguish epidemiological risk factors or associations with disease, from the biological etiology and primary cause, secondary co-factors, and simple promoters of the disease, given the underlying primary cause. The first work on breast cancer epidemiology was done by Janet Lane-Claypon, who published a comparative study in 1926 of 500 breast cancer cases and 500 control patients of the same background and lifestyle for the British Ministry of Health.

Today, breast cancer, like other forms of cancer, is considered to be a result of damage to DNA. How this mechanism may occur comes from several known or hypothesized factors (such as exposure to ionizing radiation). Some factors lead to an increased rate of mutation (exposure to estrogens) and decreased repair (the BRCA1, BRCA2 and p53 genes). Although many epidemiological risk factors, and biological co-factors and promoters have been identified, the majority of breast cancer incidence remains unattributable, and the primary cause is unknown.

Dietary influences have been proposed and examined, but these are small effects, and do not distinguish differences in risk within populations, as well as they do between populations.

A significant environmental effect was revealed by the large difference in breast cancer incidence between countries and continents, and a migration effect which slowly increases the risk of breast cancer even across generations after migration from a country of lower incidence to a country of higher incidence, such as moving from China or Japan to the United States.

Humans are not the only mammal prone to breast cancer. Some strains of mice, namely the house mouse (Mus domesticus) are prone to breast cancer which is caused by infection with the mouse mammary tumour virus (MMTV or "Bittner virus" for its discoverer Hans Bittner), by random insertional mutagenesis. Suspicion of MMTV or other viruses in human breast cancer is controversial, and the idea is not generally accepted for lack of direct and definitive evidence. There is much more research in diagnosis and treatment of breast cancer than in its cause.

Age

The risk of getting breast cancer increases with age. For a woman who lives to the age of 90 the chances of getting breast cancer her entire lifetime is about 12.5% or one in eight. Men can also develop breast cancer, but their risk is less than one in 1000 This risk is modified by many different factors. In a very small (~ 5%) proportion of breast cancer cases, there is a strong inherited familial risk.

The probability of breast cancer rises with age but breast cancer tends to be more aggressive when it occurs in younger women. One type of breast cancer that is especially aggressive and disproportionately occurs in younger women is inflammatory breast cancer. It is initially staged as Stage IIIb or Stage IV. It also is unique because it often does not present with a lump so that it often is not detected by mammography or ultrasound. It presents with the signs and symptoms of a breast infection like mastitis.

Genes

Two genes, BRCA1 and BRCA2, have been linked to the rare familial form of breast cancer . Women in families expressing mutations in these genes have a much higher risk of developing breast cancer than women who do not. Not all people who inherit mutations in these genes will develop breast cancer. Together with Li-Fraumeni syndrome (p53 mutations), these genetic aberrations determine around 5% of all breast cancer cases suggesting that the remainder is sporadic. Recently it was found that newly discovered gene called BARD1 if exists in combination with BRCA2 gene may increase the risk of breast cancer to as much as 80 percent 1. Genetic counseling and genetic testing should be considered for families who may carry a hereditary form of cancer.

Alcohol

Alcohol generally appears to increase the risk of breast cancer in women. The studies confirm previous observations that there appears to be an association between alcohol intake and increased risk of breast cancer in women. On balance, there was a weak association between the amount of alcohol consumed and the relative risk."

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) concludes that "Chronic alcohol consumption has been associated with a small (averaging 10 percent) increase in a woman's risk of breast cancer. According to these studies, the risk appears to increase as the quantity and duration of alcohol consumption increases. Other studies, however, have found no evidence of such a link.

"The new research estimates that a woman drinking an average of two units of alcohol per day has a lifetime risk of developing breast cancer 8% higher than a woman who drinks an average of one unit of alcohol per day. The risk of breast cancer further increases with each additional drink consumed per day. … The research also concludes that approximately 6% (between 3.2% and 8.8%) of breast cancers reported in the U.K. each year could be prevented if drinking was reduced to a very low level (i.e. less than 1 unit/week)."

It has been reported that "Two drinks daily increase the risk of getting breast cancer by about 25 percent." (NCI) but the evidence is inconsistent. The Framingham study has carefully tracked individuals since the 1940s. Data from that research found that drinking alcohol moderately did not increase breast cancer risk (Wellness Facts). Similarly, research by the Danish National Institute for Public Health found that moderate drinking had virtually no effect on breast cancer risk.

Breast cancer constitutes about 7.3% of all cancers . Among women, breast cancer comprises 60% of alcohol-attributable cancers. One study suggests that women who frequently drink red wine may have an increased risk of developing breast cancer.

"Folate intake counteracts breast cancer risk associated with alcohol consumption" and "women who drink alcohol and have a high folate intake are not at increased risk of cancer" . Those who have a high (200 micrograms or more per day) level of folate (folic acid or Vitamin B9) in their diet are not at increased risk of breast cancer compared to those who abstain from alcohol . Foods rich in folate include citrus fruits, citrus juices, dark green leafy vegetables (such as spinach), dried beans, and peas. Vitamin B9 can also be taken in a multivitamin pill.

Obesity

Gaining weight after the menopause can increase a woman's risk. Putting on 9.9kg (22lbs) increased the risk of developing Light levels

Researchers at the National Cancer Institute and National Institute of Environmental Health Sciences have concluded a study that suggests that artificial light can be a cause of breast cancer.

Hormones

The International Agency for Research on Cancer (IARC) in Lyon, France invited 21 scientists from eight countries in June 2005, to evaluate the risk of cancer for humans of combined estrogen-progesterone contraceptives and combined estrogen-progesterone menopausal therapy. The working group found that there is a small increase in the relative risk of breast cancer in current and recent users of combined oral contraceptives

The risk decreases to that of those who have never used such combined therapy ten years after cessation of use. The scientists described combined oral estrogen-progesterone contraceptives as "carcinogenic to humans." They also found an increased risk of breast cancer in women under treatment with combined menopausal therapy, which is confined mostly to current or recent users, increases with duration of use and exceeds that in women taking estrogen-only therapy .

Other

Other established risk factors include not having children, delaying first childbirth, not breastfeeding, early menarche (the first menstrual period), late menopause, obesity and taking hormone replacement therapy.

Unproven

It has been hypothesized that abortion may increase the risk of breast cancer because of hormones in early pregnancy. Recent large studies do not support this association.
Although not well quantified there has long been a concern about risk associated with environmental estrogenic compounds, such as dioxins, or phytoestrogens such as found in soy beans. ^]
Aluminum salts such as those used in anti-perspirants have recently been classified as metalloestrogens. In research published in the Journal of Applied Toxicology, Dr. Philippa D. Darby of the University of Reading has shown that aluminum salts increase estrogen-related gene expression in human breast cancer cells grown in the laboratory.

Symptoms

 Early signs of Breast Cancer

Early breast cancer causes no symptoms and is not painful. Usually breast cancer is discovered before any symptoms are present, either on mammography or by feeling a breast lump. A lump under the arm or above the collarbone that does not go away may be present. Other possible symptoms include breast discharge, nipple inversion and changes in the skin overlying the breast.

Screening

Due to the high incidence of breast cancer among older women, screening is now recommended in many countries. Screening methods suggested include breast self-examination and mammography. Only mammography has been proved to reduce mortality from breast cancer. In some countries routine (annual) mammography of older women is encouraged as a screening method to diagnose early breast cancer.

Normal (Left) versus cancerous (right) mammography image.

Mammography is still the modality of choice for screening of early breast cancer. Magnetic resonance imaging (MRI) has been shown to detect cancers that are not visible on mammograms, but it has several disadvantages. For example, although it is more sensitive, it is less specific than mammography. As a result, MRI studies will have more false positives, which may have undesirable financial and psychological costs. It is also a relatively expensive procedure, and one which requires the intravenous injection of a chemical agent to be effective. It may be valuable for younger women, whose breasts are denser with less fat and more connective tissue, making it harder to spot cancers on mammograms. Ultrasound alone is not adequate as a screening tool but it is a useful additional investigation, especially for the characterization of benign tumours.

The U.S. National Cancer Institute recommends screening mammography with a baseline mammogram at age 35, mammograms every two years beginning at age 40, and then annual mammograms beginning at age 50. In the UK, women are invited to attend for screening once every three years beginning at age 50. Women with one or more first degree relatives (mother, sister, daughter) with premenopausal breast cancer should begin screening at an earlier age. It is usually suggested to start screening at an age that is 10 years less than the age at which the relative was diagnosed with breast cancer.

Breast cancers detected by mammography are usually smaller than those detected clinically, and women who undergo mammography are more likely to be eligible for breast-conserving therapy.

Parenting Tips  Ayurveda  Burn Fat  Cure for Depression  Liver Cirrhosis  Breast Cancer  Stay Fit  Mesothelioma India  Doctors Hub  

Breast cancer in males

For years the medical profession assumed that male breast cancer was significantly different from female breast cancer. Today they are grouped together and receive the same treatment regimens. Since the male breast tissue is confined to the area directly behind the nipple, treatment for males has always been a mastectomy. Since the psychological effects of this surgery are just as great for males as for females, experimental surgery has been started to introduce the lumpectomy for males.

The incidence of breast cancer in males is very low, possibly due to the different endocrine milieu or the small total amount of glandular tissue. Seminal research in recognizing the incidence of male breast cancer was performed by the U.S. military at Madigan Army Medical Center. Most swelling or development of the male breast is likely to be the more benign condition of gynecomastia.

Top

Canceriscurable.org © All Rights reserved 2006. Spiderroost.com.