What is Breast Cancer?? Breast Cancer Classification,Risk factors ,Clinical picture? and Breast Cancer Diagnosis
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Breast cancer is the rampant growth of malignant cells in the breast tissue. There are two main types of breast cancer, ductal carcinoma ? the most common ? which begins in the ducts that carry milk from the breast to the nipple and carcinoma lobular which starts in parts of the breast, called lobules, which produce milk materna.
The main risk factors for breast cancer include an advanced age, the first menstruation at an early age, elderly at the time of first birth or never giving birth, a family history of breast cancer, the fact of consuming hormones such as estrogen and progesterone, consume liquor and be of race blanca.2 between 5 to 10% of casesbreast cancer is caused by inherited genetic mutations.
Different tests as proof of receptors for estrogen and progesterone or magnetic resonance imaging, mammography, breast ultrasound with high resolution (ecografia) transducers are used to detect breast cancer. The diagnosis of breast cancer can only take the nature of definitive by breast biopsy. It is ideal to do biopsies for puncture or aspiration, fine needle, with gun Court, these guided by ultrasound or resonance or use biopsy equipment for cutting and vacuum, which are able to remove the lesion partially or completely, according to the case. These can be guided by Stereotactic (image mamografica guided by coordinates) or by ultrasound. If it is not possible, incisional biopsies can do (remove part of the mass) or excisionales (remove all the mass), this may alter the stadium of the tumor. Through ultrasound, there are new techniques that may suggest malignancy, such as doppler, 3D multicortes or elastografia, but all should be evaluated and only will have a definitive di?gnostico through a biopsy. Obviously, all the methods of image are characterizations of what may be a cancer or not, for which, the bi-RADs method, is used to decide the behavior according to that classification.
Of the total of breast carcinomas, less than 1% occur in males. The international day of the breast cancer held the octubre1 19, it aims to educate the general population about the importance of this disease in the industrialized world.
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1.???????? History of?Breast cancer
Breast cancer is one of the tumor cancers has been known since ancient times. The oldest description of cancer (although without using the term ?cancer?) comes from Egypt, of 1600 BC approximately.
The Edwin Smith Papyrus describes 8 cases of tumors or ulcers of cancer who were treated with cauterization, with a tool called ?orquilla of fire?. The writing says about the disease: ?There is No treatment? when the tumor is bloody, hard and infiltrating. At least one described is of a man. Also used to make descriptions in ancient Egypt and Papyrus Ebers.3 more recently Hippocrates describes several cases and says that the deep and widespread cancer patients should not be treated because they live by more tiempo.4 3
For centuries, doctors have described similar cases, all having a sad conclusion. It wasn?t until medical science achieved greater understanding of the circulatory system in 17TH century that progress was happy. In this century, the relationship between breast cancer and axillary lymph nodes could be determined. The French surgeon Jean Louis Petit (1674-1750) and later the surgeon Benjamin Bell (1749-1806) were the first to remove the lymph nodes, breast tissue and the pectoral muscles, paving the way for the modern mastectomy. Bell is the author of the most important work in this area of his time: dealt with diseases of the breast and the mamaria.4 region its path of understanding and progress was followed by William Stewart Halsted who invented the operation known as ?radical Halsted mastectomia?, procedure that has been popular until the late 1970s.
2.???????? Etymology
The name of carcinoma refers to the epithelial nature of cells that become malignant. In fact, in the strict sense, so-called breast carcinomas are adenocarcinomas, as derived from cells of glandular lineage (of glands of external secretion). However, the glands of external secretion derived from cells of epithelial lineage, so that the name of carcinoma which applies these tumors is generally accepted as correct even if she is not exact. In really rare cases there are scaly cancers of breast could be more precisely called carcinomas. These scaly tumors, true strict carcinomas, are consequence of metaplasia of cells of glandular origin.
There are malignant breast tumors are not glandular and epithelial lineage. These tumors, rare, receive other different generic names. Sarcomas are the product of the malignant transformation of cells of the connective tissue of the breast. Lymphomas are derived from lymphocytes, a type of white blood cells from the lymph nodes. In general, lymphomas are not rare tumors, but it is rare that lymphoma has their place of origin in one breast and not in other parts of the body.
3. Classification of Breast cancer
In medicine breast cancer is known with the name of carcinoma of the breast. It is a malignancy that originates in the rapid and uncontrolled proliferation of cells that dress, in 90% of cases, the inside of the ducts during breastfeeding, carrying milk from the glandular acinos, where it occurs up to galat?foros, located behind the areola and the nipple duct where accumulates waiting to go outside. This breast cancer is called ductal carcinoma. In 10% of the remaining cases the cancer has its origin in the own glandular acinos and is called lobular carcinoma. Ductal carcinoma can spread to the inside of the ductal light and invade the interior of acinos in what is known as lobular cancerizaci?n phenomenon.
Breast cancer has been classified on the basis of different schemes.
a.?Staging
The system of TNM staging for breast cancer based on the size of the tumor (T), if the tumor has spread to the lymph nodes (N), in the armpits or not has spread, and if the tumor is has metastasized (M) (i.e., if it has spread to more distant body region).5 larger tumorsnodal spread and met?stasicos have a larger number of staging and a worse prognosis.
The main staging includes: 6
- Stage 0: is a disease with positive markers or pre-maligna (sometimes called CDIS: ductal carcinoma ?in situ?).
- Stages 1-3 are defined as the ?beginning? of cancer and potentially curable.
- Stage 4 is defined as ?Advanced? stage cancer or metastatic cancer because cancer spread to other organs of the body, most often to the bones, lungs, liver, or brain and is considered incurable.
b. Pathological anatomy
The majority of breast cancers derive from the unit duct-lobulillar.7 cancer cells from other tissues are considered to be uncommon in breast cancer. The term ?Carcinoma in situ? refers to the type of cancer that is confined to the ducts or the lobules glandular, light without invade tissues vecinos.2 Furthermore, the invasive carcinoma is rampant in too much to break the so-called basement membrane and extend infiltrating the tissue surrounding the ducts and breast lobules, thus penetrating the surrounding tissue. The cells divide more quickly have a worse prognosis. A way to measure the growth of a tumor cells is the presence of the protein Ki67, indicating that the cell is in S phase of its development and also indicates susceptibility to certain treatments.
There are multiple histological types in breast cancer. Ductal carcinoma is the most common subtype. Lobular carcinoma?
c. Sensitivity to receivers
All cells have receptors on their surface, in their cytoplasm and the cell nucleus. Certain chemical messengers such as hormones bind to these receptors and this causes changes in the cell. They are three important receptors which can affect breast cancer cells: (RE) estrogen receptor, progesterone (PR) and HER2/neu receptor. Cells that have one of these receptors puts them a positive sign for this receiver and a negative sign if it is absent: ER + (positive), negative RE (RE-), RP + (positive), negative PR (PR-), HER2 + (positive) and HER2 negative (HER2-). Those cells that do not have any of these receptors are called basal or triple negative. All of these receptors are identified by electron microscopy.
Many breast cancers are sensitive to estrogen, which means that estrogen causes cancerous breast tumor to grow. This type of cancer called estrogen receptor positive cancer or RE-positive cancer. He ER breast + cancer can be treated with drugs that block the action of estrogen, such as tamoxifen. Treatment with tamoxifen for five years reduces recurrence and improves the prognosis.
Approximately 30% of patients with breast cancer have what is known as HER2.5 8 HER2 positive breast cancer refers to an oncogene that helps cells grow, divide, and repair themselves. When cells have too many copies of this gene, cells (including the cancerous) multiply more quickly. Experts think that women with HER2-positive breast cancer have a more aggressive disease, have a greater resistance to conventional treatments of chemotherapy and one higher risk of recurrence than those who do not have this type of cancer. 8
However HER2 breast + cancer respond to drugs such as the antibody monoclonal, trastuzumab ? in combination with conventional chemotherapy ? and this has improved the prognosis significativamente.8
Receiver State is used to divide the breast cancer in four molecular classes: basal ? cell and that are HER2-ER, PR ? and -(triple negative, TN). The majority of BRCA1 cancers are similar to basal TN. (2) Luminal a, are ER + and under grade B Luminal (3) are ER + but often of high grade (4) the HER2 +, which have amplified ERBB2.
Finally, State of receiver has become a critical of all breast cancers assessment that determines the suitability of the use of specific treatments, for example, tamoxifen and or trastuzumab. Now, these treatments are some of the most effective treatments of breast cancer adjuvant. On the contrary, negative breast cancer test (i.e., not positive receptors) is now thought to indicate a poor prognosis.
d. DNA Microarray
DNA chips are capable of distinguishing the normal cells of breast cancer cells, finding differences in hundreds of genes, although it is unknown the importance of most of these differences. Several screening tests are commercially available, but the evidence for their value is limited. The brand Oncotype DX is the only test supported by evidence level II, which has not been approved by the administration of food and medicines of United States (FDA), but is endorsed by the American Society of Clinical Oncology. The brand MammaPrint has been approved by the FDA, but is only compatible with level III evidence. Two other tests have level III tests: Theros and MapQuant Dx.
4. Epidemiology
Breast cancer is the most common in the Western woman malignancy and the leading cause of death from cancer in women in Europe, United States, Australia and some countries of America Latina.9
Breast cancer accounts for 31% of all cancers in women worldwide. Approximately 43% of all cases in the world in 1997 correspond to the developing of desarrollo.10 the incidence is rising in Latin America and in other regions where the risk is intermediate (Uruguay, Canada, Brazil, Argentina, Puerto Rico and Colombia) and bass (Ecuador, Costa Rica, Peru).10
Based on a statistical analysis of the most recent year for which data are available in each country, there are five countries where the annual mortality for every 10,000 females is greater: Uruguay (46.4), Trinidad and Tobago (37.2), Canada (35.1), Argentina (35.2) and United States (34.9).10
Frequency of the breast cancer in Latin America (data) 11
5. Risk factors
Today, the breast cancer, like other forms of cancer, is considered to be the result of damage to DNA. This damage comes from many known or hypothetical factors (such as exposure to ionizing radiation). Some factors such as exposure to estrogen leads to an increased range of mutation, while other factors such as BRCA1, BRCA2 and p53 oncogenes cause decreased repair of damaged cells.
Humans are not the only mammals capable of developing cancer of the Parris mama.15, 16 gatas17 and some types of mice, mainly the domestic mouse, they are likely to develop breast cancer that is suspected is caused by random insertional mutagenesis by virus (MMTV) mouse breast cancer. Suspicion of the existence of viral origin of breast cancer is controversial, and the idea is not mostly accepted by the lack of definitive or direct evidence. There is much more research in the diagnosis and treatment of cancer than in their cause of origin.
a. Age
The risk of breast cancer increases with age, but breast cancer tends to be more aggressive when it occurs in women young 15 most cases of advanced breast cancer is in women over 50 years. Women are 100 times more likely to suffer than the hombres.1 breast cancer
For a woman who lives beyond the 90 years the probability of breast cancer throughout his life is 12.5% or 1 in 8.
A type of breast cancer that occurs and is especially aggressive and disproportionate in young women is inflammatory breast cancer. Tends to be discovered in stage III or stage IV. It is also distinctive because typically not presented with mass therefore is not detected by mammography or ultrasound. It occurs with the signs and symptoms of a mastitis.
b. Genes
Approximately 5% of patients with cancer of the breast (represented in red) ?inherit? a peculiar form of genes that make you susceptible to the disease.
Although it is more frequent that are external factors that predispose a woman to breast cancer, a small percentage leads a hereditary predisposition to the disease.
Two genes, the BRCA1 and BRCA2, have been associated with a familiar shape rare cancer of mama.18 women whose families have mutations in these genes have one higher risk of developing breast cancer. Not all people who inherit mutations in these genes will develop breast cancer. Together with the characteristic of the syndrome of Li-Fraumeni p53 oncogene mutation, these mutations would determine approximately 5% of all cases of breast cancer, suggesting that the rest of the cases are sporadic. Recently found that when the BRCA1 gene is combined with the BRCA2 gene in one person, it increases your risk of breast cancer by up to 87%.19
Other genetic changes that increase the risk of breast cancer include gene mutations (Cowden syndrome) PTEN, STK11 (Peutz-Jeghers Syndrome Syndrome) and CDH1 (cadherin-E); their frequency and increased risk for breast cancer still is not known with accuracy. In more than 50% of the cases the gene associated with breast cancer is unknown heredado.18 in comparison with countries with totally Caucasian population, the prevalence of these mutations in the population of Latin America is possibly menor.18
A patient has a higher risk of breast cancer if you have a close relative who has suffered this type of cancer, uterine cancer, ovarian cancer, or colon cancer. About 20 to 30% of women with breast cancer have a family history of the enfermedad.1
c. Hormones
Exogenous estrogens, especially those used in the therapy of hormone replacement with genetic predisposition, constitute elements of greater weight in the occurrence of cancer of mama.20 many women take this type of therapy to reduce the symptoms of menopause. Has also described a slight increase in the risk of breast cancer in women taking contraceptives orales.21
The factors associated with female hormones and increased frequency of breast cancer include earliness at maturity (before age 12), menopause after age 50, the nuliparidad and the first term pregnancy achieved after the 30 or 35 years. 22 23 on the other hand, if the first menstruation occurs after age 12the menopause is before age 50, or the first pregnancy occurs before the age of 10-20 that follows the first menstruation, the risk of breast cancer is menor.24
There is no definitive conclusions on a partnership between the abortion in the first trimester of pregnancy and the subsequent risk of cancer mama.25
Epidemiological studies have suggested that a diet with a high content of Phytoestrogens, which are compounds Polyphenolic similar to estradiol and present in plants such as soybeans, cereals and other 300 vegetables and legumes, can be associated with low incidence of breast cancer, however scientific studies are still throwing conlusiones contradictoras.
However, although there is a risk of losing the ability to have children (mainly due to chemo and radiotherapy can destroy the reproductive tissues), currently exist different means of preservation of fertility, which are available at health centres to prevent this problem.
It has been suggested that environmental pollution, chemicals in deodorants, type Bras ring with rods and breast implants increase the risk of breast cancer, however, there is still scientific basis to confirm that these factors will increase the riesgo.27
Women who took diethylstilbestrol (DES) to prevent abortions may have a greater risk of breast cancer after 40 years. 28 this drug are you supplied to women between 1940 and 1960.
Obesity has been associated with breast cancer, 28 though this link is controversial. The theory is that obese women produce more estrogen, which can stimulate the development of this cancer.
If a patient received radiation therapy as a child or young adult to treat cancer of the chest area, 28 there is one greater risk of breast cancer. The younger has been to start radiation, greater the risk, especially if the radiation was given when women were developing breasts.
Discusses the influence of the liquor on the risk of cancer of mama.28 should however be emphasis than women who do not have any known risk factor can develop breast cancer, which is why the absence of risk factors must not lead to a false sense of security.
6.???????? Clinical picture
The main reason for consultation in relation to the breast of a woman is the detection of a mass or lump. Approximately 90% of all the mammary masses are caused by benign lesions. That they are soft and elastic masses are usually associated with a fibroadenoma in women 20 to 30 years of age, and cysts in women between 30 and 40 years 29 30 malignant breast masses are characterized by solitary, not very notorious, harsh and painful to palpation.
Another frequent manifestation is breast pain. This rare mastalgia time is associated with breast cancer and is usually related to fibrocystic changes in female premenopausal. 31 postmenopausal women receiving estrogen replacement therapy may also complain of pain in the sinuses caused by changes fibrocystic. 32 pain from fibrocystic disorders often seen accompanied by diffuse small lumps in the breast.
Early breast cancer usually does not cause symptoms; reason why regular breast exams are important. As the cancer grows, symptoms may include redness, swelling, and retraction of the skin or the nipple with the appearance of holes or fruncimiento that looks like orange peel. Another common problem is the discharge from the nipple. The flow of a carcinoma of the breast is usually spontaneous, with blood, associated with a mass and located in a single duct in one breast. In some cases the secretion of fluid coming from the nipple can be clear to yellowish or greenish color, and look like pus.
Lumps or growths in the armpits which are hard, have jagged edges and usually painless. Change in the size, shape or texture of the breast or nipple. Men can also get breast cancer and symptoms include breast lump, as well as pain and breast tenderness.
Advanced breast cancer symptoms may include:
- Bone pain.
- Pain or discomfort in your breasts.
- Skin ulcers.
- Swelling of an arm (next to the breast with cancer).
- Weight loss.
We must emphasize that breast cancer can manifest as an asymptomatic lesions and that when there?s retraction of the skin is an advanced cancer, so to detect a mass, the patient should seek professional help and ask for an accurate diagnosis based on studies and not in clinical presumption.
7.???????? Diagnosis
Breast examination must be in an upright position, sitting and lying down with the hands of the woman behind the head. The breasts should be inspected looking for differences in size, retraction of the skin or nipple, prominent venous patterns and signs of inflammation. Use the surface flat of the fingertips to palpate the breast tissue against the chest wall. Axillary and supraclaviculares areas must be reviewed in search of nodules. The nipple should be compressed gently to check for secretions.
8.???????? Mammography
The extension of the use of mammography has been effective, as it has reduced breast cancer mortality rates up to 30%.33 mammography is the best method of early injury screening available. The survival rate for women with breast cancer increases dramatically when diagnosed at an early stage, detected early is a survival at age 10 that achieves up to 98% 34 unfortunately, only 60% of cancers are diagnosed in a localized stage. So the mammography regular must be accompanied by a physical exam regular breast to improve that percentage.
Recommended mammography every year for asymptomatic women over the age of 40 years. 35 is known as detection, despistaje or ?screening? mammography uses a protocol of two projections, usually one in medial lateral oblique direction and craneocaudal, i.e. from top projection abajo.36 mammograms in symptomatic women or in those with high risk factors is known as diagnostic mammogram and they generally use more than two projections by imagen.36
The pesquistaje in 50 to 75 years of age women significantly decreases the mortality rate from breast cancer. Screening in women aged 40 to 49 years is controversial, because of a lower incidence of the disease in this age group and that the breasts are denser which decreases the sensitivity of mammography. Several studies show a significant reduction in mortality rates in women of this age group who received mammograms, while other work showed no benefits in this group etario.34
There is the possibility of obtaining false positive with mammograms. Women aged between 40 and 69 years have a probability of 30% of false positives on their mammogram during a period of 10 years. These false positives lead to complementary tests, follow-up and biopsies, increased costs and unnecessary anxiety, psychological consequences may persist even after a benign outcome. The frequency of false positive is greater for younger women because the majority of the masses in their midst are usually benignos.34
Ultrasound
The pesquistaje ultrasound is useful to differentiate between mass or solid breast tumors and cysts, essentially when a palpable mass is not well displayed in a mammography. 37 ultrasound is especially useful in young women with dense breast tissue with a palpable mass that is not displayed in a mammogram. Ultrasound must not be used during routine checks, especially because the microcalcificaciones are not displayed and detection of carcinomas is insignificant with ultrasound.
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