Hormonal Influences on Breast Tissue during the Normal Menstrual Cycle - Essay Example

Breast MRI Presented by Name Presented To Lecturer Institution Topic Date Breast MRI Q 1 Hormonal influences on breast tissue during the normal menstrual cycle: Breast tissue is a complicated arrangement of tissues that are closely tied to blood vessels, fatty tissues and nerves. These tissues are built in the mammary glands. There are two hormones that are produced by the ovary which have influence on the breast tissue during the menstrual cycle, oestrogen and progesterone. When monthly cycle starts the level of blood oestrogen do rise. The rise of oestrogen causes the breast ducts and breast lobules to enlarge. Once ovulation has taken place, corpus lateum starts to produce progesterone hormone. The progesterone produced causes further changes in the breasts whereby tenderness as well as heaviness of the breasts occurs. This is as a result of high level of progesterone in the body which results to more blood flow in the breast. If one does not get pregnant, oestrogen and progesterone hormone levels starts to fall. This causes breast lobules and ducts to regress, making the breast to lose tenderness and they stop swelling. This is the onset of menstruation (Morrow and Jordan 2003). Breast MRI: MRI (Magnetic resonance imaging) is test which uses magnetic field pulses and radio wave energy to make pictures of structures and organs in the body. It reveals the occurrence of problems such as tumours, injury, bleeding, infection or blood vessel diseases. Breast MRI is a clinical management method that is used to screen for breast cancer mostly in pre-menopausal women. MRI uses radio and magnetic waves to produce detailed images of the breasts, which are three-dimensional. To identify an abnormal area in a better way, patient is injected intravenously with a contrast solution called gadolinium during the MRI. Gadolinium collects in regions with cancer growth and shows up as white areas on background of MRI images, which is dark, an indication of cancerous cells. It is of great important to know how hormones influence the breast tissue when scheduling the breast MRI. The level of hormones in the body has a major impact on the accuracy of breast MRI. When the level of progesterone in the body is high, more blood tends to flow into the breast. As a result contrast solution (gadolinium) tends to collect all over the breast making it hard to differentiate the normal and the abnormal tissue. This can lead to false positive results. In addition, it can make the MRI to be repeated again leading to wastage of time and resources (Morrow and Jordan 2003).Women with normal menstrual cycles have progesterone levels that are lower during the first half of their menstrual cycle. This is usually the best time to do a breast MRI. First half of normal menstrual cycle should be counted from the first day of one menstruation to the first day of the next menstruation. This helps to get perfect results and to avoid repeating the process. According to (Ellis 2009) it is difficult to figure out when to do breast MRI in women with irregular menstrual cycle. Hormonal fluctuations in such women affect gadolinium uptake in the breast tissue, and this make interpretation of MRI findings very hard, a condition that can result to false positive results. Q 2: BRCA 1 and BRCA 2 genes: In simple terms, BRCA stands for breast cancer susceptibility. BRCA 1 means breast cancer susceptibility gene 1 while BRCA 2 means breast cancer susceptibility gene 2. BRCA 1: This is a caretaking gene in the human body that has the role of producing Breast cancer type1. Breast cancer type 1 is a protein that repairs damaged (deoxyribonucleic acid) DNA. Generally, BRCA1 is expressed in the cells of various tissues among them being the breast cells where it helps in repairing DNA that is damaged. On the same note, BRCA 1 also destroys cells containing damaged DNA if the DNA is not repairable. In some instances, BRCA1 damages so that it does not perform its roles properly or fails to perform at all. In such instances, repair of damaged DNA does not occur properly and this leads to increased risk of cancer (Ellis 2011). BRCA 1 belongs to the family of genes known as tumor suppressor genes. To perform its roles, BRCA1 regulates cell division process whereby it manages the rate at which cell division takes place and their growth rate. This gene therefore prevents random cell division and growth bursts that would lead to development of abnormal tissue. This is in turn harmful as it can threaten the health of an individual. According to Ellis (2011), BRCA 1 contains 22 coding exons and 2non- coding exons and occupies a region of the chromosome equal to 100-kb. Exon 11 is large compared to the others and contains more than half of the coding region of BRCA 1 gene. Every BRCA 1 gene contains an amino-terminal finger RING domain, an SQ cluster domain (SCD), a carboxy-terminal C-terminal (BRCT) and domains having multiple functions and that are associated with binding proteins. It is the interaction between the N-terminal ring domain and BARD1 (protein-1 that is associated with ring complex) that mediates the activity of ubiquitin legase. This activity is of paramount importance in tumor suppression. BRCA 2: Like BRCA 1, BRCA 2 is a tumor suppressor gene that is responsible for repairing damaged DNA. The structure of BRCA 2 is however very different from that of BRCA 1. This gene repairs damaged DNA by binding with and regulating the protein produced by RAD51. This binding fixes broken DNA, which in turn helps in maintaining stable genome. Otherwise, there could be dangerous gene arrangements, which can end up into hematological cancers. This is especially important for repairing double-strand breaks during mitotic and meiotic recombination. In addition, BRCA 2 is associated with Proliferating Nuclear Cell Antigen (PNCA). This, according to Ellis (2011), takes part in repairing of DNA as well as in DNA replication. BRCA 2 gene is usually located on chromosome 13q12-13. It covers a region of about 70 kb the DNA. 26 coding exons are contained within the 11.2-kb coding region. These then encodes a protein that comprises of 3,418 amino acids (Ellis 2011). Ellis (2011) further points out that BRCA 2 gene does not bear any similarity to BRCA 1 and that the protein does not have functional domains as those found in BRCA 1. BRCA gene mutation: It is worth noting that mutations occur in BRCA 1 as well as in BRCA 2. However, not all mutations are harmful. While some mutations are harmful, some are neutral and others are harmless. Harmful mutations often increase the risk of individual developing diseases such as cancer (Thompson and Easton 2002). For instance, risk of breast or ovarian cancer among women increases if there are harmful mutations of BRCA 1 and BRCA 2. According to Ellis (2011), such risks of ovarian and/or breast cancer are high at early ages mostly before menopause and mostly if such a woman has close members of her family, who have been diagnosed with ovarian/breast cancer. Thompson and Easton (2002) also points out that harmful mutation of BRCA 1 and BRCA 2 lead to risks of developing cancer of the cervix, uterine, pancreas and colon. More so is when an individual has harmful mutations of BRCA 2 since such an individual has increased risks of developing pancreatic, gallbladder, stomach and bile duct cancer as well as melanoma. In men, harmful mutations of BRCA 1 increase the risk of developing breast cancer as well as cancer of the testicles. In addition, such men are usually at higher risks of having an early onset of prostate cancer. Clinical management of patients with harmful mutations of BRCA: There are various methods and means of managing risks of cancers in patients with harmful mutations of BRCA 1 and BRCA 2. Surveillance or cancer screening is one of the clinical management methods of managing harmful mutations of BRCA 1. Surveillance involves detecting the cancer at an early stage so that it is treated. However, Palma et al. (2006) point out that screening does not eliminate the risks of developing cancer. Surveillance methods for breast cancer include mammography as well as clinical breast exams. Surveillance for ovarian cancer includes clinical exams, testing blood for CA-125 antigen and transvaginal ultrasound. The second clinical management method for people with harmful BRCA mutations involves prophylactic surgery. This surgical management procedure involves removing much or all the tissue that is at risk of developing cancer. This in turn reduces the risks of developing cancer. This however does not guarantee reduction in risks of developing cancer since not all tissues can be removed (Palma et al. 2006). Chemoprevention is another clinical method of managing patients with harmful BRCA gene mutations. This involves use of substances (natural or synthetic) to reduce the risk of developing cancer or reduce chances of re-occurrence (Palma et al. 2006). Q 3: Breast Implant: Breast implant is a prosthesis used to change the form, size and feel of breasts of a woman. It also corrects chest wall congenital deformities. In addition, breast implant is done in post-mastectomy breast reconstruction and for aesthetic enhancement (breast augmentation). Types of breast implant devices: Defining by filler material, there are three types of breast implant devices. These include: i. Saline implant- made of elastomer silicone shell filled with sterile saline solution. ii. Silicone implant- made of elastomer silicone shell filled with viscous silicone gel. iii. Alternative composition implant: has featured fillers like soy oil and polypropylene string. Use of MRI to assess breast implant integrity: In symptomatic patients noncontrast MRI (Magnetic resonance imaging) plays a big role in assessing the implant integrity by detecting breast implant failures. It also illustrates the spectrum of appearance of normal silicone-gel-implant and implant ruptures.MRI has high specificity and sensitivity for implant rupture. This is because it has sequences, which can emphasize or suppress signal from silicone. It can also differentiate extra capsular from intra capsular rupture, and it can assess extent of silicone leakage into granuloma and parenchyma formation in the breast. MRI reveals collapsed intra capsular rupture reliably. This is by detecting fragments of shell floating in the silicone gel implant Intra capsular and extra capsular rupture and their appearance in MRI: Rupture of breast implant is a common complication especially in silicone gel implants. It can occur spontaneously or trauma can cause it. Silicone elastomer shell, which surrounds the implants do weaken with age. Weakening is severe at edges of implant, in areas where radius of curvature is smallest and at apex of radial folds. Silicone gel implant ruptures include extracapsular, intracapsular, or combined extracapsular and intracapsular. The most common ruptures are the intracapsular. Intracapsular ruptures occur because of rupture of the shell and when silicone gels, which leak out of implant, remain confined in the peri-implant fibrous capsule. Degree of leakage of this gel from shell to intracapsular space varies a lot. In some mild cases, the degree of shell collapse and the extravasation amount can be minimal. In severe cases, all silicone gel escapes from shell into intracapsular space with the shell collapsing completely. Extracapsular rupture results from rupture of both the shell and the fibrous capsule. The extravasated silicone gel extends to the breast tissue in the surrounding instead of remaining confined in the intracapsular space. According to Stavros, Rapp and Parker (2004) intracapsular ruptures precede all the extracapsular ruptures. Extravasated silicone gel can escape directly from the implant through a rent that co-exists in fibrous capsule into breast tissue that is in the surrounding. This can be in large amounts to detect and fail to accumulate within the capsule. Extravasated extracapsular silicone consequently incites intense inflammatory response of foreign body leading to formation of silicone granuroma, which is tender and palpable. Intracapsular ruptures rarely incite this condition (Stavros, Rapp and Parker 2004). MRI appearance of intracapsular rupture is as follows; the collapsed and ruptured implants appear as serpentine bands that are fine and linear. These appear in hyper-intense silicone gel, normally known as linguini sign. MRI appearance of extracapsular rupture is as follows; MRI detects extracapsular silicone protruding outside the fibrous capsule. A linguini sign and teardrop sign can also be noted in the implant (Stavros, Rapp and Parker 2004). References Ellis, N, 2011. Inherited Cancer Syndromes: Current Clinical Management. London: Springer Science + Business Media, LLC. Ellis, R, 2009. Optimal Timing of Breast MRI Examinations for Premenopausal Women who do not have a Normal Menstrual Cycle, American Journal of Roentgenology. Volume 193, Pages 1738-1740. Morrow, M & Jordan, C, 2003. Managing Breast Cancer Risk. Hamilton, Ontario: BC Decker Inc. Page 125. Palma et al., 2006. BRCA1 and BRCA2: The Genetic Testing and the Current Management Options for Mutation Carriers. Critical Reviews in Oncology/Hematology. 57(1), Pages 1–23.  Stavros, T, Rapp, L & Parker, S, 2004. Breast Ultrasound. Philadelphia: Lippincott Williams & Wilkins. Pages 176-177. Thompson, D, & Easton, D, 2002. The Breast Cancer Linkage Consortium. Cancer incidence in BRCA1 Mutation Carriers. Journal of the National Cancer Institute. 94 (18). Page 1358–1365.  Read More