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home / study / science / biology / biology questions and answers / a 55-year-old postmenopausal, retired school teacher, with a family history of breast cancerin ... Question: A 55-year-old postmenopausal, retired school teacher, with a family history of breast cancerin he... A 55-year-old postmenopausal, retired school teacher, with a family history of breast cancerin her mother and sister, noticed a painless hard lump in the upper-outer quadrant of theright breast. A history and physical exam were followed by a mammogram that identified a1cm lump in the right breast. She chose a breast conserving treatment consisting of localizedsurgery called a lumpectomy to remove what turned out to be an adenocarcinoma of thebreast, followed by removal of some of the axillary lymph nodes. She was started onTamoxifen, a drug that acts as an anti-estrogen toward breast cancers, but has estrogenicaffects on certain other tissues such as the endometrium. This individual has two daughters,ages 35 and 37 who were strongly encouraged to have yearly physicals and mammogramsby their mother's doctor, and to perform monthly self breast exams. 1. What is the function of lymph nodes? 2. What problem could develop in the arm as a result of removing the axillary lymph nodes? 3. What histologic changes would you expect in the lining of the uterus if Tamoxifen hasestrogenic effects on the endometrium? 4. What role do progesterones have on the uterus in the normal menstrual cycle? 5. What uterine symptoms might this postmenopausal woman develop while takingunopposed continuous estrogens (no progesterone)? 6. What is BRCA 1 and 2? 7. Why might genetic counseling be of value for this
Explanation / Answer
1. Function of lymph nodes: Lymph nodes act as filters to separate bacteria and toxic substances from the lymph. The main functions of lymph nodes are:
2. Problems involved in Removal of axillary lymph nodes: The removal of axillary lymph nodes may lead to irreversible lymphedema in the arm. As seen in the discussion of question no.1, the fluid absorption and movement of lymph through lymph node does not occur when lymph node is removed, thus causing lymphedema
3. Effects of Tamoxifen estrogenic effect on endometrium of uterus: The estrogenic effect of Tamoxifen leads to following changes in uterus:
Other common side effects of Tamoxifen includes: Hot flushes, vomiting, vag_inal bleeding, va_ginal discharge, menstrual irregularities (In premenopausal women), venous thromboembolism, dermatitis, anorexia, depression, mild leucopeniaa, ocular changes
4. Role of Progesterones on the uterus in the normal menstrual cycle: Progesterone promotes the secretory activities of uterine endometrium during the secretory phase of the menstrual cycle which makes the uterus ready for implantation of the fertilized ovum
5. Symptoms while taking only estrogens and no progesterone in postmenopausal woman: Result in thromboembolic events, leads to development of breast cancer, nausea, edema, breast tenderness and increases the risk for Uterine cancer. Hence, only estrogen without progesterone is used for women who had Hysterectomy
6. BRCA1 and BRCA2: These are genes whose mutation accounts for about 5-7% breast cancer cases. These are autosomal dominant genes which are partially penetrant and present on chromosome 17q (BRCA1) and 13q (BRCA2). These are tumor suppressor genes and mutation of these genes results in tumorigenesis. The role of these genes in cell cycle are: DNA repair, Cell cycle checkpoint control, Ubiquitylation, Transcriptional regulation. DNA damage activates the BRCA genes.
7. Genetic counselling value for this condition: BRCA mutation as seen above are responsible for 50% of the hereditary breast cancers. DNA sequencing reports are used for genetic counselling as there is about 10-13% risk of breast cancer when there is a positive family history. Positive BRCA1 or 2 indicates that there is 50-85% risk of breast cancer. Individual from a family with mutation of BRCA genes, Individuals with breast cancer under 45 years or under 50 years whose relative had ovarian cancer, 2 relatives with breast cancer, relative with male breast cancer, high risk ethnic group (African-American), history of epithelial ovarian cancer, etc serves as a criteria for genetic counselling for BRCA1/2 breast cancer.
As there is 50-85% risk associated with these genes, genetic counselling serves as a very valuable source of early detection, prevention and treatment.
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