2 Cancer Case Studies/ patho 404 – Flashcards
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Is colon cancer an inherited disease? Is colon cancer a genetic disease? Explain the distinction between "inherited" and "genetic".
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it can be, not always, mutations needs for to occur, some cancers are inherited requires genetic mutation, people can inherit a recessive mutate tumor suppressor gene, but it still requires some sort genetic transformation to occur in germ line
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Define each of the following genes and their distinctions, then explain how each type of gene can participate in the pathogenesis of cancer: tumor suppressor gene; oncogene; and, DNA repair genes.
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Tumor suppressor gene-normally suppressor tumors, pRB, P53, recessive trait, loss of function mutation Oncogene-as mutated this can change characteristics of growth factors and receptors. dominant gene. Helps with proliferation DNA repair gene-multi step, genes normally encode enzymes that can proof read, when we lose their effectiveness increased changes of cancer
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For hereditary colorectal cancer, several distinct genetic events are required and inheritance of a single altered gene can result in a significant predisposition to colorectal cancer in two different syndromes—familial adenomatous polyposis (FAP), and hereditary nonpolyposis colorectal cancer (HNPCC). Identify the genetic defect inherited in each of these syndromes (FAP and HNPCC) with regard to tumor suppressor genes, oncogenes or DNA repair genes, and explain how this defect contributes to cancer pathophysiology.
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FAP-multiple genetic mutations have to occur Deletion of "adenomatous polyposis coli" APC tumor suppressor gene Deletion of second APC allele Mutation of "RAS" oncogene Loss of both alleles of "deleted in colon cancer" DCC, tumor suppressor gene Loss of p53 tumor suppressor gene And then more changes lead to invasion and metastasis HNPCC-hereditary nonpolyposis colon cancer Colon cancer-arises from DNA repair genes Several additional step-wise mutations are required in both oncogenes and tumor suppressor genes to give rise to damaged DNA repair genes
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Colorectal cancer typifies the multistep nature of cancer and involves progression from a benign adenoma to a malignant carcinoma, which has the potential to metastasize to the secondary sites such as the liver. Briefly describe the genetic events that are part of this process. Discuss the significance of some of the signs and symptoms associated with colon cancer observed in our patient: A. What is the significance of black stools and blood in the stool of our patient? B. What does hemoglobin levels reflect and why is his hemoglobin low? C. Why is he fatigued? D. Why has he lost weight?
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collect loss of time form mutation, more normal to more malignant increase proliferation, easier for invasion and eventually metastasis A. black stool-blood in stool, damage to blood vessel, colon cancer, increase in constipation, and pain, tumor has eroded and made open a blood supply B. hemoglobin levels are going down, some evidence of blood loss c. less blood, less oxygen carrying capacity, less ATP, hence tired d. may not feel like eating, obstruction or damage to gi system so you aren't absorbing nutrients cachexia process
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Discuss how colon cancer is diagnosed in this patient: A. What does a colonoscopy reveal? B. Why is a tissue biopsy done and what does this reveal about the status of cancer in general?
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diagnose early, as we get older risk increases A- status of intestine, polyps B- reveals cellular changes associated with cancer, arrangement, demarcation,
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Discuss the treatment for colon cancer: A. What are the general advantages and disadvantages to surgical removal of cancers versus use of cancer chemotherapy? When would each of these approaches be used? B. Justify the surgical approach taken with this patient. Why were additional tissue and lymph nodes removed? How would his treatment be different if his lymph nodes were involved? How would this alter his prognosis?
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A--surgery-if localized, removed lesion, chemo-if spread, increase risk of a poorer outcome B-localization required, demarcation, invasion could have occured, need to make sure prevent any more cancer from developing
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Screening for colon cancer may be done in individuals, such as the elderly, who may be at greater risk than the average member of the population for colon cancer. Describe two general types of screening tests that are utilized—a fecal occult blood test (FOBT); and a sigmoidoscopy or colonoscopy. Describe each test and explain what the primary care provider looking for with each of these tests?
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fecal occult blood test-looks for blood in your poop, or feces. It can be a sign of a problem in your digestive system, such as a growth, or polyp, or cancer in the colon or rectum. colonoscopy- uses a thin flexible camera, check for normal tissue, may biopsy polyps
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What is CEA and what is usefulness in terms of diagnosis or treatment of colon cancer? Why will it be measured again in the future?
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carcinoembryonic antigen monitoring, follow up see progression and change in CEA levels indicates how cancer is responding to treatment
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What is retinoblastoma and what is the pattern of inheritance for this type of cancer?
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rare, childhood cancer, recessive trait, but inherited in a dominant fashion if you inherit one copy from your parent, at risk of getting the second mutation 90%-penetrance pRB mutated tumor suppressor gene, no longer have break in cell cycle, promotes proliferation more chance of other cancer
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What type of gene is the retinoblastoma gene and how does mutation in this gene give rise to cancer? Be sure to indicate the consequences of mutating one or both of the alleles for this gene.
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recessive, pBR gene, mutated tumor suppressor gene one gene-90% both gene- 100%?
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What is the difference between a germline and a somatic mutation?
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germ line-genetic somatic-develop mutation
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What is the frequency of retinoblastoma due to germline mutation and what is the frequency of retinoblastoma due to somatic mutation?
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can be germ line, 40% somatic mutation -60%
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What is the frequency of unilateral and bilateral retinoblastoma? How does this related to whether the mutation is germline or somatic?
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90%, greater risk for both eyes in germ line mutation than somatic, typically under age 1 genetic, somatic occurs under age 5
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What is the normal function of the pRB protein with regard to cell cycle regualation?
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provides a pause in cell cycle
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What is the consequence of mutation in the RB1 gene in terms of regulating the cell cycle and how does this contribute to cancer?
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continue to proliferate, cell division is unregualted
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What are general changes related to changes in cell growth or proliferation that are characteristic of cancer?
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increase growth factor and changes to recpetors
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Describe the relationship between cigarette smoking and lung cancer in terms of risk, and in terms of pathophysiological processes that are related to smoking. Can you reduce your risk of lung cancer by stopping smoking before developing lung cancer? Explain.
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85% lung cancer attributed to smoking carcinogens, promote mutations smoking initiates lung cancer, continued use promotes some cases injury is reversible, if mutation has occurred cancer can develope
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What is the risk for individuals exposed to second-hand smoke? What are other exposures that are associated with lung cancer?
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Secondhand smoke causes numerous health problems in infants and children, including more frequent and severe asthma attacks, respiratory infections, ear infections, and sudden infant death syndrome (SIDS) radon gas, arsenic
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How does his S/S of coughing up blood, weight loss and SOB relate to lung cancer?
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eroded to a blood vessel cachexia, lack of appetite, etc lung function, block airways inflammation of fluids
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Describe the initiation, promotion, progression theory of carcinogenesis, and describe how this theory relates to lung cancer.
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smoking initiates cells can return to normal, may take about 5 years carcinogens promotes more cancer-promotions stage
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Describe the pathogenesis of lung cancer in terms of oncogene and tumor suppressor genes.
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evidence that both are involved these mutation allow tumor to grow and then proliferate
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Identify the two major types of lung cancer. Which of these types is most likely associated with cigarette smoking?
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non small carcinomas small lung carcinoma- more rare paracarginogenic, oat cell, highly malignant, rarely resectable
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Which of these types of cancer may be associated with syndrome of inappropriate ADH secretion (SIADH)? Explain the relationship between lung cancer and SIADH for this type of lung cancer.
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small cell lung carcinomas, starts turing on ADH due to being less differentiated activate changes in calcium lvl, ACTH ADH secretion, more primitive, opposite of differentiated and turn on ectopic sources develop a cushins like disorder, moon face, fat pads,
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Describe lung cancer staging and treatment options for lung cancer. What is the prognosis for various types of lung cancer?
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localized, surgically more often radiation on lungs spread and metastasis-chemo
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Define chronic myeloid leukemia (CML) and identify which cells are affected?
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a type of leukemia, myeloid linage cell from stem cell, produce things like platelet, erythrocytes, white blood cells, myloid cover lots of different cells results in over growth of certain cell populations
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Describe is the relationship between S/S of fatigue, fever, and pain and CML.
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bone marrow- pain, glass or newly formed cells RBC-fatigue WBC-infection, fever other bleeding disorders
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How is CML diagnosed?
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blood test, look in chromosomal make up polymerase chain reaction
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What is the Philadelphia chromosome?
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translocation from 9-22
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How is the Philadelphia formed and how does it relate to cancer? Specifically which genes are affected by the formation of this chromosome?
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translocation of genetic material between chromosome 9 and chromosome 22, contains a fusion gene called BCR-ABL1. This gene is the ABL1 gene of chromosome 9 juxtaposed onto the BCR gene of chromosome 22, coding for a hybrid protein: tyrosine kinase signaling protein that is "always on", causing the cell to divide uncontrollably.
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How is this chromosome identified (i.e. what kinds of tests can be done to observe this genetic mutation associated with CML)?
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karyotype
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Describe the characteristics of each of the three phases of CML?
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Chronic Phase- Accelerated Phase- Blastic Phase-
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Chronic Phase
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The chronic phase is when the leukaemia is most stable and still developing slowly. About 9 out of 10 people (90%) are in chronic phase when they are diagnosed. Some people are diagnosed by chance and have no symptoms. But you may have symptoms that are mild and vague. You may feel tired and lose a little weight. Your spleen may be slightly enlarged. The number of white cells in your blood may be raised and so may the number of platelets. Fewer than 1 in 10 (10%) of the blood cells in your bone marrow are immature white blood cells known as blasts. Read more at http://www.cancerresearchuk.org/about-cancer/type/cml/treatment/staging-for-chronic-myeloid-leukaemia#gKxlQiEsLFHsIJDE.99
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Accelerated Phase
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In the accelerated phase, you have more obvious symptoms. You may notice that you feel more tired than usual. You may lose weight. Your spleen may be enlarged, which might give you an uncomfortable or painful feeling to the left of your stomach, under your ribs. Between 10% and 30% of the blood cells in your bone marrow are immature blasts. Read more at http://www.cancerresearchuk.org/about-cancer/type/cml/treatment/staging-for-chronic-myeloid-leukaemia#gKxlQiEsLFHsIJDE.99
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Blastic Phase
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Targeted therapy with a tyrosine kinase inhibitor. Chemotherapy using one or more drugs. High-dose chemotherapy. Donor stem cell transplant. Chemotherapy as palliative therapy to relieve symptoms and improve quality of life. A clinical trial of a new treatment.
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What are the treatment options for CML? Specifically describe new medications that act as tyrosine-kinase inhibitors and how they work.
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tyrosine kinase inhibitors, really effective against CML, 95%, has to keep taking resistence and refactorieness? some people this doenst work, bone marrow transplant follows
