NSG 533 – Oncogenesis Exam Questions With Correct Answers

NSG 533 – Oncogenesis Exam Questions With Correct Answers Inherited forms of cancer are __________ mutations are thought to account for approximately _______% of all adult cancers - CORRECT ANSWERS germ line 5-10% Hereditary diffuse gastric cancer (HDGC) susceptibility syndrome involves germ line mutations in which gene? What does it encode? - CORRECT ANSWERS CDH1 gene that encodes the protein E-cadherin Hereditary breast & ovarian cancer is more common in which ethnic group? - CORRECT ANSWERS More common in people of Ashkenazi Jewish decent Women with hereditary breast & ovarian cancer (HBOC) syndrome have a germ line mutation in which gene? - CORRECT ANSWERS Either BRCA1 or BRCA2 Approximately what percent of gastic cancers involves germ line mutations in CDH1 gene? - CORRECT ANSWERS Approximately 3 % of all gastric cancers Life time risk of developing breast & ovarian cancer is up to _____% (breast) and _____% (ovarian). - CORRECT ANSWERS 85% 40% HNPCC (Hereditary non-polyposis colorectal cancer), also known as Lynch Syndrome, comes from a mutation in several genes involved in what function? - CORRECT ANSWERS DNA repair Hallmarks of hereditary cancers (5): EMBRA - CORRECT ANSWERS - Early age on onset: 40 - 50 years for adult onset cancers - Multiple primary cancers in a single individual: (breast & ovarian) - Bilateral cancers in paired organs (breast, kidney) - Rare presentations of cancer (male with breast cancer) - Abnormalities known to be linked with ↑ cancer risk—atypical nevi & risk of melanoma What is one of the most common types of hereditary cancer? - CORRECT ANSWERS Breast and ovarian cancer Familial cancers suggest a clustering of cancers that likely occurred by chance. How is this explained? - CORRECT ANSWERS There may be a combination of genetic and non-genetic (i.e., environmental) factors that contributed to the development of cancers within a family. i.e. smoking, obesity True or False. In familial cancer, an alteration in a single major gene is typically identified. - CORRECT ANSWERS False. In familial cancer, an alteration in a single major gene is unlikely or not identified What are four examples of environmental factors that may influence cancer risk? - CORRECT ANSWERS Diet, lifestyle, sun exposure, hormonal responses What are the three defining characteristics of cancer cells? - CORRECT ANSWERS Dysregulated growth - this factor alone does not cause malignancy; ability to invade and metastasize are of equal pathophysiologic importance Capacity for local invasion Metastasis Up to ____% of cancers are linked to environmental factors. - CORRECT ANSWERS 90% Bening tumor or malignant tumor? Slow growth - CORRECT ANSWERS Benign tumor Which population is particularly at risk in developing cancer related to immunologic factors? - CORRECT ANSWERS Kidney transplants - greater risk of developing cancer after having a transplant and having been on long-term immunosuppression. Bening tumor or malignant tumor? Defined capsule - CORRECT ANSWERS Benign tumor Bening tumor or malignant tumor? Not invasive - CORRECT ANSWERS Benign tumor Bening tumor or malignant tumor? Well differentiated - resembles tissue from which they arose - CORRECT ANSWERS Benign tumor Bening tumor or malignant tumor? Low mitotic index (few dividing cells) - CORRECT ANSWERS Benign tumor Bening tumor or malignant tumor? Do not metastasize - CORRECT ANSWERS Benign tumor Bening tumor or malignant tumor? Metastasize - CORRECT ANSWERS Malignant tumor Bening tumor or malignant tumor? Rapid uncontrolled growth - CORRECT ANSWERS Malignant tumor Bening tumor or malignant tumor? Not encapsulated - CORRECT ANSWERS Malignant tumor Bening tumor or malignant tumor? Invasive - CORRECT ANSWERS Malignant tumor Bening tumor or malignant tumor? Poorly differentiated - May not be able to determine tissue of origin - CORRECT ANSWERS Malignant tumor Bening tumor or malignant tumor? High mitotic index (Many dividing cells) - CORRECT ANSWERS Malignant tumor What are three cytological changes seen in cancer cells? - CORRECT ANSWERS Increased size and number of nucleoli due to increased activity of tumor cells Increased nuclear/cytoplasmic ratio—larger nucleus reflects increased activity and/or more genetic information Altered cytoskeleton—changes contribute to increased motility & variable sizes and shape (pleomorphism What are six aspects of altered cell growth in cancer cells? DRILLL - CORRECT ANSWERS Immortality—cancer cells proliferate indefinitely Loss of contact inhibition Decreased requirement for serum, suggesting autonomous synthesis & secretion of growth factors Loss of anchorage-dependent growth—cancer cells grow in soft agar Loss of cell cycle control—cancer cells do not progress normally through cell cycle pathways & checkpoints Reduced apoptosis—cancer cells are less susceptible to programmed cell death Changes in the cell membrane with cancer - CORRECT ANSWERS New surface antigens—cancer and transformed cells exhibit new molecules on the surface New or altered glycoproteins—transformed cells have profound changes in glycoproteins New or altered glycolipids—content and complexity of glycolipids are reduced in transformed cells In the late dissemination model, the development of metastatic tumors occurs where? - CORRECT ANSWERS Evolution of malignant cells inside primary lesion Tumor develops metastatic cell that migrates and develops into another tumor In the early dissemination model, the development of metastatic tumors occurs where? - CORRECT ANSWERS Evolution of malignant cells outside primary lesion Precancerous cell develops into metastatic cell that migrates and develops into another tumor and while precancerous cell turns into primary tumor True or false. Asingle mutation can transform a healthy cell into a cancer cell - CORRECT ANSWERS False. In order for cancer to develop, changes in chromosome structure or number and gene mutations must occur What is translocation of genes? Give one example. - CORRECT ANSWERS The exchange of genetic material from one chromosome to another Example CML-translocation between chromosomes 9 and 22 What is deletion of a gene? Give one example. - CORRECT ANSWERS The loss of DNA from chromosome Example - Retinoblastoma: segment of DNA on chromosome 13 is deleted What is inversions of genes? - CORRECT ANSWERS Segment of DNA reversed within a chromosome Change in chromosome number - CORRECT ANSWERS Entire chromosomes may be gained or lost (aneuploidy); e.g., breast cancer trisomy (extra copy) of 7, 8, 18, and 20 may occur her2/neu is associated with which types of cancer? - CORRECT ANSWERS breast, ovarian, gastric Ras proteins are associated with which type of cancer? - CORRECT ANSWERS Lung, colon, pancreatic, leukemia Point mutations are associated with what type of oncogene? - CORRECT ANSWERS Ras family Chronic myelogenous leukemia (CML) occurs from a translocation in which gene? - CORRECT ANSWERS BCR-ABL reciprocal translocation between chromosome 9 (gain) and 22 (loss) found in 95% of pts with CML; referred to as "Philadelphia" chromosome TSG normally acts to do what? - CORRECT ANSWERS Slow the growth of cells; referred to as anti-oncogene; What happens if a TSG is mutated? - CORRECT ANSWERS The gene becomes inactivated, causing excessive cell proliferation leading to cancer. Think of a TSG as the brakes of a car; when mutated, the brakes fail and the car is out of control What is the function of the pRB gene? - CORRECT ANSWERS To regulate the progression of cells through the G1 to S phase of the cell cycle; important gatekeeper of cell cycle What is the most important gene that regulates apoptosis - CORRECT ANSWERS p53