Question | Answer |
What makes a tumour benign? | It's slow growing and is contained in a fibrous capsule (so it will not metastasize) |
Where do carcinomas originate? | Epithelial cells |
Where do leukemias develop? | In blood-forming tissues such as bone marrow |
Where do sarcomas originate? | In bone and other connective tissues |
What percentage of cancers are hereditary? | 5-10% (but cancer is always a genetic disease) |
What is an oncogene? | A gene that causes cell division to accelerate out of control; sometimes by inducing excessive secretion of growth factors that stimulate mitosis, or the production of excessive growth factor receptors |
What must happen to an oncogene to promote cancer? | 1) Gain of function
2) Dominant
3) One copy of the gene needs to be activated |
What do tumour-suppressor genes do? | Inhibit by opposing oncogene action, coding for DNA-repair enzymes |
What type of mutation must happen to tumour-suppressor genes to cause cancer? | 1) Loss of function
2) Recessive - both copies of the gene need to be inactivated |
What are the 6 successful qualities of a cancer cell? | 1)Independent of external growth signals
2)Insensitive to external anti-growth signals
3) Able to avoid apoptosis
4) Capable of indefinite replication
5) Capable of sustained angiogenesis
6) Capable of tissue invasion and metastasis |
What are the different types of cancer? | Familial (genetic-1%) and Sporadic (non-genetic-99%) |
What are familial cancers mostly caused by? | Autosomal dominant traits and due to inherited mutations of tumour suppressor genes |
What can cause sporadic cancers? | Exposure to carcinogenic agents and unrepaired DNA replication errors |
What do sporadic cancers result in? | Somatic activation/inactivation of cancer genes |
What growth factors do oncogenes secrete? | EGF and PDGF |
Which cyclins/cyclin-dependent kinases do oncogenes use? | Cyclin D1, CDK4 |
What are the main groups of tumour suppressor genes? | -Antiproliferative (eg CDKN2A, RB)
-Pro-apoptotic (eg TP53)
-DNA repair and genome stability (eg MSH2, MSH6, TP53 and BRCA1) |
What is carcinogenesis driven by? | Clonal selection and genomic instability |
What is the tumour of origin called? | The primary tumour or primary neoplasm |
What is the process called when cancer spreads to surrounding cells? | Invasion |
What is the process called when malignant cells travel to distant tissues and organs and establish secondary tumours? | Metastasis |
Which base sequences do telomeres consist of? | Repeats of TTAGGG |
Which enzyme creates the telomeres? | Telomerase |
When is telomerase active? | Active in early life, but inactive in adulthood |
What happens when telomerase is abnormally mutated? | The abnormal cells continue to divide indefinitely |
What can malignant tumours do that benign tumours cannot? | Spread by invasion and metastasis |
What 5 main categories does the summary staging system class cancers as? | 1) In Situ
2) Localised
3) Regional
4) Distant
5) Unknown |
Which staging system is commonly used to classify cancers? | TNM staging |
What does each letter of the TNM system stand for? | T: size and/or extent of primary tumour
N: whether cancer cells have spread to nearby regional lymph nodes
M: whether metastasis or the spread of the cancer to other parts if the body has occurred |
What would breast cancer described as T3 N2 M0 mean? | A large tumour that has spread outside the breast to nearby lymph nodes but not to the other parts of the body |
What are the T stages of primary tumour? | TX: Primary tumour cannot be established
T0: No evidence of primary tumour
Tis: Carcinoma In Situ
T1,T2,T3,T4: Size and/or extent of cancer |
What are the N stages of regional lymph nodes? | NX: regional lymph nodes cannot be evaluated
N0: No regional lymph node involvement
N1,N2,N3: degree of regional lymph node involvement (number and location of lymph nodes) |
What are the M stages od distant metastasis? | MX: Distant metastasis cannot be evaluated
M0: No distant metastasis
M1: Distant metastasis is present |
What is an invasive ductal carcinoma? | Invasive: Cancer has invaded or spread to the surrounding tissues of the breast
Ductal: the cancer began in the milk duct
Carcinoma: any cancer that begins in the skin or other tissues than internal organs |
What percentage of all breast cancers are invasive ductal carcinomas responsible for? | 80% |
What might treatments for invasive ductal carcinoma involve? | Surgery, radiotherapy, chemotherapy, hormone therapy, biological therapy |
What are the 2 types of needle biopsies that might be done to a cancer? | Fine needle biopsy and core biopsy |
What name is given to the process od diagnosing diseases by looking at single cells, or a small cluster of cells? | Cytology or Cytopathy |
What are cancer biopsies looked at for? | -Size and shape of the cells
-Size and shape of the cell's nucleus
-Arrangement of the cells |
What other test might pathologists use to determine if a cancer is ductal or lobular? | E-cadherin |
What are microcalfications? | Calcium deposits found in both cancerous and non-cancerous breast tissue |
What might microcalcifications indicate? | Certain patterns of calcification (eg tight clusters with irregular shapes) may indicate breast cancer |
What are some common causes of benign breast calcifications? | 1)Calcium within the fluid of a benign cyst
2)Calcifications associated with a dilated milk duct
3)An old injury to the breast
4)Inflammation due to infection
5)Skin calcifications caused by dermatitis or metallic residues from powder
6)Radiation |
What happens to the cortex of an abnormal lymph node? | Tends to become markedly hypoechoic (gives off few echoes in ultrasonography) |
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