Exam 1: Neoplasia Flashcards
Define neoplasia
• New growth; abnormality of cellular growth
What cancer has the highest incidence in men and women
prostate and breast
What cancer has the highest mortality in men and women?
lung and bronchus
What is the normal cell cycle?
Go phase- cell may leave cycle and remain inactive or reenter at another time
G1 phase-gap 1, preparing for DNA replication and mitosis through protein synthesis and increase in organelle and cytoskeletal elements
S phase-DNA synthesis
G2 phase-gap 2, premitotic phase, enzymes and proteins synthesized and moved to proper sites
M phase-mitosis, cell division, formation of two daughter cells
What are the differentiating characteristics of normal cells vs malignant cells?
normal-o Slow/ no cell division (spend time in G0)
o Specific morphology (specific shape for organ or tissue)
o Small nuclear to cytoplasmic ratio
o Performs specific differentiated function
o Tightly adherent
o Nonmigratory
o Contact inhibition
malignant-
Rapid and continuous cell division (little time in G0)
o Anaplastic morphology (cells don’t look the same)
o Large nuclear to cytoplasmic ratio
o Lose some or all differentiated functions
o Loosely adherent
o Able to migrate
o Loss of contact inhibition (invasion)
o Poorly regulated growth (immortality)
What are benign tumors
• Normal cells growing in the wrong place at the wrong time at the wrong rate
What are the stages of carcinogenesis
• Initiation, promotion, and progression
Define and know the role of the following in carcinogenesis:
Proto-oncogenes
- Code for components of the cellular growth-activation pathways
- When erroneously activated, becomes an oncogene and promotes cancer
Define and know the role of the following in carcinogenesis: genetics
- Familial polyposis – increased risk of colon cancer
* Breast, ovarian, and colon – increased risk of breast cancer with BRCA1 mutation
define and know the role of the following in the carcinogenesis: tumor suppressor genes
• Rb gene
o Codes for a large protein of the cell nucleus
o Master brake of the cell cycle
o Defective pRB is common in several cancers
• P53 gene
o Inhibits cell cycling; accumulates after DNA damage and stalls cell division to allow for cell repair, may signal apoptosis
o More than half of all tumors lack functional P53
• BRCA1 and BRCA2
o Women with defect have 85% risk of breast cancer
Define and know the steps of carcinogenesis
Initiation (hyperactivity vs inactivity)
- Carcinogens mutate cell’s genes: initiators
- Irreversible event
- Must occur in a cell able to divide
- Can develop from just one cell
- Two mutational routes: hyperactivity (over expression of oncogene) inactivity (tumor suppressor gene) (need both for initiation)
- Carcinogenesis – inactivation of tumor suppressor gene and activation of oncogene
Define and know the steps of carcinogenesis: promotion
- Enhance growth of initiated cells
- Permit expression of altered gene
- Requires chronic exposure
- Promoters: hormones, drugs, chemicals
Define and know the steps of carcinogenesis: Progression (what is angiogenesis)
- Detectable tumor size (1 cm, 1 billion cells, divided 30 times)
- Needs own blood supply
- Angiogenesis – forming new blood vessels
Primary site vs metastatic site
- Primary – original tumor from transformed cells
* Metastatic (secondary) – tumor established in another organ or tissue
List some common carcinogens and define complete vs incomplete, intrinsic vs extrinsic
• Extrinsic – environmental
• Intrinsic – inside the body
o Immunocompetence
o Age
o Genetics
• Complete carcinogen – both initiate and promote
• Incomplete carcinogen – pure initiating agent, others only promoting agents, may require repeated exposure
• Chemical carcinogens – soot, tar, oil, tobacco smoke, vinyl chloride, smoked food
• Physical carcinogens – radiation (ionizing and ultraviolet), chronic irritation (smoke)
• Viral – Hep B and C, herpes simplex type 2, Epstein barr, human t-cell leukemia virus type 1, HPV
• Dietary – low fiber, high fat, preservatives, dyes
• Pharmaceutical – diethylstilbestrol (given after birth) – increased risk of cervical cancers of children of exposed mothers, estrogen (endometrial and breast cancer), alkylating agents (leukemia and lymphomas), immunosuppressive agents
Which is the most significant of the carcinogens?
• Polycyclic hydrocarbons (tobacco smoke)
Define metastasis, what is the mechanism
• Metastasis – establishment of cancer tumor colonies distant from the originating site
• Tumors secrete chemotaxic substances, tumor cells break free and are transported
• Routes:
o Local seeding – cancer cells are shed in the area of the primary tumor
o Blood-borne (most common)
o Lymphatic spread – related to number, structure, and location of lymph nodes and vessels
• Frequently go to the first capillary bed encountered
• Liver is common site
• Organ tropism – certain cancers have an affinity for metastasis to certain other organs
Why do we grade and stage tumors?
• Determine the course of the disease and aid in selecting an appropriate treatment
determine cell characteristics, examine cells and determine level of differentiation and number of mitoses, grades I, II, III, IV with increasing anaplasia or lack of differentiation
grading
determine clinical spread, surgery to determine tumor size or lymph node involvement, determine course of treatment
staging
What is differentiation and why is that important in the process
• Cell becoming more specialized, important because cells lose differentiation as cancer progresses, initially may be able to tell if tumor is primary site based on similar cells to surrounding tissue, later on may not be able to determine as cells lose differentiation
What is the TNM system? Be able to identify which classification would have better/worse prognosis?
- T = primary tumor
- N = regional lymph nodes
- M = distant metastasis
What are tumor markers, list some common, how are they used?
- Tumor markers – substances produced by the tumor or released by normal cells in response to the presence of a tumor
- Some are normal but become overexposed with cancer
- Some are produced in fetal development but reappear in later life as result of cancers
- Ex: Prostate specific antigen (PSA), alpha fetoprotein (AFP), carcinoembryonic antigen (CEA)
- Used for screening, establishing prognosis, monitoring treatment, and detecting recurrent disease
List the seven warning signs of cancer
• CAUTION o C – changed in bowel or bladder habits o A – a sore throat that does not heal o U – unusual bleeding or discharge o T – thickening or lump in breast or elsewhere o I – indigestion or difficulty swallowing o O – obvious change in a wart or mole o N – nagging cough or hoarseness
List some effects of cancer on individuals; complications?
• Effects o Pain (earliest sign) o Cachexia (weight loss) o Anorexia o Nausea/vomiting (persistent) o Increased metabolism (increased HR, BP) o Pancytopenia (decrease in all levels on CBC) o Alopecia o Oral ulcers
• Complications o Changes in organ function Malignant may cause organ failure Benign may cause over-secretion o Physical effects Compression of nerves, veins, intestinal obstruction o Ectopic hormone secretion Paraneoplastic disorders o Tissue breakdown Protein wasting, bone breakdown
