Lecture 4 - Cancer Flashcards
Most common types of cancer in males (Aus)?
- prostate
- colorectal
- melanoma
- lung
Most common types of cancer in females (Aus)?
- breast
- colorectal
- melanoma
- lung
~how many cases of cancer annually, worldwide?
> 14 million
~how many people die of cancer annually, worldwide?
8.2 million
~how many people living with cancer in the world today?
21 million
describe the difference between cancer and neoplasia?
neoplasia = ‘new growth’, these new growths may be benign or malignant. Cancer implies malignancy, so cancer is a type of neoplasm
define neoplasia?
- disorder of cell growth leading to excessive proliferation of a single cell and its clonal progeny
- occurs independently of physiologic growth-regulatory stimuli
- may be benign or malignant
- due to a series of acquired mutations
explain the 3 key characteristics of a neoplastic growth?
- Unregulated by normal physiologic mechanisms
- Irreversible
- Monoclonal (arises from singular abnormal cell)
A neoplasm is colloquially known as?
A tumor
State the principle fighter of a bacterial infection in the human body?
Neutrophils
What is the fundamental difference between a cancer cell, and a normal cell?
Normal cells send, receive and interpret signals which solve as SOCIAL CONTROLS: cells behave responsibly with resting, dividing, dying etc.
Cancer cells do not abide by social controls, they divide without normal constraints and invade territories belonging to other cells
why do cancer cells divide so uncontrollably?
due to a mutation in the neoplastic cells giving them a survival and growth advantage
t/f: cancerous growths are always homogenous (all same type of cancer)
false - often heterogenous, this is why chemotherapy isn’t always effective and immunotherapy is a better approach
t/f: cancer can be caused by a singular mutation
false - needs to be a series of mutations, not just one
define hyperplasia?
increased proliferation of cells which is ‘occurring normally’ (observing social controls)
compare or contrast hyperplasia and neoplasia?
Main difference = neoplasia involves mutated cell, hyperplasia involves non-mutated cell
- in hyperplasia growth occurrs normally (social controls) whereas in neoplasia it is abnormal
- hyperplasia is reversible whereas neoplasia is not
- neoplasia originates from a single cell, whereas hyperplasia may originate from one or many cells
describe whats meant by the ‘degree of differentiation’ of tumor cells?
the extent to which the tumor cells resemble the normal tissue of origin, structurally and functionally
well differentiated= close resemblance to tissue of origin, likely benign
poorly differentiated= minimal resemblance to tissue of origin, likely malignant
(note: normal healthy tissue contains a variety of healthy cells, so the normal cells are well differentiated into their roles, whereas cancerous cells aren’t differentiated into their roles)
explain what’s meant by an ‘anaplastic’ tumor?
The worst!
One which is poorly differentiated - so it doesn’t resemble the tissue of origin to the point where it cannot be determined what the tissue of origin is, and is likely malignant
if a tumour is well differentiated, what does this mean in terms of its appearance and apparent threat level?
it appears normal - same as original tissue, likely benign
if a tumor is poorly differentiated, what does this mean in terms of its structure and apparent threat level?
it appears different to original tissue from which it came, the cells are poorly differentiated meaning they haven’t taken up their normal roles - this is likely a malignant tumor
All neoplasms have 2 components - what are they?
- Parenchyma - proliferating cells of the tumor, defines the behavior
- Supportive stroma - CT, BV, framework from which parenchyma grows
(note: this doesn’t only apply to tumors - parenchyma always means function portion of tissue etc)
Contrast features of benign and malignant neoplasms?
- benign margins are well defined, malignant are poorly defined and locally invasive
- benign growths don’t invade surrounding tissue whereas malignant does, destroying it and spreading (metastasizing)
- benign prognosis good (death unlikely), malignant is poor
t/f: benign tumors do not have major abnormalities in the regulation of growth
true
t/f: benign tumors grow locally and rapidly
false - locally and slowly