Block C Lecture 1 - Basics of Cancer and Therapeutic Targets Flashcards
What is cancer?
A term which describes a group of diseases which are characterised by the uncontrolled growth and division of abnormal cells within the body. These cells can invade surrounding tissues and spread to distant parts of the body, disrupting bodily functions
(Slide 3)
What is the difference between benign and malignant tumours?
Benign tumours grow locally and don’t invade adjacent tissues whereas malignant tumours invade nearby tissues and metastasise
(Slide 4)
What does the term “metastasise” refer to?
When cancer cells spread from the original (primary) tumour site to other parts of the body, forming secondary tumours.
(Slide 4)
What 2 continents have the highest proportion of cancer deaths compared to their incidence?
Asia and Africa
(Slide 5)
What 2 ways are cancerous diseases described / characterised by?
The organ in which they originate from
The cell type in which they originate from
(Slide 6)
How does cancer arise?
From the accumulation of mutation in genes which control growth and proliferation of cells (such as oncogenens and tumour suppressor genes) - leading to altered gene expression
(Slide 8)
What are 3 examples of genes which can cause cancer if they experience mutations?
Tumour suppressor TP53 gene
RB1 gene
BRCA1/2 genes
APC gene
PTEN gene
CDKN2A gene
SMAD4 gene
Oncogenes
KRAs genes
BRAF gene
HER2 (ERBB2) gene
EGFR gene
MYC gene
ABL1 gene
PIK3CA gene
ALK gene
Note: We probably don’t have to know these specifically (other than maybe tumour suppressor TP53 and oncogenes in general), but it will definitely be useful for extra marks in essay questions
(Slide 9)
How can mutations in oncogenes or tumour suppressors lead to different protein expression in cancer cells?
Oncogenes - mutations can result in a mutant protein or the overproduction of the wildtype protein in cancer cell compared to normal cell
Tumour suppressors - the protein is silenced in cancer cell
(Slide 10)
What are 2 examples of conditions which can increase the risk for cancer 5-10%? (bonus points for saying which cancer).
Answers Include:
Xeroderma Pigmentosum - Skin cancer
Wilm’s tumour - Kidney cancer
Familial adenomatous polyposis - colon and rectum cancer
BRCA 1/2 Mutation - breast and ovarian cancer
(Slide 11)
What is a somatic mutation?
A mutation which occurs after conception, however they can (but don’t always) occur before birth
(Slide 12)
What are 3 examples of types of somatic mutations which can lead to cancer?
Single base change mutations (point mutations)
Additions
Deletions
(Slide 12)
Why does the chance of cancer occurring increase over time?
As cancer is a multi-stage process which is caused by the accumulation of multiple mutations, not just a single one.
The more time that passes, the higher the chance of these mutations randomly occurring, if just a single mutation caused cancer then the appearance of it would be more sporadic, sudden and seemingly random
(Slide 13)
What chromosome is found in most chronic myeloid leukaemia (CML) patients, and how is this formed?
The Philadelphia (Ph) chromosome, which is made due to a translocation between chromosomes 9 and 22
(Slide 14)
Does the site of chromosomal breaking and re-joining in CML patients change between different cells in the patients and / or different patients?
The site is identical in all cells in a particular patient, however it differs between patients
(Slide 14)
What is the definition of the “hallmarks of cancer”?
Biological capabilities which are acquired as a result of mutations which occur during the development of cancer, which enable tumour growth, survival and metastasis
(Slide 16)
What are 7 examples of the hallmarks of cancer?
Answers Include:
Tumour-promoting inflammation
Limitless replicative potential (known as immortality)
Evasion of apoptosis
Genomic instability
Tissue invasion and metastasis
Sustained angiogenesis (process of forming new blood vessels)
Self-sufficiency in growth signals
Reprogramming of energy metabolism
Insensitivity to anti-growth signals
Evasion of the immune system
(Slide 16)
How can cancers become more heterogenous as they progress?
As at each stage of progression, some individual cells can acquire an additional mutation or epigenetic change which gives it a selective advantage over neighbouring cells, which makes it better able to thrive in its environment
(Slide 17)
What does the term “tumour grade” describe?
The aggressiveness of the tumour, likelihood of metastasis, the response to the treatment and prognosis
(Slide 19)
What does the term “tumour stage” describe?
The extent of the disease, likelihood of metastasis and the treatment decision
(Slide 19)
What do DNA / molecular profiles allow?
For treatment to be tailored to specific patients
(Slide 19)
What are the 4 types of breast cancer?
Ductal carcinoma in situ (DCIS) (non-invasive)
Invasive ductal carcinoma (IDC)
Lobular carcinoma in situ (LCIS) (non-invasive)
Invasive lobular carcinoma (ILC)
(Slide 20)
What does in situ mean?
In the natural / original position or place
(Slide 22)
What are the grades in the Bloom Richardson grading system for breast cancer and what are the requirements for these?
Criteria focusses on the degree in which the tumour retains normal glandular structure
Grade 1 - 75% of tubules (well differentiated)
Grade 2 - 10-75% of tubules (moderately differentiated)
Grade 3 - <10% of tubules (poorly differentiated)
(Slide 21)
What does TNM stand for in reference to the TNM staging system in breast cancer?
T - tumour size and extent of spread in the breast
N - lymph node involvement
M - metastasis (spread to distant organs)
(Slide 22)
