Week 1 - Cancer Flashcards
(125 cards)
1
Q
Define cellular regulation
A
- all functions carried out within a cell to maintain homeostasis
- includes responses to extra cellular signals
2
Q
What are two key concepts of cellular regulation?
A
- Proliferation
2. Differentiation
3
Q
Describe proliferation and differentiation in relation to cancer cells
A
- cancer cells fail to differentiate and excel at proliferation
4
Q
Cancer is a group of _______
A
More than 200 diseases
5
Q
What is cancer characterized by?
A
- uncontrolled and unregulated growth of cells (proliferation)
6
Q
Who does cancer occur in?
A
- in people of all ages & ethnicities
7
Q
Approximately how many people in Canada have a chance of developing cancer?
A
- 44% (1 in 2.3)
8
Q
Describe the chances of developing cancer for each sex: is it similar chances?
A
- men 45%
- women 43%
= very similar
9
Q
What are the top 3 cancers to occur in men?
A
- Prostate
- Lung & bronchus
- Colorectal
10
Q
What are the 3 most common cancers to occur in women?
A
- Breast
- Lung and bronchus
- Colorectal
11
Q
Which age group has the highest percentage of cancer cases?
A
50-69 (44.9%)
12
Q
What is the leading cause of death in ever Canadian province?
What is the second?
A
- since 2008, cancer has been the leading cause (30% of deaths)
- heart disease is in second (21% of deaths)
13
Q
What are risk factors for developing cancer? (4)
A
- excessive body weight
- lack of physical activity
- unhealthy eating habits
- excessive exposure to the sun
14
Q
What are some lifestyle habits that reduce the risk of developing cancer? (3)
A
- avoid or reduce exposure to known or suspected carcinogens
- eat a balanced diet (includes variety)
- exercise regularly
15
Q
What are carcinogens?
A
- any substance that is known to cause or promote the formation of cancer
16
Q
What are some examples of carcinogens?
A
- cigarette smoke
- excessive sun exposure
17
Q
What is a neoplasm
A
- a tumour
- an abnormal mass of cells which grow and divide without response to normal regulatory controls
18
Q
What is a benign tumour?
A
- noncancerous tumour
- does not spread to other tissues or metastasize
19
Q
What is a malignant tumour?
A
- cancer
20
Q
What is the cause of cancer?
A
- cause is considered unknown
- but current theory of cancer formation involves multiple sequential mutations that impairs a cell’s ability to control it’s cell cycle and replication
21
Q
What are the 4 characteristics of malignant cells?
A
- Proliferation without limits ( will endlessly divide)
- Evasion of apoptosis
- Acquisition of vasculature
- Invasion of other tissue and metastasis
22
Q
Why do malignant cells acquire vasculature?
A
- as the cells & tumour grows, it needs lots of O2 and nutrients and will become ischemic
- they acquire vasculature to overcome this
23
Q
List the phases of the normal cell cycle
A
- G1
- S stage
- G2 stage
- Mitosis
- G0
24
Q
What occurs during G1
A
- growth phase
- relatively dormant, some RNA and protein synythesized
25
What occurs during S phase
- DNA synthesis
26
What occurs during G2
- more growth
- prep for mitosis
- some RNA synthesized
27
What occurs during mitosis
- cellular division
| - the parent cell splits into 2 daughter cells
28
What occurs during the G0 phase?
- resting phase
| - cells are not in the process of cellular division
29
What two types of genes are affected by mutations that contribute to the development of cancer?
1. Proto-oncogenes
| 2. Tumour suppressor genes
30
What do proto-oncogenes do
- regulate normal cellular processes
| - ex. Promote growth
31
What are proto-oncogenes called if they are mutated?
- they become oncogenes
32
What do tumour suppressor genes do?
- suppress growth
33
What may happen if tumour suppressor genes are mutated?
- cell may not be able to stop growing
34
What are two examples of tumour suppressor genes?
1. BRCA1 (mutation in this gene can cause breast cancer)
| 2. P53 (most commonly mutated gene)
35
Research suggests that human neoplasms result from a. Combo of mutations that activate ______ and inactivate ________
- activate oncogenes
| - inactivate tumour suppressor genes
36
What is an oncogene
- gene that has potential to cause cancer
| - was once a proto-oncogene
37
What is carcinogenesis
- process by which normal cells become transformed into malignant cells
38
What does carcinogensis typically involve?
- changes in DNA
| - most require multiple changes in DNA , which is caused by multiple factors
39
List 5 things that may cause mutations in the DNA
1. Genetic (ex. BRCA1 mutation)
2. Chemical
3. Environment (ex. UV rays)
4. Viral or immunological
5. Or from causes not yet identified
40
What are the 3 steps in cancer development
1. Initiation
2. Promotion
3. Progression
41
What occurs during initiation stage of cancer?
- the normal cell gets altered by genetic mutation
- genetic mutation can occur thru inherited mutation, after exposure to a carcinogen, an error during DNA replication, etc.
42
What occurs during the promotion stage of cancer?
- the presence of promoting factors increase cancer development
43
What can impact promotion of cancer?
- lifestyle factors
| - exposure to steroid hormones such as estrogen and testosterone
44
Describe how estrogen and testosterone can cause promotion during puberty
- during puberty, these hormones are produced to tell cells in reproductive organs to enter the cell cycle & proliferate
- but at the same time, it will also promote the cancer cells to continue dividing
45
Describe the progression stage of cancer
- this when you have evidence of clinical disease
| - the cancer then spreads & metastasizes
46
What cancer is associated with Epstein Barr virus
- burkitts lymphoma
47
What cancer is associated with human immunideficiency virus ( HIV)
- kaposi sarcoma
48
What cancer is associated with hep B virus
- hepatic Elul are carcinoma
49
What cancer is associated with human papillomavirus
- squamous cell carcinoma (especially cancer of the cervix)
50
What are the 6 local effects of tumours?
1. Compress blood vessels & outgrow their blood supply
2. Nutrient trapping
3. Replace normal tissue = loss of function
4. Liberate toxins & enzymes = destroy normal & tumour tissue
5. Obstruct passageways
6. Pain
51
How do tumours cause pain
- by putting pressure on sensory nerves or a visceral structure
- inflammation and bleeding also contribute to pain
52
Is pain an early sign of cancer?
- it’s rarely an early sign
53
What does tumours compressing blood vessels and outgrowing their blood supply cause?
- causes ischemia, inflammation, and tissue necrosis
54
List two examples of how tumours can block a passageway?
- in the lungs can block air flow
| - can obstruct the colon
55
List the 6 systemic effects of cancer
1. Weight loss, tissue wasting
2. Fatigue
3. Bleeding
4. Anemia
5. Infections
6. Paraneoplastic syndromes
56
What causes weight loss, tissue wasting, and fatigue? (4)
- anorexia
- increased catabolism ( breakdown)
- nutrient trapping
- inflammation
57
What is cachexia?
- tissue/muscle wasting —> weight loss
58
How does the inflammatory response contribute to cachexia
- the release of cytokines contributed to increased catabolism & muscle wasting
- cytokines also cause decreased appetite, nausea, etc.
59
What causes bleeding due to tumours? (3)
- tumour necrosis and erosion of blood vessels
| - bone marrow suppression
60
Bone marrow suppression can occur as a systemic effect due to what 3 things?
1. A specific tumour
2. Invasion of the marrow
3. Secondary to therapy
61
What bleeds are specifically difficult to treat?
- GI bleeds
62
What causes anemia due to a tumour? (3)
- can result from blood loss
- iron deficiency (due to nutrient trapping)
- or bone marrow suppression/invasion
63
Why do infections occur as a systemic effect of cancer?
- bone marrow suppression/invasion =decreased WBC = immunocompromised
64
What other factors can predispose cancer patients to infections?
- immobility, muscle wasting, fatigue can cause pooling of respiratory secretions and stasis or urine = predispose to opportunist infections
65
What are paraneoplastic syndromes?
- symptoms that occur that are not attributed to the direct effects of a tumour or metastasis
- any unusual symptoms
66
What are examples of paraneoplastic syndromes
- abnormal hormones or cytokines secretion by a tumour
- bone marrow suppression
- dementia
- abnormal clotting
- fever
- cachexia
67
Malignant tumours spread by producing ______
- secondary tumours that are identical to the original primary tumour
68
What 3 ways do tumours spread?
1. Invasion of neighbouring tissues
2. Metastasis
3. Seeding
69
Describe invasion of a tumour
- when tumour cells grow into adjacent tissue
70
How does invasion occur?
- tumour cells lack adhesion molecules & secrete enzymes that allow them to break down the confining connective tissue
71
What is metastasis
- when tumour cells break free of a tissue and are circulated to distant tissues in the blood or lymph
72
Where do secondary tumour attach during metastasis
- either contained by local lymph nodes
| - attach to capillary beds they come across
73
What is the most common site of metastasis ? Why?
- the lungs
| - pulmonary capillaries are often the first beds encountered by systemic tumour cells
74
What are all 5 main sites of metastasis? What is the second most common location after the lungs?
1. Brain & cerebrospinal fluid
2. Lungs
3. Liver (second most common)
4. Adrenals
5. Bone
75
What is seeding
- involves the spreading of tumour cells along membranes or within fluids other than blood or lymph
76
What type of cancer commonly spreads thru seeding? Why?
- ovarian
| - it is surround by a continuous peritoneal membrane
77
What are the 3 ways tumour can be classified by?
1. Anatomical site / tissue of origin
2. Historical analysis (grading of severity)
3. Extent of disease (staging)
78
what are 4 examples of cancer classified based off tissue of origin
1. Carcinomas
2. Sarcomas
3. Lymphomas and leukemias
79
Where do carcinomas originate from?
- from epithelial tissues
| - includes the ectoderm and endoderm
80
What is included in the embryonal ectoderm
- skin
- glands
- epithelium
81
What is included in the endoderm
- mucus membrane of respiratory tract, GI, and GU tracts
82
Where do sarcomas originate from
- the embryonal mesoderm
83
What is included in the mesoderm
- CT, muscle, bone, and fat
84
Where do lymphomas and leukemias originate from
- the hematopoietic system
85
What is the hematopoietic system?
- system responsible for producing the element of blood (RBC, WBC, platelets)
86
What is the difference between lymphomas and leukemias
- lymphoma = originates in the lymph nodes
| - leukemias = occurs in the bone marrow
87
What is the difference between cancer grading and staging?
- grading = based on how the cancer cells look, determines how fast it will grow
- stage = says the how much cancer is in ur body, where it is, and how far it has spread
88
How many grades are there for abnormal cells?
4
89
Describe grade 1 cancer cell
- cells differ slightly from normal cells
| - cells are well differentiated
90
Describe grade 2 of cancer cells
- cells are more abnormal
| - moderately differentiated
91
Describe grade 3 of cancer cells
- cells are very abnormal
| - poorly differentiated
92
Describe grade 4 of cancer cells
- cells are immature & primitive
- undifferentiated
- cell of origin is difficulty to determine
93
What is staging useful in?
- determining the prognosis (course of development) of a cancer & the most appropriate therapy
- determines the extent of the disease process within the body
94
How many different stages of cancer are there?
5 ( ranges from 0-4)
95
Describe stage 0 of cancer
- cancer in situ
- cancer can be removed & cured
- new, early cancer
96
What does situ mean
- in its original place
| - has not spread
97
Describe stage 1 of cancer
- tumour limited to tissue of origin
- localized tumour growth
- removal = cured
98
Describe stage 2 of cancer
- limited local spread to lymph nodes but not beyond these local nodes
- removal of tumour and lymph nodes = cured
99
Describe stage 3 of cancer
- extensive local & regional spread to lymph nodes
100
Describe stage 4 of cancer
- metastasis
- 2ndary tumour present
- rarely cured and typically lethal
101
Which stages of cancer are considered or potentially curable? Which aren’t?
- stages 0-2 = curable
| - stages 3&4 = not
102
What classification system is often used to stage a cancer?
TNM classification system
103
What does the T stand for in TNM classification
- tumour size & invasiveness
| - involves measuring the diameter and different sizes correlate to a stage depending of the type of cancer
104
What does the N stand for in TNM classification
- spread to lymph Nodes
105
What does M stand for in TNM classification
- metastasis
| - if does = stage 4
106
Are the specifics of the TNM classification system the same for every cancer?
- no it changes for each cancer
107
What is lymphoma
- malignant tumours of the lymphocytes
108
Does lymphoma typically involve B or T lymphocytes?
- 90% involve B lymphocytes
109
What are risk factors for lymphoma (7)
- previous exposure to radiation
- chronic immunosuppressive
- autoimmune disease
- HIV
- hep B/C
- helicobacter pylori infection
- exposure to herbicides & pesticides have also been suspected
110
What is the most common clinical manifestation of lymphoma
- lymphadenopathy
111
Describe the development of lymphoma
- typically begins in a single lymph node but will metastasize to adjacent nodes & other areas of the body
112
What nodes are most commonly affected by lymphoma (3)
- cervical
- supraclavicular
- axillary
113
What are key characteristics of lymphoma (4)
- asymmetric enlargement of lymph nodes
- weight loss
- fatigue
- immunosuppression
114
What are the 2 main categories of lymphomas
1. Hodgkin disease
| 2. Non-hodgkin’s disease
115
Describe cellular origin in hodgkins vs non-hodgkins
- hodgkins = b lymphocytes --> reed sternburg cells
| - non-hodgkins = b lymphocytes (90%) and t lymphocytes (10%)
116
Describe the extent of disease in hodgkins vs no hodgkins
- hodgkins = localized to regional, but may be bulky
| - non = disseminated (spread)
117
What are B symptoms? (3)
- fever
- night sweats
- Weight loss
118
Describe the presence of B symptoms in hodgkins vs no hodgkins
- hodgkins = common
| - non = less common
119
Describe extranodal involvement in hodgkins vs nonhodgkins
- extranodal involvement = spread to an atomic sites other then the lymph nodes
- hodgkins = rare
- non = common
120
Describe stage 1 of hodgkins
- involvement of a single lymph node or a single extranodal site
121
Describe stage 2 of hodgkins
- involvement of 2 or more lymph node regions on the same side
122
Describe stage 3 of hodgkins
- involvement of lymph nodes on both sides of the diaphragm
123
Describe stage 4 of hodgkins
- disseminated disease of one or more extralymphatic organs or tissues with or without associated lymph node involvement
124
What is the Canadian Cancer Society’s 7 Steps to Heakth?
1. Be a non-smoking and avoid second hand smoke
2. Eat well
3. Be active
4. Use sun sense
5. Follow cancer screening guidelines
6. Visit ur doctor or dentist if u notice anything abnormal
7. Follow safety instructions at home and work for storing and disposing of hazardous materials
125
What is meant by “eat well”
- 5-10 servings of fruits and veggies
- high fibre
- low fat
- low alcohol
