Week 3 - Oncology Flashcards
What is prevalence?
Number of persons with cancer at a given point in time divided by total population living at that time = prevalence
What is incidence?
It is defined as number of persons developing cancer in a specified period of time divided by total population living at that time = incidence
What is mortality?
It is defined as number of persons dying of cancer in a specified period of time divided by total population living at that time = mortality
What is cancer?
The term ‘Cancer’ refers to malignant neoplasms. Cancer is a term used for diseases in which abnormal cells divide without control and are able to invade other tissues. Cancer cells are derived from normal cells that have undergone neoplastic transformation, that is, an irreversible process leading to the transformation of a healthy cell into a cancer cell. These cancerous cells can invade and destroy surrounding tissue and spread to distant parts of the body.
What does the cell cycle consist of?
> Gap 1 - Post Mitotic/Pre synthesis phase
Synthesis
Gap 2 - Post Synthetic/pre-mitotic phase
Mitosis
Go (resting) phase
Cell Cycle: Gap 1 - Post Mitotic/ Pre Synthesis Phase
- Lasts from 18-30 hours
- Time from the end of mitosis to DNA synthesis
- Primarily a stage of ‘readiness’, in which cells start to make enzymes for DNA synthesis and prepare for entry into the synthesis phase
Cell Cycle: Synthesis
- Lasts 7-20 hours
- Proteins containing DNA are copied
- Synthesis of DNA leads to doubling of the total amount (DNA is replicated)
- Normal cell reproduction is dependant upon orderly synthesis of genetic material
- Cells are most vulnerable to damage during the synthesis phase
Cell Cycle: Gap 2 - Post Synthetic/Pre-Mitotic Phase
- 2nd gap period
- Lasts from 2-10 hours
- Errors in replication are corrected
- Specialised proteins and RNA are synthesised
- Cells are basically awaiting entry into the mitotic phase
Cell Cycle: Mitosis
- Lasts 30 mins to 2 hours
- Cell division occurs
- Duplication of the DNA MUST be complete before cells enter the mitotic phase
- 4 sub phases: (Prophase, Metaphase, Anaphase, Telophase)
Cell Cycle: Go (resting) phase
- There is an additional phase in the cell cycle
- Some cells do not enter the gap 1 pool, but enter the Go state, where they become temporarily quiescent
- In the Go, cells are not active in the cell cycle
- Lasts from a few hours to a few years
- Since at any given time, only 15-30% of cells are cycling, the Go cells are the largest population
What is a tumour growth fraction?
The growth fraction is the ratio of the total number of cells to the number of dividing cells.
What does it mean when cancer cells have the capacity to ‘intravasate’ and ‘extravasate’?
This means that cancer cells have the ability to enter and leave the circulatory and lymphatic systems.
What are the 8 stages of the metastatic cascade?
- Tumour initiation
- Progression
- Proliferation
- Angiogenesis
- Invasion/ Intravasation
- Extravasation
- Colony formation
- Evasion of host defences
Emotional responses following cancer diagnosis include:
- Shock
- Disbelief
- Anger
- Confusion
- Depression
- Despair
- Grief
- Anxiety
Physical / behavioural responses following cancer diagnosis include:
- Sleep disturbance
- Appetite changes
- Altered sexual interest
- Headaches
- Heart Palpitations
- Feeling ‘stressed’ and ‘on edge’
- Wanting to be around others/ social withdrawal
- Substance use / abuse
What is metastatic cascade?
The metastatic cascade describes the process whereby aggressive cancer cells leave the primary tumor, travel through the bloodstream, and eventually reach distant organs to develop one or several metastases.
What is clinical distress related to?
- Disease status
- Treatment tolerance
- Symptom intensity
- Symptom intensity and frequency
- Lifestyle effects of symptom intensity and frequency
- Quality of life
Examples of psycho social problems:
- Adjustment disorders to illness and/or changes in care
- Feelings of isolation from family
- Family conflict
- Decreased quality of life
- Decisions surrounding advanced directives
- Abuse/neglect
Treatments for mild psycho-social problems include the following :
- Education materials
- Support and education groups
- Resource lists (interdisciplinary referrals)
- Community resources
- Relationship counselling
- Grief counselling
Treatments for more severe psycho-social problems may include:
- Patient counselling / psychotherapy / +/- Medication
- Family counselling / psychotherapy
- Sexual counselling
- Grief counselling
- Assistance in strengthening coping styles: Relaxation techniques, meditation techniques
- Community resources
- Assistance with problem resolution
- Patient advocacy
- Education regarding coping skills
Pastoral and spiritual support for psychosocial problems may include the following discussions:
- Questioning one’s belief system
- Loss of faith
- Questions regarding life’s purpose
- Isolation from religious community
- Issues with treatment suggestions and religious beliefs
- Ritual requests
Examples of practical problems:
- Transportation issues and parking costs
- Transport and accommodation for rural families receiving treatment at a venue far from their home
- Financial issues
- Occupational problems
- School problems
- Food/clothing problems
- Assistance with daily routine
- Cultural barriers
- Identifying caregiver and family resources
Treatments for mild practical problems may include the following:
- Education
- Support groups
- Resource lists of available supports
Treatments for more severe practical problems may include:
- Counselling for patients and families
- Arranging support from community agencies
- Instruction or problem solving
- Patient advocacy
- Support groups
- Continuing education
Definition of supportive care during cancer:
‘…the provision of the necessary services as defined by those living with or affected by cancer to meet their physical, social, emotional, informational, psychological, spiritual, and practical needs during the prediagnostic, diagnostic, treatment and follow-up phases of cancer care, encompassing issues of survivor ship, palliation and bereavement.’
Risk factors of psychosocial distress:
- Being very old or very young
- Being single, separated, divorced or widowed
- Being female
- Having children younger than 21 years
- Those with poor marital functioning
- Having more advanced disease at diagnosis
- Having recurrent disease
- Having medical comorbidities
- Past psychiatric treatment, especially depression
The key principles of supportive care as discussed by Vic Gov (2009) are:
- A person centered (and family centered) approach to care
- A system wide and team approach, within services and sectors, to ensure all health care professionals have responsibility for supportive care
- Developing and supporting the workforce to optimise their capacity to respond to the needs of those affected by cancer
- Maintaining a focus on quality of care through providing evidence-based protocols and processes and monitoring progress and outcomes through medical record audit, bench marking and peer review
- Population based planning to identify the needs of the population and gaps in existing supportive care services and to facilitate an informed approach to future service planning
Barriers to the delivery of psycho social care:
- They do not have access to care (geographically)
- They lack either health insurance or coverage that includes mental health services
- They do not ask for help because of stigma
- Patient–provider miscommunication
- Failure to implement clinical practice guidelines
Cancer Cell Biology: Proliferation Growth Patterns
- A common feature of all cancers is the loss of cellular proliferation i.e. cancer cells are not subject to the usual restriction on cell growth and proliferation imposed by the host
- Normal cells acquire certain specialised characteristics of their tissue of origin i.e. differentiation
When does death from cancer usually occur?
At around 40 doublings
Tumour growth:
- From a single cell, cancer may take months/years to become detectable
- Doubling time is the time a tumour takes to double its size
What is Platelet-derived growth factor?
One of the numerous proteins that regulate cell growth and division
What is Epidermal Growth Factor?
A protein with 53 amino acid residues and three intramolecular disulfide bonds. It plays an important role in the regulation of cell growth and proliferation
What is Transforming Growth Factor?
Plays crucial roles in tissue development, cell differentiation, and embryonic development, as well as numerous other signalling pathways
What is Vascular endothelial growth factor?
An important signal protein involved in angiogenesis
The Metastatic Cascade (1-8):
- Tumour initiation
- Progression
- Proliferation
- Angiogenesis
- Invasion / Intravasation
- Extravasation
- Colony Formation
- Evasion of host defenses
What is apoptosis?
Apoptosis is the process of programmed cell death. It is used during early development to eliminate unwanted cells. Maintenance of healthy tissues and organs is dependent upon the proper balance of cell division with apoptosis.
Cancer staging systems:
- Location of Tumour
- Type of Cells (such as germ cells or adenocarcinoma)
- Tumour Grade (how abnormal cells look compared to normal cells)
- Measurement of tumour size
- Lymph node spread of tumour cells
- Metastatic spread to other sites
Most common staging system - TNM:
T (Tumor): Size and extent of primary tumor
N (Nodes): Number of nearby lymph nodes that contain cancer/cells
M (Metastasis): Spread to other sites and organs
Australian Clinico-Pathological Staging: Stage A
Cancer is found only in the bowel wall
Australian Clinico-Pathological Staging: Stage B
Cancer has spread to the outer surface of the bowel wall
Australian Clinico-Pathological Staging: Stage C
Cancer has spread to the lymph nodes near the bowel
Australian Clinico-Pathological Staging: Stage D
Cancer has spread beyond the lymph nodes to other areas, such as the liver or lungs
Cancer screening programs and ages:
- Breast Screen: Women > 40 yrs. Focus is 50-69 yr age group due to risk of breast cancer death for this age range
- National Bowel Ca Screening Program: People aged 50-74 yrs receive a FOBT approximately every 5 years.
- Cervical Screening: Changes now suggest if HPV screening test is negative, pap testing can be delayed and testing completed less frequently.
Reducing cancer progression - body changes:
Skin checks, BSE,TSE, urinary and bowel changes, prostate checks, physical assessments
Reducing cancer progression - modifiable risk factors:
Quit smoking, limit alcohol, eat for health, maintain a healthy body weight, exercise regularly, be Sun Smart
What is carcinogenesis?
The process by which normal, healthy cells transform into cancer cells.
Differentiation cancer cells:
Normal cells acquire certain specialised characteristics of their tissue of origin
Well differentiated cancer cells:
tumour cells reproduce these features well i.e. breast cells
Poorly differentiated cancer cells:
tumour cells reproduce these features poorly i.e. difficult to tell the cell of origin
Undifferentiated cancer cells:
Cannot tell, no maturation
When is a solid tumour usually palpable?
At approx 30 doublings
What are oncogenes?
The mutated form of proto-oncogenes
What are proto-oncogenes?
The normal growth promoting genes
In normal cells what are proto-oncogenes?
- Growth factor
- Cell survival genes
- Cell cycle controlling genes
