cancer (test 1) Flashcards
What is cancer?
Cancer is a group of diseases caused by changes in cell DNA, making the cells grow out of control and form lumps called tumours. These tumours can be harmless (benign) or harmful (malignant).
What’s the difference between benign and malignant tumours?
Benign tumours: Grow slowly, stay in one place, and have normal-looking cells.
Malignant tumours (cancer): Grow fast, invade nearby tissues, and can spread (metastasise) to other parts of the body. These cells look abnormal and don’t follow the body’s usual rules for cell growth.
How do certain genes cause cancer?
Cancer can start when specific genes change or mutate. There are 3 main gene types involved:
Proto-oncogenes: Control normal cell growth. When mutated, they become oncogenes, which make cells grow too much.
Tumour suppressor genes: Stop cells from dividing or make them self-destruct. If these are turned off, cancer can grow.
DNA repair genes: Fix DNA damage. If they don’t work, the damage stays and can lead to cancer.
What is metastasis?
Metastasis is when cancer cells break away from the original tumour, travel through blood or lymph, and form new tumours in other parts of the body.
What increases the risk of getting cancer?
Genetics: Some people inherit faulty genes.
Weak immune system
Chronic inflammation or infections
Chemicals: Like tobacco smoke, alcohol, asbestos
Radiation: Like UV from the sun or X-rays
Diet and obesity: Processed meat, high fat, low fruit/veg
What are some general signs and symptoms of cancer?
Signs depend on the type of cancer, but common ones include:
Feeling very tired (fatigue)
Pain
Weight loss (cachexia)
Other symptoms depend on where the cancer is in the body
What are some ways to treat cancer?
Surgery: Removes the tumour
Radiation: Destroys cancer cells using high-energy rays
Chemotherapy: Uses strong drugs to kill fast-growing cells
Immunotherapy: Boosts the immune system to fight cancer
Hormone therapy: Blocks hormones that help some cancers grow
Gene therapy: Fixes or changes genes inside cancer cells
Restoration of telomeres:
increases the chance of the immune system fighting cancer cells
occurs in cells forming benign tumours
decreases the likelihood of cell damage/death occurring in cancer cells
is a key aspect of chemotherapy treatment for cancer
decreases the likelihood of cell damage/death occurring in cancer cells
One of the cellular changes that occurs with cancer cells is the ability to restore telomeres, whicj essentially increases the life span and cell dividing ability of cells (potentially indefinitely!). In normal cells, telomeres shorten and when they get too short, a cell can no longer grow and divide.
Metastasis is:
the unregulated growth of cancer cells
the spread of cancer cells to other areas of the body
the transition of a benign tumour into a malignant tumour
the growth of new blood cells to supply a tumour
The spread of cancer cells to other areas of the body
Which of the following is the most commonly reported symptom associated with cancer?
Fatigue
Pain alleviated with rest
Dizziness
Nausea
Fatigue
While any of these symptoms may be experienced in relation to particular cancers, fatigue is the most common symtoms reported for caners across the board.
Which of the following cancer treatment options uses vectors (e.g. viruses) to introduce material into cells?
Hormone therapy
Gene therapy
Immunotherapy
Chemotherapy
Gene therapy
Vectors are used to introduce genetic material into cells to make alterations to cell processes, division and/or susceptibility to other treatments
Chemotherapy:
uses chemicals that enhance immune system cell action to fight cancer cells
is never curative
uses cytotoxic drugs to disrupt or prevent cell growth & division of rapidly/actively dividing cells
is most effective when only a single chemotherapy drug is used
Uses cytotoxic drugs to disrupt or prevent cell growth & division of rapidly/ actively dividing cells
These cytotoxic drugs are non-selective, so in addition to the cancer cells being affected, other normal body cells that regularly divide are also affected.
What are proto-oncogenes and how are they implicated in cancer development?
If these genes get changed (mutated), they can turn into oncogenes, which cause cells to grow and divide too much. These changes can also lead to extra copies of certain parts of DNA, like the parts that tell cells to grow.
What are tumour-suppressor genes and how are they implicated in cancer development?
Tumour suppressor genes are a class of genes coding for proteins which;
-Slow/stop cell divsion
-Initiate DNA repair
-enchance immune agaist cancer cells
-Trigger cellular apoptosis
Mutations (of both alleles) in these genes remove these controls, allowing unregulated cell growth & divison.
What is the difference between tumor grading and cancer staging.
Tumour grading compares the tumour cells to the host tissue cells and awards a grade based on the level of resemblance.
Cancer staging is about the size of the tumour and level of spread.
In both cases the higher the grade/stage, the more severe the cancer.
What do the letters TNM stand for in this cancer staging system?
T; size & extent of the tumour
N; Number of lymph nodes with cancer
M; Whether or not metastasis has occurred
Why might side effects like hair loss, reduced blood cell counts and GI tract damage & nausea/vomiting occur with chemotherapy?
Because active and rapidly dividing cells are targered by chemotherapy deug- including epithelial cell of the cell skin, including hair follicles, epitherlial lining of the GI tract, and developing blood cells (in bone marrow).
What are the key factors of benign tumours.
-Self-limiting cell growth
-tumour is encapsulated
-does not metasise
-cells appear normal
What are the key factors of melignant tumours?
-unregulated & rapid cell growth
-abnormal tissue arrangement
-ability to metastasise
-lack of cellular differentiation
-cells do not appear normal
Cancer risk factors
-Chronic inflammation
-Obesity
-Uv exposure
-Tobacco use
-Certain infections
-Diet high in red & processed meats and/or fats
-Certain air pollutants
