Cancer Flashcards
Describe cancer.
Cancer is a group of diseases caused by genetically altered cells that undergo uncontrolled and abnormal growth. These altered cells can form tumors (neoplasms) and potentially spread to other parts of the body. Cancer arises due to mutations in genes regulating cell growth, DNA repair, and apoptosis.
What are the differences between benign and malignant tumours?
Benign tumours:
Cells appear normal and are well-differentiated
Growth is self-limiting and non-invasive
Encapsulated and do not spread to other tissues
Malignant tumours (cancer):
Cells show anaplasia and poor differentiation
Growth is rapid, unregulated, and invasive
Can metastasize to distant tissues
How do proto-oncogenes contribute to cancer development?
Proto-oncogenes regulate normal cell growth. When mutated, they become oncogenes that promote unregulated proliferation and differentiation. Mutations or amplifications lead to overactive proteins and increased growth signaling.
What is the role of tumour suppressor genes in cancer development?
Tumour suppressor genes normally inhibit cell division, repair DNA, trigger apoptosis, and enhance immune detection. When both alleles are mutated or lost, these controls are removed, allowing unregulated cell growth.
What do DNA repair genes do and how are they involved in cancer?
DNA repair genes fix damaged DNA. When mutated, repair fails, and damaged DNA accumulates, increasing the risk of mutations that can lead to cancer.
Describe the process of metastasis.
Cancer cells detach from the primary tumour
Invade nearby tissues
Enter blood or lymphatic vessels
Travel to distant sites
Form secondary tumours (metastases)
Angiogenesis (formation of new blood vessels) supports tumour growth and spread.
List some risk factors that increase cancer development.
Genetic predisposition
Chronic inflammation and infection
Immunosuppression
Chemical exposure (e.g. tobacco smoke, asbestos)
Radiation (UV, ionizing)
Poor diet (e.g. high red/processed meat, obesity)
Alcohol
What are some generalized signs and symptoms of cancer?
Fatigue (most common)
Pain
Cachexia (muscle wasting)
Systemic symptoms depending on affected body systems
May also include nausea, weight loss, fever, or bleeding
What are the main cancer treatments?
Surgery: Removes part or all of the tumour
Radiation therapy: Destroys DNA in cancer cells
Chemotherapy: Uses cytotoxic drugs to kill dividing cells
Immunotherapy: Stimulates the immune system to attack cancer
Hormone therapy: Blocks hormone production or reception in hormone-sensitive cancers
Gene therapy: Introduces new genetic material to correct or destroy cancerous cells
