Cancer Flashcards
Cancer
The abnormal uncontrolled multiplication of cells due to genetic (DNA) mutations that disrupt the cell cycle
- eventually forms neoplasms (tumours) that can spread
Death from cancer occurs when a major organ or system in the body is affected (e.g. lungs) to the point where organ function is significantly compromised
Tumours
Groups of abnormal cells that form lumps or growths.
Benign tumours - do not spread
malignant tumours - spread and can be life-threatening
Malignant tumours can invade blood or lymphatic vessels and spread to distant sites and produce secondary tumours; this is called cancer metastasis
Carcinogens
Agents that cause damage, which causes mutations to genetic material
Causes of cancer
- carcinogenic chemicals
* ethanol, nickel, benzene, aflatoxins - Radiation
* ultraviolet, X-ray - Pathogens
* HPV, H. Pylori bacterium
Matastasis
When a pathogen spreads from an initial or primary site to a different or secondary site within the host’s body
Types of cancer
- Skin (non-malignant, nearly all cured)
- Breast
- Prostate
- Lung
- Colorectal
- Uterine, cervical, ovarian (Females)
- Bladder (Males)
Skin cancers
Most are carcinomas; grow slowly but easy to treat
- malignant melanoma is the rarest but most deadly form of skin cancer
Risk factors include: freckles, easily sunburned, family history of melanoma, large number of moles
Melanoma is 20x more common in light-skinned (white) individuals
Breast cancer
Risk factors:
* age
* genetics
* age at onset of menstruation
* lifetime exposure to menstruation
Dangerous when it metastasizes
(E.g. via lymph nodes near breasts)
Screening: mammograms
Treatment: surgery, radiation, chemotherapy
Cancer treatment: surgical removal
Oldest type of cancer treatment, and is effective against many types of
Lung cancer
Leading mortal cancer in Canada
* smoking is the #1 risk factor
Only 20% survive after 5 years
Prostate Cancer (males)
Walnut-sized gland near the bladder
- most common cancer in males (after non-malignant skin cancer)
Often asymptomatic
Risk factors:
- age
- obesity
- history of STIs
- diets (maybe)
Common symptom: changes in urinary frequency or flow
Treatment options:
* surgery to remove prostate
* radiation, cryotherapy, drugs
Colorectal cancer
Begins with polyps, which may progress through several stages and become cancerous
Polyp: small clump of cells that forms on the linings of the colon.
Screening: endoscopy
Incidence of colorectal cancer has been increasing in people in their 20s and 30s
Risk factors: older age, male sex, inflammatory bowel disease and family history; obesity
Symptoms:
* change in bowel movements
* pain/tenderness in abdomen
* blood in feces
Cervical cancer (females)
Cervix is between uterus and vagina
HPV causes 99% cervical cancers
* transmitted through skin contact
Screening: regular pap tests aid early detection of pre-cancerous cells
Screening
Involved general examinations (e.g. mammography) done on apparently healthy populations to identify those who may potentially have a disease
Testing
Done on those who believed to have a disease. It involves more specific tests (e.g. biopsies, microscopic examinations) to more thoroughly identify the presence of a disease
- testing is more invasive, time consuming, and costly than screening