Cancer Flashcards
Define Cancer
Highly invasive and destructive neoplasms - Cells formed from irreversible deviant cell division
Define Tumour
Tumour is a collection of cells that have lost genetic control of proliferation and differentiation
What is a benign tumour
Localised and closely resembling cells of origin, but lost control of proliferation
suffix –oma to tissue type that the growth originated from e.g.
- Epithelioma – benign tumour of squamous epithelium
- Adenoma – benign epithelial neoplasm of glandular tissue
- Fibroma – benign tumour arising from fibrous tissue
Characteristics of benign tumour
- Differentiated cells
- Similar to normal cells
- Mitosis fairly normal
- Relatively slow growth
- Expanding mass
- Frequently encapsulated
- Remains localised
- Systemic effects-rare
- Only life threatening in certain locations (e.g. brain)
Define malignant tumour
Invasive and destructive cells that do not resemble cells of origin
suffix – carcinoma (epithelial) or sarcoma (connective tissue) e.g.
1. Adenocarcinoma - malignancies originated from gland like structures
2. Fibrosarcoma – a cancer of fibrous tissue
NB Lymphoma, melanoma, leukaemia, hepatoma are all malignant
Characteristics of malignant tumour
- Cells vary in size & shape, large nuclei
- Many undifferentiated cells
- Mitosis increased & atypical
- Rapid growth
- Cells not adhesive, infiltrate tissue
- No capsule
- Invades nearby tissue or metastatises to distant sites through blood & lymph vessels
- Systemic effects-often present
- Life threatening by tissue destruction & spread of tumours
State the 3 stages associated with the development of cancer
The initiating event causes a mutation in a cell, changes in the cell DNA. This initial change does not create an active neoplasm. The initiating event may eventually be indentified but many times it is not.
The promoting event is an expansion of the mutated cell’s growth and reproduction. Exposure to “promoters” later causes further changes in DNA, resulting in less differentiation and an increased rate of mitosis
The continued growth of the cell depends on continued exposure to the promoter. Dysplasia (presecence of abnormal cells) or anaplasia (cells that have lost their identity) may be evident at this time. This process leads to development of the tumour.
A common cancer promoter is chronic inflammation. Others include hormones and chemicals in the environment.
Progression is an extension of the promoter stage with one exception: now the cancer growth is no longer dependent on exposure to the promoter. The growth now becomes autonomous. The cell is capable of functioning outside of the rules that regulate cell growth, division and death.
Imitation agents
Oestrogen Red & processed meat Smoking Alcohol Obesity UV rays
Types of carcinogens
Lots of different types but the main ones are:
High energy ionizing radiation - gamma-rays, X-rays, UV rays, Cause genetic damage in a cell, Can kill cells directly
Hormones - Some tumour cells are responsive to hormones for growth, Ca of breast, uterus, prostate, adrenal glands
Chemicals - Tobacco (lung, laryngeal, lip, oesophageal, bladder Ca), Asbestos, benzene, insecticides, formaldehyde
Viruses & bacteria - HPV, hepatitis B or C, retroviruses (e.g. HIV), Helicobacter pylori
The spread of cancer
Once there is a neoplasm it can spread in different ways:
Local spread - Proliferation of the neoplasm within the tissue of origin
Direct extension - Process of tumour cells moving into adjacent tissues and organs
Seeding - Malignant tumours move along membranes of peritoneal and pleural cavities, gaining easy access to organs within
Metastases - Neoplasms spread to distant sites by way of lymphatics or blood vessels
What is the organ tropism of different cancers
Organ tropism = The affinity of a primary tumour to a specific distant site
Colon Ca - liver Breast Ca - bone Lung Ca - brain Prostate - bone Malignant melanoma Ca - lung, liver, brain, lymph nodes
Warning signs of Ca
- Unusual bleeding or discharge anywhere in the body; in urine, faeces, vaginally (unless menstruation)
- Change in bowel or bladder habits
- A change in a wart or a mole
- I saw that does not heal (On the skin or in the mouth)
- unexplained weight loss – sign of advanced disease
- Anaemia on low haemoglobin, and persistent fatigue
- Persistent cough or hoarseness without reason
- A solid lump, Often painless, in breast or testes or anywhere on the body
General manifestations of Ca
- Systemic inflammatory and immune responses - unexplained Fever, Anorexia (loss of appetite), Weight loss (either from anorexia or increased metabolic rate)
- Increased metabolic rate - dramatic unexplained weight loss
- Paraneoplastic symptoms - Indirect changes in the body function; tumour releases a hormone that causes a problem elsewhere
- Local effects of tumour on neighbouring tissues
a. Occupies space – palpable mass, pain
b. Loss of function – constipation or diarrhoea (bowel) , shortness of breath or persistent cough (lung)
c. Changes in blood - cancer markers
S&S of breast Ca
- Change in size or shape
- Redness or a rash on the skin and/or around the nipple
- Discharge (liquid) that comes from the nipple without squeezing
- A swelling in your armpit or around your collarbone
- A lump or thickening that feels different from the rest of the breast tissue
- A change in skin texture such as puckering or dimpling (like orange skin)
- Your nipple becoming inverted (pulled in) Or changing its position or shape
S&S of prostate Ca
- Passing urine more frequently
- Getting up in the night
- Difficulties passing urine
- Urgency
- Leaking
- Blood in urine
- Raised PSA (prostate specific antigen) - blood test marker of prostate cancer
