Disorders of Cell Growth Flashcards
What is a tumour?
An abnormal growing mass of tissue whose growth is not coordinated with that of the surrounding tissue.
What is a malignant tumour?
A tumour what can invade into adjacent tissue to metastasise and grow at other sites within the body
What are the top 5 overall cancers?
- Breast
- Lung
- Prostate
- Colon
- Melanoma
What are the top 5 male cancers?
- Prostate
- Lung
- Colon
- Bladder
- Lymph node
What are the top 5 female cancers?
- Breast
- Lung
- Colon
- Uterine
- Ovarian
How are tumours classified?
Benign vs malignant
Tissue of origin
What is a benign tumour of the glandular epithelium called?
Adenoma
What is a Benign tumour of squamous epithelium called?
Squamous papilloma
What is a malignant tumour of glandular epithelium called?
Adenocarcinoma
What is a malignant tumour of squamous epithelium called?
Squamous carcinoma
What is a benign tumour of bone called?
Osteoma
What is a benign tumour of fat called?
Lipoma
What is a benign tumour of fibrous tissue called?
Fibroma
What is a malignant tumour of bone called?
Osteosarcoma
What is a malignant tumour of fat called
Liposarcoma
What is a malignant tumour of fibrous tissue called?
Fibrosarcoma
What is a malignant tumour of leukocytes called?
Leukaemia
What is a malignant tumour of lymphoid tissue called?
Lymphoma
What is a malignant tumour in the CNS called?
Astrocytoma
What is a benign tumour in the PNS called?
Schwannoma
What is a teratoma?
A tumour of the germ cells
Are ovarian teratomas normally malignant or benign?
Benign
Are testicular teratomas normally malignant or benign?
Malignant
Note some of the properties of cancer cells
• Altered genetics ○ Loss of tumour suppressor genes ○ Gain of function of oncogenes • Altered cellular function ○ Tumour-related proteins • Abnormal morphology
• Cells are capable of independent growth • Loss of cell-to-cell adhesion • Altered cell-to-matrix adhesion • Production of tumour-related proteins Tumour biomarkers
What are tumour biomarkers?
Tumour related proteins
What is an oncofoetal protein?
A protein which shows expression in foetal cells, is switched off postnatal, and turned on in cancer.
How can tumour biomarkers be used clinically?
For screening
To aid in diagnosis
For prognosis (i.e. predict likely outcomes)
Prediction: identify patients who will respond to a particular therapy
Give examples of specific biomarkers and the cancers they are associated with.
Alpha-foetoprotein
- Testicular teratoma
- Hepatocellular carcinoma
Carcino-embryonic antigen (CEA)
-Colorectal cancer
Oestrogen receptor
-Breast cancer
Prostate specific antigen (PSA)
-Prostate cancer
How do cancer cells appear?
Have celllular and nuclear pleomorphism (variation in appearance)
Mitoses present and often abnormal
What are four modes of cancer spread?
Local spread Lymphatic spread Blood spread Trans-coelomic spread -(spread of cells across body cavity)
Describe metastasis via lymphatics
Adherence of tumour cells to lymph vessels
Invasion from lymphatics
Invasion into lymph node
Formation of mets in lymph node
Describe metastasis via blood
Adherence of tumour cells to blood vessels
Invasion from blood vessels
Invasion into tissue
Formation of mets
List common sites of metastasis (5)
Liver Lung Brain Bone (axial skeleton) Adrenal gland
What are the local effects of benign tumours?
Pressure
Obstruction
What are the local effects of malignant tumours?
Pressure
Obstruction
Tissue destruction (ulceration/infection)
Bleeding (anaemia, haemorrhage)
Pain (pressure on nerves, perineural infiltration, bone pain from pathological fractures)
Side effects of treatment
What are the systemic effects of malignant tumours?
Secretion of hormones
- Normal (produced by tumour of endocrine organ, abnormal control)
- Abnormal (produced by tumour of a non-hormone producing organ)
Weight loss (cachexia)
Paraneoplastic syndromes
Side effects of treatment
How can cancer be detected at a pre-invasive stage?
Identification of dysplasia (enlargement)/intraepithelial neoplasia
What are the features of dysplasia?
Disorganisation of cells
- Increased nuclear size
- Increase mitotic activity
- Abnormal mitoses
Describe the mechanism of action of alkylating agents
Covalently bonds with both strands of DNA preventing replication
Describe resistance mechanisms in cells to alkylating agents
Decreased entry or increased exit of a drug into/out of cell
Inactivation of drug
Enhanced DNA repair
Give an example of an alkylating agent
Cisplatin
Describe the mechanism of action of antimetabolite drugs (NB two methods)
Similar structure to metbolites needed by cell, can be incorporated into new nuclear materia or bind irreversibly with enzymes to inhibit mitosis
Give example(s) of antimetabolite drugs
Fluorouracil
Methotrexate
Mercaptopurine
Describe the mechanism of action of vinca alkaloids
Prevent spindle formation
Give an example of a vinca alkaloid
Vincristine
Describe the mechanism of action of taxoids
Prevent disassembly of spindles
How do certain antibiotics act against cancer?
Inhibit DNA/RNA synthesis
Give an example of an anticancer antibiotic
Bleomycin
Note two other anticancer chemotherapy options
Hormones (eg tamoxifen for breast cancer)
Immunotherapy