TumourPath Flashcards
Type of tumour
- Benign
- Malignant. Ability to invade into adjacent tissue and to metastasise and and grow at other sites within body
Nomenclature of epithelium tumours
- Glandular:
Benign: adenoma and malignant: adeno-carcinoma - Squamous:
Benign: squamous papilloma and malignant: squamous carcinoma
Nomenclature of connective tissue tumours
- Bone
Benign: osteoma, malignant: osteo-sarcoma - Fat
Benign: lipoma, malignant: lipo-sarcoma
Nomenclature of blood tumours
- cells, not vessels
- Malignant: white blood cells, leukaemia
Nomenclature of lymphoid tissue tumours
Malignant: lymphoma
Nomenclature of neural tissue tumours
- Central nervous system: astrocytoma
- Peripheral nervous system: Schwannoma
Nomenclature of germ cell tumours
- Teratomas:
Tumour composed of various tissues - Ovarian, benign
- Testicular, malignant
Main features of benign tumours
- Non-invasive growth pattern
- Usually encapsulated
- No evidence of invasion
- No mets
- Cells similar to normal
- Tumours ‘well differentiated’
- Function similar to normal tissue
- Rarely cause death
Main features of malignant tumours
- Invasive growth pattern
- No capsule or capsule breached by tumour cells
- Cells abnormal
- Cancer are often poorly differentiated, don’t look anything like cells around it
- Loss of normal function
- Evidence of spread of cancer
- Can cause death
Properties of cancer cells
- Altered genetics
- Altered cellular function (tumour related proteins and loss of function)
- Abnormal morphology
- Cells capable of independent growth
Altered genetics of cancer cells
- Loss of tumour suppressor genes
- Gain of function of oncogenes
What can tumour biomarkers be used for?
You can pick up tumour-related proteins and used these for screening, diagnosis, prognosis and predictive (using a particular therapy)
Onco-fetal proteins examples
- Alpha-fetoprotein: teratoma of testis, hepatocellular carcinoma
Oncogenes
- Kras: colorectal cancer. (know for treatment type)
- Braf: melanoma
Growth factors and receptors and what cancer they’re related to
- Oestrogen receptor - predictive biomarker: breast cancer
- Prostate specific antigen: prostate cancer
- EGFR: lung cancer
- Her2 (EGFR related protein): Breast cancer and gastric cancer
Loss of cellular function in cancer cells
- Loss of cell-to-cell adhesion
- Altered cell-to-matric adhesion
Abnormal morphology
- Balance between cell growth and cell death
- Angiogenesis vs. apoptosis
- Angiogenesis is a route for release of tumour cells into circulation
- Apoptosis regulates cell growth
Angiogenesis is in favour in cancer
Types of cancer spread
- Local
- Lymphatic
- Blood spread
- Transcoelomic spread (thorax and abdo)
Local spread of cancer
- Malignant tumour spreads locallt and ends up in lymph or blood vessels
Lymphatic spread of cancer
- Tumour cells adhere to lymph vessels and invade the lymphatics
- Mets in lymph node, divide and grow
- This is when it becomes clinically evident
Blood spread of cancer
- Same concept as lymphatic
- Invade blood vessels, invade the tissue
- Metastasise, can line vascular endothelium if it is conducive to growth
Trans-coelomic spread
- Spread in body cavities, special form of local invasion
What influences where they metastasise to?
- blood flood
- tumour related factors
- host factors
Common sites of metastasis
- Liver (CRC)
- Lung
- Brain
- Bone: axial skeleton (breast, prostate)
- Adrenal gland
Local effects of benign tumours
- Pressure: can apply pressure to adjacent groups
- Obstruction: intestinal or urinal tract
- You can get pressure effects causing an obstruction
Local effects of malignant tumours
- Pressure
- Obstruction
- Tissue destruction: ulceration/infection. If exposed to microorganisms, you can get a secondary infection
- Bleeding: anaemia or haemorrhage
- Pain: pressure on nerves, perineural infiltration, bone pain in pathological fractures
- Effects of treatment
Systemic effects of cancer
- Secretion of hormones
- Weight loss: cachexia
- Paraneoplastic syndromes
- Effects of treatment
Secretion of hormones
- Normal: if tumour is in endocrine organs then it has an abnormal control of secretion
- Abnormal: hormones not normally produced at site. Can be useful in diagnosing lung cancer
Paraneoplastic syndromes
- fever, myopathy, neuropathy
- Can present with these symptoms rather than direct symptoms of cancer
- could be immune mechanism or production of hormone factor
Dysplasia
- Pre-malignant change on pathway to the development of cancer.
- Abnormality in cell structure that leads to malignancy
- Earliest change in the process of malignancy that can be visualised
- Identified in the epithelium
- Has the capability of becoming cancer
Features of dyplasia
- Disorganisation of cells: increase in nuclear size, increased mitotic activity, abnormal mitoses
- The higher that grade, the higher possibility of malignancy
- No invasion
Early detection of cancer
- Need an effective test
- Has to be sensitive/specific
- Acceptable to population
- Example: detection dysplastic cells from squamous epithelium of cervix
