14.5 Clinical aspects of cancer Flashcards
How may a tumour affect the body?
- Compete with normal body cells for nutrients and energy transported in the bloodstream
- Return waste materials to the bloodstream, which the body must process and eliminate
- Secrete substances that affect the person e.g. adrenaline
- Grow so large that it can press against body organs, causing pain
- Block the function of a vital organ, causing death
What is xeroderma pigmentosum (XP)?
A rare pre-malignant condition as a result of a gene mutation, whereby the skin loses its ability to repair itself from exposure to UV light
What is solar keratosis?
A pre-malignant condition occurring from years of exposure to the sun. Skin becomes rough and scaly
What is vulval intra-epithelial neoplasia (VIN)?
Pre-malignant skin condition of the vulva, symptoms intense and persistent itch. Many linked to HPV
What is cervical intra-epithelial neoplasia (CIN)?
Pre-malignant cell changes that occur in the cervix
What is Barrett’s oesophagus?
People who suffer from gastro-oesophageal reflux disease (GORD) are at risk of developing Barrett’s oesophagus
What is the screening process for breast cancer?
Mammogram. In the UK, all women aged 50-70 and registered with a GP are automatically invited for breast screening every three years
What is the screening process for cervical cancer?
Smear test. All women between 25-60 are invited for screening every 3-5 years
What is the scale of cervical intraepithelial neoplasia (CIN)?
An abnormal test result will say:
CIN 1 - mild cell changes (mild dyskaryosis)
CIN2 - moderate cell changes (moderate dyskaryosis)
CIN3 - severe cell changes (severe dyskaryosis)
What happens if a patient has CIN2 or CIN3?
They will be referred for a colposcopy biopsy, and if necessary receive treatment
What is the screening process for bowel cancer?
Faecal occult blood (FOB) test. All men and women aged 60 to 74 are invited to carry out FOB test at home. Test will not establish bowel cancer, but indicates whether a colonoscopy is required
What is the screening process for prostate cancer?
Blood test to detect the level of prostate specific antigen (PSA). If PSA level raised, other tests used e.g. digital rectal exam (DRE), biopsy. No screening programme in UK
How are cancers staged?
Stage 1 - the tumour is still small and has not spread outside the original site
Stage 2 - the tumour is still localised, but is larger than stage 1. Stage 2 may also refer to a cancer that has spread to nearby lymph nodes, depending on the type of cancer
Stage 3 - a tumour which has spread into nearby tissues and cancer cells are detected in nearby lymph nodes
Stage 4 - a tumour which has spread more widely to other, often distant, organs. This is known as secondary cancer, or metastatic disease
What is tumour grading?
Describes how similar the cancer cells are to normal cells of the same type, and how abnormal the tissue looks under the microscope (histopathology). Can be described as high or low or 1-4; low grade cancer cells look most like normal cells
What is cancer grading based on?
How differentiated cells appear under the microscope. High grade cancer cells are undifferentiated and look least like normal cells
What are features of poorly differentiated cancer cells?
They have lost all of the features that characterise the tissue of origin: More mitochondria than a normal cell (to process the energy for growth) More ribosomes (as protein is needed for cell division) The nucleus may change in size and shape
What is anaplasia?
The reversion to undifferentiated, unspecialised cells; these are known to lead to the formation of cancer
Describe cell structures in cancer cells (e.g. mitochondria, ribosomes)
May be abnormal. May be detectable under microscope in biopsy of tumour
Describe cell membranes in cancer cells
Abnormal proteins on surface. These may be measurable in blood and can be used to identify specific tumours (tumour markers)
Describe protein synthesis in cancer cells
Increased; proteins are needed for mitosis
Describe DNA in cancer cells
Mutated. Mutations in proto-oncogenes or tumour suppressor genes are the likely cause of cancer
Describe cell proliferation in cancer cells
Uncontrolled, purposeless. The higher the proliferative potential of the cancer cells, the worse the probable prognosis for the patient
Describe cell differentiation in cancer cells
Less differentiated or undifferentiated. The less differentiated the cancer cell, the worse the probably prognosis for the patient
What is molecular pathology?
Utilisation of molecular and genetic approaches to diagnose disease. Refers to the analysis of proteins, DNA/RNA, and other biological molecules in the context of disease. Can be used to classify tumours and direct treatment
What does the time to death in cancer depend on?
- Rate of tumour growth
- Degree of metastasis and sites affected by metastases
- Rate of growth of metastases
- Whether or not the person is treated
