Cancer Flashcards
How does basal cell carcinoma spread?
It only spreads locally - never spreads to other parts of the body
What is the cure for basal cell carcinoma?
complete local excision
= cure
How are white blood cells involved in cancer?
white blood cells circulate round the body
and so will any tumour of white blood cells
How are lymph nodes involved in carcinoma?
carcinomas spread to the lymph nodes that drain the site of the carcinoma
How else can carcinomas spread?
Carcinomas can spread through the blood bone
What are the cancers that spread commonly through the bone?
Breast, prostate, lung, thyroid and kidney
What is the treatment plan for breast cancer?
Confirm diagnosis of breast cancer > Has it spread to the axilla? > Yes : Axillary clearance is needed No: Has it spread to the rest of the body? > Yes: Systemic Chemo is needed No: Surgery with or without axillary lymph node clearance
What could still be present if a tumour is completely excised?
Micro metastases could still be present
What is adjuvant therapy?
Extra treatment given after surgical excision e.g. radiotherapy to breast after lumpectomy
What is carcinogenesis?
The transformation of normal cells to neoplastic cells though permanent genetic alterations or mutations. A multistep process.
What does carcinogenesis apply to?
Malignant neoplasms
What is oncogenesis?
Applies to malignant and benign tumours
What is a carcinogen?
Agents known or suspected to cause tumours
Carcinogenic = cancer causing
Oncogenic = tumour causing
Act on DNA i.e. are mutagenic
What are the classes of carcinogens?
Chemical
Viral
Ionising and non-ionising radiation
Hormones, parasites and mycotoxins
Miscellaneous
What are the features of chemical carcinogens?
No common structural features
Some act directly
Most require metabolic conversion from pro-carcinogens to ultimate carcinogens
Enzyme required may be present or confined to certain organs
What are the features of viral carcinogens?
Viruses cause approx. 10-15% of all cancers
Most oncogenic viral infections don’t result in cancer
What are some DNA viral carcinogens?
Virus: Associated cancers:
Human Herpes Virus | Kaposi Sarcoma
Epstein Barr virus | Burkitt lymphoma
Hepatitis B virus | Hepatocellular carcinoma
Human papillomavirus | Squamous cell carcinomas of head, neck, penis, cervix, anus
Merkle cell polyomavirus | Merkle cell carcinoma
What are some RNA viral carcinogens?
Virus: Associated Cancers:
Human T-lymphotrophic virus | Adult T- Cell leukaemia
Hepatitis C Virus | Hepatocellular carcinoma
Radiant energy and cancer
UV Light:
Exposure to UVA or UVB increases risk of BCC, melanoma, Squamous cell carcinoma (SCC)
↑↑ Risk in xeroderma pigmentosum
What are some biological carcinogens?
Hormones
↑Oestrogen → ↑breast or mammary/endometrial cancer - reduce oestrogen by having kids
Anabolic steroids → hepatocellular carcinoma
Mycotoxins
Aflatoxin B1 → hepatocellular carcinoma
Parasites
Chlonorchis sinensis → cholangiocarcinoma
Shistosoma → bladder cancer
What are other miscellaneous carcinogens?
Asbestos, metals
What are some factors of the host that can affect cancer and carcinogens? RISK FACTORS
Ethnicity
Diet / Lifestyle
Constitutional factors - age, gender etc.
Premalignant lesions
Transplacental exposure
How can ethnicity affect carcinogens and cancer?
Increased oral cancer in South East Asia, due to reverse smoking and betal chewing (Paan)
Decreased risk of skin cancer for those with darker skin
How do constitutional factors affect cancer?
Inherited predisposition
familial polyposis coli (chr 5)
retinoblastoma (chr 13)
Age
incidence increases with age
Gender
breast cancer F:M = 200:1
How can lifestyle affect cancer?
Diet / Exercise
Excess alcohol use increases risk of cancers of the mouth, oesophagus, liver, colon and breast
Obesity increases risk of breast, oesophagus, colon and kidney cancer
Exercise reduces risk of colon and breast cancer
Sexual behaviour
Unprotected sex increases risk of HPV-related cancer (cervix, penis, oropharyngeal)
How can premalignant conditions affect your chance of getting cancer?
Identifiable local abnormality associated with increased risk of malignancy at that site e.g.:
Colonic polyps
Cervical dysplasia (CIN)
Ulcerative colitis
Undescended testis
What is leukaemia?
Cancer of the white blood cells
Leukaemia need what treatment?
Systemic chemotherapy - need chemotherapy in the whole body
Why do carcinomas spread to local lymph nodes?
Lymphatic vessels are very thin walled - easier for cancer cells to get in there and will drain into local lymph nodes
Nearest lymph nodes to breast?
Axillary lymph nodes
How do we confirm breast cancer diagnosis?
Needle core biopsy and send it to pathology - needs to be disorganised invasive carcinoma
CT can pick up things ….
that are 10mm or more in diameter - size limit though
Some tumours you cant see
To stop breast cancer after surgery you can give…
adjuvant anti-oestrogen therapy
What is cancer at its fundamental level?
genetic
Where does most of our cancer risk come from?
Environment
What is a neoplasm?
A lesion resulting from the autonomous or relatively autonomous abnormal growth of cells which persists after the initiating stimulus has been removed - a new growth
What is asbestos linked to?
Mesothelioma
What is basement membrane made from?
Thick collagen
What does in situ in cancer mean?
The cancer is still within the duct - there is a big band of collagen around the duct
How do we treat in situ cancer?
Excise the cancer
What is an invasive cancer/ carcinoma?
The cells have invaded the basement membrane
What is microinvasive carcinoma?
It has invaded the basement membrane but not very far
How do you treat microinvasive cancer in the cervix?
Treat it with excision
What is metastasis?
The process whereby malignant tumours spread from their site of origin to form other tumours at distant sites
What is proliferation?
Fast mitosis, when cell reproduces rapidly.
Process of metastasis?
1.Detachment of tumour cells from their neighbours
2.Invasion of the surrounding connective tissue to reach conduits of metastasis
3.Intravasation into the lumen of vessels
4.Evasion of host defence mechanisms, such as NK cells
5.Adherence to endothelium at a remote location
6.Extravasation of the cells from the vessel lumen into the surrounding tissue
7.Tumour cells proliferate in the new environment
Also look at Invasion and metastasis lecture for a decent explanation
What type of spread do carcinomas prefer?
Lymphatic spread
What type of spread do sarcomas prefer?
Hematogenous spread
Name of malignant tumour in striated muscle?
rhabdo myosarcoma
Which cancer does not commonly metastasise to bone?
Liposarcoma
What term describes a cancer that has not invaded the basement membrane?
Carcinoma in situ
Name of benign tumours in glandular epithelium?
Adenoma
What is colorectal screening?
Testing for blood in faeces - if positive then colonoscopy done - lots of polyps most of the time not cancer
What is breast cancer screening?
Mammography
What is cervical cancer screening?
Direct swab from cervix
What do aromatic amines cause?
Bladder cancer
What does aflatoxin cause?
Hepatocellular cancer
What is a tumour?
Any abnormal swelling e.g
Neoplasm
Inflammation
Hypertrophy
Hyperplasia
What is the structure of neoplastic cells?
-Derive from nucleated cells
-Usually monoclonal
-Growth pattern related to parent cell
Synthetic activity related to parent cell:
collagen, mucin, keratin, hormones etc
What is the neoplasm stroma?
connective tissue framework
mechanical support
nutrition
Why classify neoplasms?
To determine appropriate treatment
To provide prognostic information
Methods of classification?
Behavioural: benign/malignant
Histogenetic: cell of origin
Neoplasm may be classified as…?
benign
borderline
malignant
Describe a benign neoplasm?
Localised, non-invasive
Slow growth rate
Low mitotic activity
Close resemblance to normal tissue
Circumscribed or encapsulated
e.g. fibroid
What are features of a benign neoplasm?
Nuclear morphometry often normal
Necrosis rare
Ulceration rare
Growth on mucosal surfaces often exophytic
Why should we worry about benign neoplasms?
Because they cause morbidity and mortality:
Pressure on adjacent structures
Obstruct flow
Production of hormones
Transformation to malignant neoplasm
Anxiety
What is a description for malignant neoplasms?
Invasive
Metastases
Rapid growth rate
Variable resemblance to normal tissue
Poorly defined or irregular border
What does a high grade neoplasm mean?
It doesnt look like normal tissue - is a bad prognosis
What does a low grade neoplasm mean?
It doesnt look like normal tissue - good prognosis
What does a low grade neoplasm mean?
It doesnt look like normal tissue - good prognosis
What are the features of a malignant neoplasm?
Hyperchromatic nuclei – darker than normal
Pleomorphic nuclei – vary in size
Increased mitotic activity
Necrosis common – because It outgrows blood supply
Ulceration common
Growth on mucosal surfaces and skin often endophytic
How do malignant neoplasms attack and cause cancer
Encroach upon and destroy surrounding tissue
Are poorly circumscribed – tongues of them to surrounding tissue
Have a ‘crab-like’ cut surface (Latin: cancer)
Metastasise
Why should we worry about malignant neoplams?
They cause morbidity and mortality
Destruction of adjacent tissue
Metastases
Blood loss from ulcers
Obstruction of flow
Hormone production
Paraneoplastic effects – finger clubbing due to lung cancer
Anxiety and pain
What does it mean if a neoplasm is subclinical?
Patient doesnt know we have it
What is the structure of neoplastic cells?
Derive from nucleated cells
Usually monoclonal
Growth pattern related to parent cell
Synthetic activity related to parent cell:
collagen, mucin, keratin, hormones etc
What is the general structure of a neoplasm?
Neoplastic cells + Stroma
neoplastic cells derive from what?
Nucleated cells
What is the function of the stroma in a neoplastic cell?
connective tissue framework
mechanical support
nutrition
Stroma supports neoplastic cell
Rich in fibroblast
What is histogenesis?
the specific cell of origin of a tumour
Neoplasms can arise from what?
Epithelial cells
Connective tissues
Lymphoid/haematopoietic organs
What suffix do all neoplasms have?
“oma” at the end
What is the prefix dependent on?
behavioural classification and cell type
What is the nomenclature for a benign epithelial neoplasm of non-glandular, non-secretory epithelium
Papilloma - benign tumour of non-glandular, non-secretory epithelium
Prefix with cell type of origin e.g. squamous cell papilloma – almost always this
What is the nomenclature of a benign tumour of glandular or secretory epithelium?
Adenoma - benign tumour of glandular or secretory epithelium
Prefix with cell type of origin e.g. colonic adenoma, thyroid adenoma.
What is the nomenclature for malignant epithelial neoplasms?
Carcinoma - malignant tumour of epithelial cells
Prefixed by name of epithelial cell type e.g. urothelial Ca.
What is a carcinoma of glandular epithelium called?
Adenocarcinoma
What are some bening connective tissue neoplasms?
Named according to cell of origin, suffixed by ‘-oma’
Lipoma: adipocytes
Chondroma: cartilage
Osteoma: bone
Angioma: vascular – blood vessels
Rhabdomyoma: striated muscle
Leiomyoma: smooth muscle
Neuroma: nerves
What are some malignant connective tissue neoplasms?
Liposarcoma adipose tissue
Rhabdomyosarcoma striated muscle
Leiomyosarcoma smooth muscle
Chondrosarcoma cartilage
Osteosarcoma bone
Angiosarcoma blood vessels
What is the tumour called if the cell type is said to be unknown?
Anaplastic
What are some ‘-omas’ that are not neoplasms?
e.g. granuloma, mycetoma- growth of fungus in lung, tuberculoma – mass of inflamed infected tissue due to TB
Which malignant tumours arent carcinomas or sarcomas?
melanoma: malignant neoplasm of melanocytes
Mesothelioma: malignant neoplasm of mesothelial cells
lymphoma: malignant neoplasm of lymphoid cells
Which tumours were named after the person that first discovered them?
Burkitt’s lymphoma
Ewing’s sarcoma – bone cancer
Grawitz tumour – kidney cancer
Kaposi’s sarcoma - herpes
What is the behavioural classification of a benign tumour?
Does not invade the basement membrane
Exophytic (grows outwards)
Low mitotic activity
Circumscribed
Necrosis and ulceration rare
What is the behavioural classification of a malignant tumour?
Invade the basement membrane
Endophytic (grows inwards)
High mitotic activity
Poorly Circumscribed
Necrosis and ulceration common
What is histogenesis classification?
Based on the specific cell or origin of the tumour
Epithelial cells form carcinomas
Connective tissues form sarcomas
Lymphoid forms lymphomas or leukaemia
What is histological grading?
Grade is based on the extent to which the tumour resembles its original histology
Grade 1 – Well differentiated (most closely resembles parent tissue)
Grade 2 – Moderately differentiated
Grade 3 – Poorly differentiated
What are the routes of metastasis?
Bone metastasises from lung, breast, kidney, thyroid, prostate
Lymphatic metastasis is common (secondary tumours in lymph nodes)
Carcinomas prefer lymphatic spread
Sarcomas prefer haematogenous spread
What is tumour staging?
Staging is the extent of a tumours spread
Determined by histopathological examination and clinical examination
