Cancer Flashcards
Why is difficult to find out which gene mutations in cancers cells result in cancer growth
The cell replication in cancers has made so many errors that is hard to see which one attributed to cancer growth because there are also many mutations that are not a cause just a consequence
What is the difference in mutation between oncogenes and tumour suppressor genes
Mutation in one of the two chromosomes of a proto-oncogene can already lead to increased cell proliferation, while mutations in both copies of the tumour suppressor genes are required to prevent inhibition of cell cycle by products of these genes. The mutation in oncogene is therefore dominant and the mutation in tumour suppressor gene recessive.
How does the process of micro-evolution in cancer work
The cancer cells that have a proliferative advantages over other cells outcompete the normal cells and when more mutations occur even more advantaged cancer cells might outcompetes first tumour cells and outcompetes normal cells for resources even more.
What enzymes do malignant tumour cells secrete and what is its effect
Malignant tumour cells secrete proteases that break down the extracellular matrix and enable the tumour cells to migrate through tissue and grow through tissue architecture
Which two processes are inhibited in cancer cells
The programmed cell death after to much DNA damage and cell cycle arrest to repair DNA are inhibited in cancer cells, causing rapid cell cycles and replication where the cell makes many mistakes in DNA replication that causes mutations
What is the definition of a lesion
Region of the body that has suffered body due to injury or disease
What is the definition of a tumour
Any lump forming lesion in the body
What three causes can a tumour have
Tumour can be neoplastic, it can be hamartomatous and it can be inflammatory
What is a hamartomatous lesion
A hamartomatous lesion is a local benign malformation of tissue architecture
What is the definition of neoplasm
A tissue that has autonomous growth after escaping the constraints of cell proliferation
In what two categories can neoplasms be divided and what do both types do
Benign, local neoplasm that remains situated in tissue and do not invade surrounding cells, and malignant, which invades cells of surrounding tissue and/or metastasises to different locations
By which process do malignant neoplasms spread to other sites
Metastasis
How can you palpate if a breast cancer is likely to be benign or malignant
If lump in breast is clearly demarcated and can be moved, it is a benign non-invasive tumour, but when it is fixed to the muscle or skin and is not clearly demarcated it is probably a malignant invasive tumour
Which type of malignant cancers have a very low chance of metastasising
Skin cancers, melanomas
Which type of benign tumours can prove to be fatal
Benign tumours in the brain can press against brain regions carrying out vital body function and so lead to death
Are hamartomas architectural or cytological abnormalities
Hamartomas are architectural abnormalities, because the cell lack the dysplastic features that neoplasms do, they only form aberrant overgrowtg structures within tissues
What is a heterotopia
A heterotopia is when a structure of normal tissue is found in an abnormal location of the body
What are the primary and secondary descriptions of neoplasms
The primary description of a neoplasm depends on its cell origin, the secondary description determines if its a benign or malignant tumour
What does the suffix “oma” mean in neoplasms and what does this distinguish
Suffix “oma” means that neoplasm is benign and so its distinguishes malignant and benign tumours
What is transitional epithelium and where is it found
Transitional epithelium is also called uroepithelium and is epithelium that can change shape due to mechanical stress
How would neoplasms in epithelial tissues in squamous, glandular and transitional epithelium be called
A benign squamous epithelium neoplasm would be squamous epithelioma, malignant squamous carcinoma, a benign glandular epithelium neoplasm adenoma, malignant adenocarcinoma, a benign transitional epithelium neoplasm transitional epithelioma, malignant transitional carcinoma
How would neoplasms in connective tissue in smooth muscle and bone tissue be called
A benign smooth muscle neoplasm leiomyoma, malignant leiomyosarcoma, a benign bone neoplasm osteoma, malignant osteosarcoma
What are haematologic benign neoplasms called
This is very uncommon
What are teratomas, what do they consist of and where can they be found
Teratomas are tumours that consist of multiple cell types of three different germ cell layers, give rise to any tissue, both mature and immature, and are most commonly found in the ovaries and testicles
Are teratomas benign or malignant neoplasms
Teratomas can be both benign and malignant neoplasms
Which neoplasms with the suffix “oma” are always malignant
Lymphomas and melanomas are always malignant, hepatomas too but preferred name liver cell cancer
What are the four differences between benign and malignant tumours
Benign neoplasms does not invade surrounding tissue while malignant neoplasms do, benign tumours do not metastasise while malignant neoplasms do, benign neoplasms are very similar in morphology (well differentiated) to surrounding tissue while malignant neoplasm cells can be very aberrant, benign neoplasms have very similar tissue architectural structure to surrounding normal tissue while malignant neoplasms can have very different tissue structure from original tissue
What is carcinoma in situ
Most severe form of dysplasia before cancer, where very abnormal cells are found in tumour but do not invade surrounding tissues
What distinguishes dysplasia or carcinoma in situ from cancer
Cancer cells invade surrounding tissues, where dysplastic cells and carcinomas in situ do not
When does dysplasia turn into cancer
When dysplastic cells break through basement membrane of tissue and invade other tissues, it turns into cancer
What is the difference in nuclear-cytoplasmic ratio between normal cells and tumour cells
Dysplastic and cancer cells have much larger nuclei and smaller cytoplasm as compared to normal cells
What is the difference in mitosis between normal cells and tumour cells
Cancer cells may have abnormal mitosis, for instance tripolar mitosis, while normal cells have a bipolar mitosis
What is nuclear pleomorphism
The variety in nuclear shapes and sizes
How does the malignancy of a tumour relate to the architecture of the tissue
A malignant tumour resembles the tissue it originates from much less than a benign tumour does
Why is the prognosis of a patient with metastasised cancer much worse than with local cancer
Because surgery to remove the tumour is virtually impossible if the tumour has spread to multiple organs, and also because metastasises can differentiate and mutate differently and not respond to chemotherapy in the same manner
What are five routes by which cancers can spread
- The direct extension, where cancers directly invade architecture of surrounding tissue, 2. haematogenous, where cancer cells enter the blood stream at site of initial tumour and metastasise to a distant location, 3. lymphatic, where cancer cells enter the lymphatic system at site of initial tumour and metastasise to a distant location, 4. transcoelomic, where cancer cells metastasise through body cavities that are easy to migrate through such as pleural and peritoneal cavities 5. perineural, where cancer cells proliferate in or along nerves through tissues
What is iatrogenic spread of tumours
The spread of cancer cells through body through a medical procedure where cancer cells are by mistake dropped in surrounding tissues where they can proliferate
What is the response of the body to direct extension spread of tumour called
The stromal response
What are the three aspects of the stromal response to a tumour
The desmoplastic response, which produces collagen fibres around the tissue, angiogenesis, which increases formation of new vasculature around the tumour, and an immune response, which will try to destroy cancer cells
What is the desmoplastic response in direct extension of tumours
In the desmoplastic response, fibroblasts will produce a network of collagen fibres that cancer cells can use as scaffolding mechanism to spread throughout a tissue
Which blood vessels are often invaded in haematogenous spread of tumours
The capillaries and venules are often invaded, because those have thinner vessel walls and are hence easier to invade
What is the difference in route of metastasis between sarcomas and carcinomas
Carcinomas often first spread via the lymphatic system, while sarcomas spread via the blood circulation
What role does the location of a tumour play in preventing metastasis via lymphatic route
Where tumour is located determines which lymph node it will spread to first, so looking at draining lymph node to particular area of body can detect if metastases have taken place
What is transcoelomic spread of cancer and what are the two most common examples
In transcoelomic spread of cancer, cells metastasise through body cavities that are easy to migrate through such as pleural and peritoneal cavities, because there is a lot of movement and it always moist which decreases resistance.
What is the peritoneal cavity and how does this facilitate metastasis
The abdominal cavity that contains all abdominal organs. The organs in this cavity move a lot due to ventilation that causes changes in diaphragm and body movements that involve pressure to the abdomen. Additionally this is a very moist cavity which decreases resistance for metastasis.
In which tumour is perineural route of metastasis often seen
Hepatic cancer
What is TNM system and how does it assess stage of tumour spread
The system that assesses the severity and the stage of a cancer. It changes for every type of cancer and depends on the tumour size and invasion of local tissue, nodes invaded and presence of metastases
What are the two most important features in assessing tumour prognosis and what is the most important of the two
Grade, how well differentiated tumour cells are and stage, how far and how much tumour has spread. Stage is more important, but the two are very related.
