Neoplasia: Genetics and Environment Flashcards
(68 cards)
Define neoplasia.
Abnormal and uncontrolled growth of cells that might result in the formation of solid masses with distorted tissue architecture, so called tumors.
Such growth is typically a consequence of alterations of the cellular function, which by its turn can result in proliferative, invasive and metastatic potential.
Neoplasia is generally associated with genetic abnormalities. True or False?
True
Not all neoplasia result in solid tumors as it is the case of _________________ cancers.
hematological
Benign neoplasia typically present ___________ growth and the cells are contained at the origin tissue/organ being _______________ to metastasize to other locations
slow; unable
Distinguish neoplasia, tumor and cancer.
Neoplasia - Abnormal and uncontrolled growth of cells, which can be benign or malign.
Tumor - Refers to a ‘mass effect’/space-occupying lesion resultant from an increase of a certain tissue or region. Such can happen not only in the case of neoplasia, but also in consequence of inflammatory reactions or fluid accumulation.
Cancer - Synonym of malignant neoplasia.
What are the 7 main risk factors of neoplasia?
- Environmental factors
- Inherited Genetics
- Age
- Gender
- Ethnicity and race
- Viruses
- Complications from previous pathologies and/or comorbidities
Give examples of environmental factors.
- Radiation exposure (ionizing radiation is known to cause DNA damage)
- Chemical exposure (e.g. arsenic, asbestos, cadmium, formaldehyde, etc…)
- Tobacco and exhaustions gases (that might contain carcinogenic substances such as 7,12 Dimethylbenz(a)anthracene, DMBA)
- Alcohol consumption (alcohol is decomposed in the body into acetaldehyde, which damages DNA and hinders its repair)
Most cancers can pass between generations. True or False?
False. Most cancers can’t themselves be passed between generations. However, genetic alterations that might be associated to higher predisposition to develop cancer can be passed down.
Give examples of genetic alterations that might be inherited and lead to higher risk of developing cancer.
- BRCA1 or BRCA2 mutations, which increase the chance to develop breast cancer among others;
- HOXB13 mutations, associated to higher risk of developing prostate cancer;
- EPCAM mutations, often associated to Lynch syndrome and increased risk of developing colorectal cancer;
- BRIP1 mutations, associated to increased risk of ovarian cancer;
- TP53 mutations, associated to the Li-Fraumeni syndrome, increase the risk of developing cancers such as breast, colorectal, and sarcoma.
Age is one of the most important risk factors partially because with aging the immune system response become weaker and less efficient and because there is a gradual _______________ of cells and proteins. Moreover, with aging there is an increase of the genomic _____________ and there is a _______________ _______________ of a life-long exposure to environmental factors, occupational hazards and even viral infections.
deterioration; instability; cumulative effect
Some differences are seen between ethnic groups which can be a consequence of inherent ___________ _________, different life-style habits, exposure to ______________ _______________ ________________, or even cancer screening and health system’s access ________________.
genetic factors; different environmental contaminants; disparities
Some viruses, parasites and bacteria might ______________ the immune system, which leaves the body more ________________ to cancer-causing infections. Moreover, some virus may also interfere with normal signaling pathways involved in the cellular ___________ and _________________ check points.
weaken; susceptible; growth; proliferation
Give examples on how complications from previous pathologies and/or comorbidities can be a risk factor for the development of a neoplasia.
Type 2 Diabetes / Excess of insulin: It has been associated to an increased risk of developing several cancers, once insulin is known to promote cell division.
Obesity: It has been associated to an increased risk of developing breast, colorectal, endometrial, esophageal, kidney, pancreatic and gallbladder cancers. Typically associated to increased production of insulin (in response to inflammatory processes) and estrogen (produced by fat tissue), which trigger cell growth.
What are the main 3 classification systems?
Classification systems are based on:
- Prognostic: benign, malignant, borderline behaviour
- Histogenic: epithelial, mesenchymal or connective tissue, muscle, neural, hematologic, endothelial
- TNM: grading system based on the primary tumor type, the affection or not of lymph nodes and the presence or not of distant metastases.
Benign neoplasia form well-delimited masses. True or False?
True
Distinguish benign and malignant neoplasia in terms of cellular morphism, nucleus, mitosis and polarity.
Cellular morphism: normal/differentiated vs pleomorphism/anaplasia
Nucleus: normal vs hyperchromic; prominent nucleolus; elevated nucleus/cytoplasm ratio
Polarity: present vs absent
Other changes: giant cells and ischemic necrosis can occur in malignant neoplasia.
How is tumor size (T) assessed in the TNM classification system?
T-1: 0-2 cm
T-2: 2-5 cm
T-3: >5 cm
T-4: Tumor has broken through skin or attached to chest wall
How is lymph node status (N) assessed in the TNM classification system?
N-0: Surgeon can’t feel any nodes
N-1: Surgeon can feel swollen nodes
N-2: Nodes feel swollen and lumpy
N-3: Swollen nodes located near collarbone
How is metastasis (M) assessed in the TNM classification system?
M-0: Tested nodes are cancer-free
M-1: Tested nodes show cancer cells or micrometastasis
What are the 3 main phases of carcinogenesis?
- Initiation
- Promotion
- Progression
What are the processes that occur during the ‘progression’ phase?
Angiogenesis; migration; invasion; metastasis
During initiation, carcinogenic agents will induce DNA mutations and damage cells. Such lesions can either be repaired or reproduced. True or False?
True
Cells present surveillance mechanisms to monitor and control the normal cell cycle, controlling for instance the appropriated cell size and the replication and integrity of the chromosomes. Such monitoring is possible through cell cycle checkpoints. When do said checkpoints occur?
G1 checkpoint check for: nutrients, growth factors, DNA damage
G2 checkpoint check for: cell size, DNA replication
Metaphase checkpoint check for chromosome spindle attachment
At the cell cycle checkpoints, _______________ molecules can be activated to dictate the progression for the next phase of the cell cycle (_______________ and ____________-dependent kinases), and to hold or _______________ the cell cycle progression (__________________ protein (Rb), ______ and ______).
regulatory; cyclins; cyclin; interrupt; retinoblastoma; p53; p21
