Characteristics of Neoplasia Flashcards
What makes a cell a “cancer cell”?
○ Unregulated cell division
○ Loss of safeguards against DNA damage
○ Avoidance of cell death (ie. apoptosis)
○ Tissue invasion
○ Angiogenesis
○ Ability to metastasize
Prior to this some thought cancer was contagious, while others thought it was
a metabolic problem
Tumor gene sequencing
T/F Mutations could be random or from exposure to carcinogens
T
Tumor Suppressor genes function normal
Restrain cell growth, DNA damage control, and regulation of cell life cycle - when
inactivated leads to loss of function
(The brake)
loss of function mutations
Proto-Oncogenescan mutate to Oncogenes
Proto-oncogenes have a role in cell regulation, proliferation and differentiation, and when mutated, this normal control is lost
(The gas)
Gain of function mutations
Tumor Suppressor Gene Example
p53
p53 function
Normally, a Tumor Suppressor Gene
codes for the p53 protein, which
recognizes DNA damage, inhibits cell
proliferation, and induces apoptosis
Passenger mutations
not functionally significant; they
simply arose by chance in a single cell that gave rise to an expanding clone
Driver mutations
small number of the mutations that alter the cell cycle and promote tumorigenesis
Point Mutation
○ Single nucleotide substitution, insertion or deletion
○ Point mutation can lead to faulty proteins due to loss of specific RNA expression, or could lead to loss of function of large sections of the chromosome
○ Usually requires several mutations to create cancer
DNA Amplification
Overexpression of a of an DNA sequence/gene product
Chromosomes themselves can be
rearranged via ____. What is an example?
translocation
Eg. Philadelphia chromosome in
Chronic Myeloid Leukemia (CML)
Tumor cells are said to be _____ compared to normal tissue
poorly differentiated
There is typically ”_____ genetic heterogeneity” found in tumor cells, compared to normal tissue
Less
Precision Medicine
Knowledge of the genetics of cancer and understanding at the molecular level has brought about fine-tuned, patient specific treatment
What is called ____ is actually a group of many diseases with multiple phenotypic and molecular characteristics
“breast cancer”
Neoplasia
“New Growth”
○ Abnormal or uncontrolled division of new cells or cells that fail to die when they should
Well vs. poorly differentiated
■ Well differentiated – looks mostly like normal cells
■ Poorly differentiated – barely resembles normal cells
Can exhibit a mass effect, and compress
surrounding tissue, but does not invade other
tissues (e.g. uterine fibroids, warts)
Benign
Unregulated cell growth with the ability to invade tissues
Malignant – “Cancer”
Provides insight on how the tumor arose
DNA Sequencing
Adenoma
glandular/epithelial tissue
Exceptions of “oma” cancers that are not benign
Lymphoma, Melanoma (melanocytes), Astrocytoma (astrocytes), Seminoma
(testicles)
Histological cancer stages
● Hyperplasia – An increase in the number of cells in an organ or tissue
● Dysplasia – The presence of abnormal cells within a tissue or organ
● Carcinoma in situ – “in the original place.” Abnormal cells that look like cancer, but haven’t spread/invaded surrounding tissue
● Malignancy
○ Anaplasia – undifferentiated cells with the loss of the mature or
specialized features of a cell or tissue
Anaplasia features
- Cellular Pleomorphism
- Hyperchromatic Nuclei
- Nuclear/Cytoplasmic Ratio
- Abnormal Mitotic Figures
Dysplasia
Disordered/abnormal
growth of tissues resulting from
chronic irritation or infection
In many cases, ____ this stage is considered precancerous
dysplasia
Example of dysplasia
Best example is the detection of
cervical dysplasia on PAP smears.
Cervical dysplasia can lead to cervical
cancer if left untreated
“high-grade dysplasia”
Carcinoma in Situ
Carcinoma in situ
○ Full thickness dysplasia of the epithelium
○ Abnormal cells that look like cancer, but
haven’t spread/invaded surrounding tissue
■ In many cases, considered precancerous
● Is often confused as cancer (because of
name), but it is dysplasia
Anaplasia microscopic findings
Undifferentiated cells with the
loss of specialized cell features (structural and functional)
1. Cellular Pleomorphism
2. Hyperchromatic Nuclei
3. Nuclear/Cytoplasmic Ratio
4. Abnormal Mitotic Figures
Cellular Pleomorphism
Variability in size and shape
Hyperchromatic Nuclei
Darker color
Nuclear/Cytoplasmic Ratio
■ Poor nucleus to cytoplasm ratio 1:1 (Normally 1:5)
■ Rapid growth, limited cytoplasm
Abnormal Mitotic Figures
More cells undergoing mitosis, errors in chromosome separation
Carcinoma
Derived from epithelial and “lining” tissues (ectoderm and endoderm)
■ Squamous cell carcinoma, renal cell carcinoma, adenocarcinoma
Sarcoma
Derived from mesenchymal (connective) tissue (mesoderm)
■ Osteosarcoma (bone)
■ Fibrosarcoma (fibrous tissue)
■ Liposarcoma (fat)
■ Rhabdomyosarcoma (skeletal muscle)
Malignant pediatric tumor of embryonic tissue
Blastoma
■ Retinoblastoma
■ Neuroblastoma
Blastoma exception in adults
Glioblastoma seen in older adults
Germ Cell Tumor types
■ Seminomas
■ Teratoma (rare, benign)
■ Teratocarcinoma (rare, malignant)
■ Non-Seminomas
– Embryonal Carcinoma
– Yolk Sac Tumor (most common)
– Choriocarcinoma (rare)
Angiogenesis
Gain access to circulation
T/F Metastatic tumor is the same type of cancer as the primary tumor.
T
Three main pathways for metastasis
○ Through the Lymphatics: Breast cancer notoriously spreads by invasion of the lymphatic drainage
○ Through the Bloodstream: Many types of cancers are capable of spreading by the vascular system. Tumor invades blood vessel, allowing tumor detachments to “drift away to faraway places”
○ Direct Extension of the Primary Tumor: For example, Renal Cell Carcinoma can invade the adrenal glands, simply due to proximity
