Cancer
Tissues that continue to grow and undergo mitosis in adulthood include
o Skin
o Hair
o Mucous membrane
o Bone marrow
o Linings of the organs
Tissues that don’t undergo mitosis in adulthood include (dead tissues are replaced by scar
tissues)
o Heart muscle
o Skeletal muscle
o Neurons
Neoplasia is any new or continued cell growth not needed for normal development or
replacement for dead and damaged tissues
o This can be benign or cancerous
o They develop from normal cells
Contact inhibition is part of cellular regulation that stops further rounds of cell division
Euploidy is having a complete set of chromosomes
Cancer development (Carcinogenesis)
Initiation
o First step; it’s a change in the gene expression caused by anything that can cause DNA
damage which leads to loss of cellular regulation (loss of suppressor gene or
enhancement of proto-oncogene)
o This phase causes excessive cell division
o It’s irreversible
, o If growth conditions are right, widespread metastatic disease can develop from just one
cancer cell
Promotion
o Enhanced growth of the initiated cell
o It is done by promoters such as insulin and estrogen
o It can cause the cell to divide more frequently
o Latency period is time between initiation and the development of an overt tumor
o Can range from months to years
Progression
o Continued change of a cancer, making it more malignant over time
o Detectable tumor is at least 1-cm tumor that has at least 1 billion cells
o Other factors must be there for this tumor to become a health problem
Develop its own blood supply
Make vascular endothelial growth factors (VEGF)
Tumor cells continue to divide
Some of the new cells can have more genetic mutations from the
original and initiated cells
Two types of mutations
o Driver mutation, provide cells with advantages
o Passenger mutation, don’t provide advantages
Metastasis
o Cancerous cells moving from the primary location to another site in the body
o They are also called secondary tumors
o Ex. When breast cancer metastasized to the bone and the lungs, it’s still a breast cancer
that is in the lungs and bones, not lung or bone cancer
o Two types
Bloodborne
Lymphatic spread
More common when primary tumors are located in areas rich with
lymph nodes
Cancer classifications
Cancer is classified according to the type of tissue from which they arise
Grading
o Classifies the cellular aspect of the tumor
o High grade means “poorly differentiated” and more aggressive
o Low grade means “well differentiated” and less aggressive
o Grading is very important for prognosis
Ploidy
o The description of the cancer cell by the number of chromosome and appearance
o Aneuploidy is the abnormal number of chromosomes that cancer cells exhibit
o The degree of aneuploidy increases the degree of malignancy
o Some chromosomal changes are associated with specific cancers
Tissues that continue to grow and undergo mitosis in adulthood include
o Skin
o Hair
o Mucous membrane
o Bone marrow
o Linings of the organs
Tissues that don’t undergo mitosis in adulthood include (dead tissues are replaced by scar
tissues)
o Heart muscle
o Skeletal muscle
o Neurons
Neoplasia is any new or continued cell growth not needed for normal development or
replacement for dead and damaged tissues
o This can be benign or cancerous
o They develop from normal cells
Contact inhibition is part of cellular regulation that stops further rounds of cell division
Euploidy is having a complete set of chromosomes
Cancer development (Carcinogenesis)
Initiation
o First step; it’s a change in the gene expression caused by anything that can cause DNA
damage which leads to loss of cellular regulation (loss of suppressor gene or
enhancement of proto-oncogene)
o This phase causes excessive cell division
o It’s irreversible
, o If growth conditions are right, widespread metastatic disease can develop from just one
cancer cell
Promotion
o Enhanced growth of the initiated cell
o It is done by promoters such as insulin and estrogen
o It can cause the cell to divide more frequently
o Latency period is time between initiation and the development of an overt tumor
o Can range from months to years
Progression
o Continued change of a cancer, making it more malignant over time
o Detectable tumor is at least 1-cm tumor that has at least 1 billion cells
o Other factors must be there for this tumor to become a health problem
Develop its own blood supply
Make vascular endothelial growth factors (VEGF)
Tumor cells continue to divide
Some of the new cells can have more genetic mutations from the
original and initiated cells
Two types of mutations
o Driver mutation, provide cells with advantages
o Passenger mutation, don’t provide advantages
Metastasis
o Cancerous cells moving from the primary location to another site in the body
o They are also called secondary tumors
o Ex. When breast cancer metastasized to the bone and the lungs, it’s still a breast cancer
that is in the lungs and bones, not lung or bone cancer
o Two types
Bloodborne
Lymphatic spread
More common when primary tumors are located in areas rich with
lymph nodes
Cancer classifications
Cancer is classified according to the type of tissue from which they arise
Grading
o Classifies the cellular aspect of the tumor
o High grade means “poorly differentiated” and more aggressive
o Low grade means “well differentiated” and less aggressive
o Grading is very important for prognosis
Ploidy
o The description of the cancer cell by the number of chromosome and appearance
o Aneuploidy is the abnormal number of chromosomes that cancer cells exhibit
o The degree of aneuploidy increases the degree of malignancy
o Some chromosomal changes are associated with specific cancers
