Oncology Flashcards
What happens at the G0 stage of the cell cycle?
The cell is at rest and is not actively engaged in the cell cycle.
What happens at the G1 stage of the cell cycle?
Cell enters the cell cycle and prepares for DNA replication, proto-oncogenes are activated
What happens at the S stage of the cell cycle?
Synthesis of structures occurs and the structures move to opposite poles in preparation for division into two separate cells. The 46 chromosomes reorganize as two separate sets of 23 chromosomes pairs arranges at opposite poles. Two nuclear membranes develop around the two sets.
What happens in the G2 stage of the cell cycle?
Cells prepare to divide
What happens at the M stage of the cell cycle?
Mitosis is complete and two daughter cells are created
In what ways do cancer cells disregard the normal cell cycle rules?
Cancer cells do not go through checkpoints, so no DNA errors are caught and no apoptosis occurs as a result
They also disregard the growth inhibitors released by neighboring cells so they just overtake their space completely
Why does tumor development become easier with age?
The strength of the immune system diminishes.
In a normal healthy body the immune system constantly surveys for foreign substances and non-self substances, destroying it if it comes about. But as the immune system decreases, tumor development often goes unnoticed.
Define differentiation
The extend that neoplastic cells resemble normal cells structurally and functionally
(XYZ cell is well differentiated)
Define anaplasia
Lack of differentiation, indicates total cellular disorganization, abnormal cell appearance, and cell dysfunction
Compare the proliferation rate between normal cells and cancerous cells:
Normal = predictable
Cancerous = unpredictable and can be dependent on differentiation, the more anaplastic cells the faster they grow
What is the differentiation like in benign tumors vs malignant tumors?
Benign = differentiated, resembles the tissue of origin
Malignant = poorly differentiated, does not resemble the tissue of origin
What is the rate of growth like in benign tumors vs malignant tumors?
Benign = progressive, slow
Malignant = erratic, slow to rapid
What is the local invasion like in benign tumors vs malignant tumors?
Benign = cohesive cells, well-demarcated tumor, often encapsulated making it movable
Malignant = invasive and infiltrating, surrounding normal tissue
What is the tumor core like in benign tumors vs malignant tumors?
Benign = no necrosis
Malignant = can have necrotic core
What are tumor markers?
Biological substances that can be hormones, enzymes, antigens, or genes
Where can tumor markers be found?
Blood, urine, CSF, or on the tumor plasma membranes
What are tumor markers useful for?
Screening or diagnostic purposes, helps follow the clinical course of the cancer as the patient goes through treatment
Are tumor markers diagnostic of cancer?
Not always, some nonmalignant diseases can also produce elevated levels but the markers are still generally helpful
What are two examples mentioned about types of tumor markers?
Prostate specific antigen (PSA) and BRCA gene mutation in r/t breast cancer
Define grade I malignant tumors:
Cells are well differentiated
Define grade II malignant tumors:
Cells are moderately differentiated
Define grade III malignant tumors:
Cells are poorly differentiated or are anaplastic
How many grades in the TMN system are there?
3
What does the TNM stand for, in the TNM system?
T = tumor size, location, and involvement
N = lymph NODE involvement
M = metastasis to distant organs
Does a TNM system classification require a biopsy?
Yes
In the TNM system for tumor classification what does T0 refer to?
No evidence of primary tumor
In the TNM system for tumor classification what does T1S refer to?
Tumor in situ (means early stages, still in the first layer of the cells in which the cancer originated)
In the TNM system for tumor classification what does T1-4 refer to?
Progressive increase in tumor size or involvement
In the TNM system for tumor classification what does N0 refer to?
No spread to regional lymph nodes
In the TNM system for tumor classification what does N1 refer to?
Spread to closest or small number or regional lymph nodes
In the TNM system for tumor classification what does N2 refer to?
Spread to most distant or numerous regional lymph nodes
In the TNM system for tumor classification what does M0 refer to?
No metastasis
In the TNM system for tumor classification what does M1 refer to?
Metastasis present
In the four stage classification system, what is a stage 1 tumor?
Tumor is small, limited to the organ or origin with no lymph involvement