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
In the four stage classification system, what is a stage 2 tumor?
Greater than 3 cm and locally invasive, local lymph node involvement
In the four stage classification system, what is a stage 3 tumor?
Spread to nearby structures and organs, large number of regional lymph nodes involved
In the four stage classification system, what is a stage 4 tumor?
Cancer has spread to distant sites
What are the 4 phases of carcinogenesis?
- Initiation
- Promotion
- Progression
- Metastasis
In the phases of carcinogenesis, what is the initiation phase?
The alteration / change / mutation of genes that arise spontaneously or after exposure to a carcinogenic agent
In the phases of carcinogenesis, what is the promotion phase?
Actively proliferating cells accumulate, this stage is reversible with chemo / radiation
In the phases of carcinogenesis, what is the progression phase?
Cells undergo further mutation, these cells tend to be more invasive with metastatic potential
How are the actions of tumor suppressor genes and oncogenes altered with cancer?
Tumor suppressor genes are turned off while oncogenes mutate into proto-ocogenes and get turned on without release
What is the specific tumor suppressor gene that controls apoptosis?
P53
What are carcinogens?
Substances that cause development of cancer and can alter cell DNA. The more exposure to this, the more damage that is done.
What are known carcinogens?
Tobacco, asbestos, alcohol, HPV virus, HIV virus, estrogen
What are probable carcinogens?
Not enough data to support that they may be the cause of cancer - EX: women who work night shift
What are possible carcinogens?
Insufficient evidence to make any statement for or against the development of cancer
What are promoters?
Agents that promote the development of cancer
EX: diet, alcohol, tobacco, hormones
What is angiogenesis with tumor cells?
Cancer cells secrete vascular endothelial growth factor, a substance that gives then the ability to develop new blood vessels
What is a primary tumor?
A tumor at the site of origin
What is a secondary tumor?
A tumor as a result of a primary tumor traveling to a distant site.
Will looks like primary site cells
What is seeding?
Tumor erodes and sheds into body cavities
What is implantation?
Direct expansion of the tumor to an adjoining tissue
Explain lymphatic spread of cancer:
Cancerous cells find their way into the lymph system, they become trapped in it. There are 3 possible scenarios: death of the cancer cell, dormancy, or proliferating. If the cancer survives being in the lymph system it will be able to spread from node to node around the body and get to distant sites.
Explain vascular spread of cancer:
Cancerous cells spread by vascular drainage by penetrating local veins and getting into circulation. The first stop is often the liver due to the portal system.
If the primary cancer is lung, what are the common sites of metastasis?
Bone, brain
If the primary cancer is colon, what are the common sites of metastasis?
Liver
If the primary cancer is breast, what are the common sites of metastasis?
Bone, brain, liver, lung
If the primary cancer is prostate, what are the common sites of metastasis?
Vertebrae
If the primary cancer is melanoma, what are the common sites of metastasis?
Brain
What are common causes of lung cancer?
Smoking
Passive smoke
COPD
Asbestos
Radon
Arsenic
Genetics
Radiation therapy to the chest
Pulmonary fibrosis
How do you determine pack years?
How long the patient has bee smoking (in years) X how many packs per day
How does smoking tobacco influence the lungs?
Carcinogen overload, paralyzes cilia, lesion development, activation of oncogenes, deactivation of tumor suppressor genes, rapid proliferation / destruction / invasion
Compare the two types of lung cancers:
Non-small cell lung cancer: slow growing
Small cell lung cancer: rapidly growing tumor that mets quickly
What are the clinical manifestations of lung cancer?
Cough
Hemoptysis
Wheeze / stridor
Chest pain
Dyspnea
Weight loss
Excessive fatigue
Weakness
Hoarseness
Obstructive accumulations of secretions that may appear as pneumonia
Can be asymptomatic if early enough
Paraneoplastic syndrome - may be first sign of lung cancer
What is paraneoplastic syndrome?
Involves a lung tumor that secretes ACTH
If a patient has paraneoplastic syndrome, what is the appearance of their skin?
Tanned
What are the risk factors for breast cancer?
> 50
Prolonged reproductive life
Hormone replacement therapy
Obesity
Late childbirth after 30
Nulliparous
Family hx
Ashkenazi jewish women
BRCA 1 or 2 gene mutation
BRCA 1 or 2 gene mutations increase the risk of developing what cancers?
Breast, ovarian, colon, pancreatic, prostate
What are the s/s of breast cancer?
Single tumor, firm and nontender, irregular boarder
Adherence to skin / chest wall
Upper, out quadrant of breast
Nipple discharge
Nipple / skin retraction
Peau d’orange
Paget’s disease - involves redness, crusting, itching, and tenderness of the nipples
What are the screening recommendations for breast cancer?
Women of average risk should be screened yearly from ages 45-54
Some people may start sooner based on risk
At 55 mammograms can be every other year
What are the risk factors for cervical cancer?
Smoking
Hx of STD
HPV infection
Two or more lifetime sexual partners
Immunosuppression
Genetics
What are the risk factors for colorectal cancer?
Obesity
Tobacco use
Physical inactivity
Insulin resistance
Low fiber in diet
High amounts of animal fat in the diet
Diet low in vitamin A, C, E
Ulcerative colitis
Heavy alcohol use
What are the s/s of colorectal cancer?
Fatigue
Weakness
Weight loss
Iron deficiency anemia
Changes in bowel habits
Melana
Diarrhea
Constipation
Lower bowel cancer can have hematochezia (rectal bleeding)
What are the barriers to success for cancer treatment?
Need to kill 100% of cancer cells
Late detection of cells
Tumor resistance
Drug resistance
Cell heterogeneity
What is intermittent chemo?
Doing chemo at intervals to let the normal cells recover but not waiting too long because they cancer will be able to recover too.
What are 2 things that combination chemotherapy reduces and 1 thing that is increases?
Reduces: drug resistance, normal cell injury
Increases: amount of cancer cells killed
What is regional therapy related to chemo?
Access to the tumor itself, doing high dose concentrations directly to the tumor
This decreases systemic toxicity
What are normal side effects 1-2 weeks after a round of chemotherapy?
Decreased WBC, RBC, and platelets, diarrhea, alopecia, fatigue, and pallor
What are the 3 major complications from chemotherapy targeting rapidly dividing bone marrow?
Neutropenia
Thrombocytopenia
Erthrocytopenia
What is the clinical significance of chemo having reproductive toxicity for both men and women?
Women - know risks to developing fetus if they are pregnant
Males - consider sperm bank
How can chemotherapy cause hyperuricemia?
Destroys cells and DNA which releases uric acid
What is growth fraction?
The ratio of proliferating cells to resting cells.
Does chemo work better on a higher or lower growth fraction? Why?
Higher, because chemo targets proliferating cells.
What is the typical growth rate for tumor growth?
Malignant tumors initially grow very rapidly but as they grow in size the rate of proliferation decreases.
Why are larger tumors harder to treat?
They have a low growth fraction and a necrotic core
Why are solid tumors harder to treat?
Low growth fraction, limited blood supply
