Oncology Flashcards
proto-oncogenes
–genes that control cell replication
–result in cell growth and proliferation
–when mutated, proto-oncogenes become oncogenes that stimulate constant, unrelenting cell proliferation and cell cycling
difference between regular and cancer cell cycles
regular = checkpoints/rest phase
cancer = no checkpoints/rest phase
consequences of no checkpoints in cancer cell cycle
–no DNA errors recognized
–no apoptosis
growth in cancer cells
–cancer cells disregard the growth inhibitors released by neighboring cells
–as these cells proliferate, they stack on top of each other, take over boundaries of organs, crowd out normal cells, and may break free and travel to other sites in the body
differentiation
the extent that neoplastic cells resemble normal cells both structurally and functionally
anaplasia
total cellular disorganization, abnormal cell appearance, and cell dysfunction
anaplasia and proliferation
more anaplastic = faster proliferation
differentiation with benign and malignant tumors
benign = well-differentiated; resembles tissue of origin
malignant = poorly differentiated; does not resemble tissue of origin
rate of growth with benign and malignant tumors
benign = progressive, slow
malignant = erratic, slow to rapid
local invasion with benign and malignant tumors
benign = cohesive cells, well-demarcated tumor, often encapsulated making it movable
malignant = invasive and infiltrating, surrounding normal tissue
metastasis with benign and malignant tumors
benign = none
malignant = frequent
tumor care with benign and malignant tumors
benign = no necrosis
malignant = can have necrotic core
what are tumor markers?
biologic substances
what type of substances make up tumor markers?
hormones, enzymes, antigens, genes
where can tumor markers be found?
blood, urine, CSF, tumor plasma membrane
what are tumor markers useful for?
screening or diagnosis
are tumor markers diagnostic of cancer?
not always
examples of tumor markers
–prostate specific antigen
–BRCA gene mutation
grade I malignant tumor
cells are well-differentiated
grade II malignant tumor
cells are moderately differentiated
grade III malignant tumor
poorly differentiated or anaplastic cells
staging (T)
tumor size, location, and involvement
staging (N)
lymph node involvement
staging (M)
metastasis to distant organs
T0
no evidence of primary tumor
TIS
tumor in situ
T1-4
progressive increase in tumor size or involvement
N0
no spread to regional lymph nodes
N1
spread to closest or small number of regional lymph nodes
N2
spread to most distant or numerous regional lymph nodes
M0
none
M1
yes
stage 1
confined to organ of origin
stage 2
locally invasive (> 3 cm tumor)
stage 3
regional spread
stage 4
spread to distant sites
four phases of carcinogens
–initiation
–promotion
–progression
–metastasis
initiation
mutation of genes, spontaneous or induced by carcinogenic agent
promotion
actively proliferating cells accumulate; reversible
progression
further mutation of cells; invasive with metastatic potential
metastasis
spread of cancer
tumor suppressor genes in cancer cells
–brake pedal
–normally function to restrain cell growth (apoptosis)
–can also become defective and lose the ability to inhibit cell growth and division = cancer formation
oncogenes
–gas pedal
–mutated = gas pedal stuck
–growth signal permanently on
p53 gene
tumor suppressor gene in cells that controls cellular apoptosis
carcinogens
–substances that cause development of cancer
–can alter cell DNA
–damage = cumulative
classification of carcinogens
–known
–probable
–possible
promoters
agents that promote development of cancer
examples of promoters
–diet
–alcohol
–tobacco
–hormones
viral induced cancer
always involve the activation of growth-promoting pathways or inhibition of tumor suppressors in infected cells
examples of viruses that can cause cancer
–HIV
–HPV
–Hep B
–Hep C
vascular endothelial growth factor
a substance that gives cancer cells the capability to develop new blood vessels
primary tumor
site of origin
secondary tumor
anywhere that is not the site of origin
–need nutrients and oxygen
–need access to blood
seeding
tumor erodes and sheds into body cavities
implantation
direct expansion of tumor into adjoining tissue
two primary routes of metastasis
(1) lymphatic
(2) vascular
lymphatic spread
–cells trapped in lymph nodes
–three possible scenarios:
(1) death
(2) dormancy
(3) flourish/proliferate
vascular spread
–spread by vascular drainage –> penetrate local veins
–first stop = liver
why is the liver often the first stop in vascular spread?
because the liver receives the most blood through the portal vein before it circulates through the body
what happens in the liver during vascular spread?
clumping, trapping, proliferating
angiogenesis
complete own blood supply
most common places for secondary tumors
–lungs
–bone
–liver
–brain
lung cancer common site of metastasis
bone, brain
colon cancer common site of metastasis
liver
breast cancer common site of metastasis
bone, brain, liver, lung
prostate cancer common site of metastasis
vertebrae
melanoma common site of metastasis
brain
lung cancer
–leading cause of cancer-related death
–early diagnosis is key to treatment
–most often in > 65 years
–African Americans more often affected
lung cancer etiology
–cigarette smoking**
–passive smoke
–COPD
–asbestos
–radon
–arsenic
–genetics
patho of lung cancer
–carcinogen overload
–genetic
–paralyze the cilia
–lesion development progresses to cancer
–activation of oncogenes
–deactivation of tumor suppressor genes
–rapid proliferation/destruction/invasion
non-small cell lung cancer
makes up about 85-90% of all lung cancers; slow-growing
small cell lung cancer
rapidly growing tumor that tends to metastasize quickly
s/s of lung cancer
–cough
–hemoptysis
–wheeze or stridor
–chest pain
–dyspnea
–weight loss
–excessive fatigue
–weakness
–hoarseness
–pneumonia-like secretions
–often asymptomatic
what might be the first sign of lung cancer?
paraneoplastic syndrome
paraneoplastic syndrome
too much of a specific hormone showing up somewhere it shouldn’t be
–ACTH secretion from lung
–ACTH chemically resembles MSH
–stimulates melanocytes, giving patients with lung cancer a tanned appearance
breast cancer
–most develop from lining in ducts
–overexpressed estrogen receptors
–overexpressed human epidermal growth factor receptor
risk factors of breast cancer
–age > 50
–prolonged reproductive life
–hormone replacement therapy
–obesity
–late childbirth
–nulliparous
–family hx of breast or ovarian cancer
–Ashkenazi Jewish women
–BRCA1 and BRCA2 mutation
procedures associated with BRCA genes
preventative mastectomy and oophorectomy
cancer risks associated with BRCA genes
–breast
–ovarian
–colon
–pancreatic cancer
–prostate cancer
s/s of breast cancer
–single tumor
–nontender tumor
–firm tumor
–irregular borders
–adherence to the skin or chest wall
–upper, outer quadrant of breast
–nipple discharge
–swelling in one breast
–nipple or skin retraction
–peau d’orange
–Paget’s disease of the breast
peau d’orange
a thickening of skin that resembles an orange peel
Paget’s disease of the breast
involves redness, crusting, pruritis, and tenderness of the nipple
cervical cancer risk factors
–smoking
–history of STDs
–HPV infection
–two or more lifetime sexual partners
–immunosuppression
–genetics
high risk HPV
causes persistent infection that progresses to cervical cancer
low risk HPV
condylomata (genital warts) but does not cause cervical cancer
cervical cancer clinical course
–long asymptomatic period
–abnormal pap = dx
colorectal cancer screening
beginning at age 50, all adults should have a colonoscopy every 10 years
polyps
tumorous mass that projects into the intestinal lumen
familial adenomatous polyposis
well-defined hereditary disorder that predisposes an individual to intestinal polyps
colorectal cancer risk factors
–obesity
–tobacco
–physical inactivity
–insulin resistance
–low fiber in diet
–high amount of animal fat in diet
–diets low in vit. A, C, and E
–UC
–heavy alcohol use
s/s of colorectal cancer
–fatigue
–weakness
–weight loss
–iron deficiency anemia
–changes in bowel habits
–melena
–diarrhea
–constipation
–hematochezia (rectal bleeding) and narrowing of stool caliber