Cell Growth and Neoplasia (complete) Flashcards
Discuss the key concepts of normal cell growth and differentiation control
- Overall, highly orchestrated and regulated process
- Results in formation of specialized tissues, organs, etc.
For multicellular organism — Dramatic changes in cell…
1) proliferation
2) death
3) differentiation
4) migration
5) also, cell-cell interactions
Humans = more static
Normal homeostasis is different in different tissues. What are 3 types of “normal” homeostasis
1) Continuously dividing
2) Quiescent tissues/cells
3) Non-dividing tissue/cells
Which areas are continuously dividing? Describe this.(homeostasis)
- Skin
- Gut epithelium
- Hematopoietic system
Constant turnover — commonly causes cancer b/c of high freq of division
Increased likelihood of error
Which areas are quiescent tissues/cells? Describe this. (homeostasis)
- Liver — hepatocytes (can regrow w/ damage)
Normally little turn over
Capacity for proliferation if needed
Which areas are non-dividing tissues/cells? Describe this. (homeostasis)
- CNS neurons
- the heart!
Little to no capacity for proliferation — terminally differentiated
Define hypertrophy. Give examples.
- Increase in cell size
- May be reversible
- Physiologic: e.g. pregnant uterus!!
- Pathologic: e.g. hypertensive cardiac hypertrophy… oh boy
Define hyperplasia. Give examples.
- Increase in cell #
- Drive by hormones/GFs
- May be reversible
- May predispose neoplasia
- Physiologic: e.g. breast when preggers/puberty
- Pathologic: e.g. endometrium
Define metaplasia. Give examples.
- Change from one benign, differentiated cell type to another
- Usually b/c of injury/inflammation
- May predispose neoplasia
Examples:
1) Bronchus (columnar to squamous — b/c of smoking)
2) Esophagus (squamous to columnar — b/c of acid reflux)
Define dysplasia. Give examples.
- Disordered growth
- Signifies early premalignant neoplasia in epithelia
- GIVEN A GRADE!
Characteristic histo features:
1) loss of cytologic uniformity
2) loss of normal histologic maturation
3) loss of architectural orientation
Couldn’t find examples
Define neoplasia. Give examples.
Think tumor
- New formation
- Progressive, unchecked ^ in cell #
- Has a clonal process
- Pathologic and irreversible :(
- Inherited or acquired
Define tumor. Give examples.
- Generally synonymous w/ neoplasm
Do you really need examples??
Define and describe malignant neoplasms
- Invade and metastasize
- CANCER!!!
- Causes injury to both local and distant tissues
- Invasive to adj tissues
- Necrosis!
GO LOOK AT A HISTO SLIDE! know what it looks like
Define and describe benign neoplasms
- Don’t invade or metastasize
- Cause injury by compression/interference w/ surrounding tissue function
- Circumscribes/encapsulated
- Necrosis is uncommon
GO LOOK AT A HISTO SLIDE! know what it looks like
What is the etiology of malignant neoplasia? List non-genetic factors
1) Age
2) Lifestyle/environment (tobacco/alcohol)
3) Occupational hazards (chemicals)
4) Radiation (UV!)
5) Infection (HPV - get vaccinated)
6) Inflammation (IBD)
What is the epidemiology of malignant neoplasia?
Almost 1 in 2 American get cancer
1 in 5 will die from it
wow…
Probably related to extended longevity due to healthcare advances
What is the pathobiology of malignant neoplasia?
Think of the two-hit hypothesis w/ genetic causes
1) self-sufficiency in growth signals
2) doesn’t respond to anti-growth signals
3) tissue invasion/metastasis
4) continue to grow w/ checks
5) evade apoptosis
6) Makes its own blood vessels
Discuss TNM classification, stage and relationship to clinical outcome
T: Tumor (Tis -» T4, not so bad -» bad)
N: Regional lymph nodes (N0 -» N2, none -» metastasis in 4+ nodes)
M: Distant metastasis (MX -» M1, can’t be assessed -» yup there is some)
These help calculate which stage of cancer plus survival rate
SEE “Tumor stage and clinical outcome” SLIDE FOR MORE INFO
What is the etiology of malignant neoplasia? List genetic factors
well shit… back to M2M
1) Autosomal dominant (Retinoblastoma, Li-Fraumeni, ya I’m done)
2) Autosomal recessive (xeroderma pigmentosum)
3) Familial (breast, ovarian, pancreatic)
What are 2 mechanisms by which neoplasia develops b/c of disruption of normal homeostasis?
1) Altered cell-autonomous mechanisms
2) Cell-nonautonomous mechanisms
Describe how neoplasia begins through altered cell-autonomous mechanisms
- Activation of oncogenes
- Inactivation of tumor suppressors
Describe how neoplasia begins through cell-nonautonomous mechanisms
- Altered microenvironment — surrounding tissues (stroma, blood vessels, immune cells)
- Altered macroenvironment — circulating cells (e.g. immune cells) and other hormones, GFs
Describe the multi-step pathway of carcinoma development
Injury/infection/other homeostatic disturbance ---->>> Metaplasia/hyperplasia ---->>> Dysplasia/carcinoma-in-situ ---->>> Invasive carcinoma ---->>> Metastatic carcinoma
