Cancer Biology & Epidemiology

# Biological Causes of Cancer

* Avoiding immune destruction
* Evading growth suppressors
* Enabling replicative immortality
* Tumor-promoting inflammation
* Activating invasion and metastasis
* Genomic instability
* Inducing angiogenesis
* Resisting cell death
* Deregulating cellular energetics
* Sustaining proliferative signaling

# Nomenclature

* Benign: -oma
* Malignant epithelial tissue: -carcinoma
* Malignant connective tissue: -sarcoma
* Fatty tissue: lip-
* Gland tissue: adeno-
* Fibrous tissue: fibro-
* Bone: osteo-
* Cartilage: chondro-
* Blood vessel: hemangio-
* Smooth muscle: leiomyo-
* Striated muscle: rhabdomyo-

# Special Nomenclature

* Hodgkin’s lymphoma
* Wilms’ tumor
* Ewing sarcoma
* Melanoma → malignant
* Heptamoa → carcinoma

# Molecular Basis of Cancer

* 2 genes, 1 that promotes, 1 that represses; when either one is defective, they both cause uncontrolled cell growth
* Signaling genes:
* Proto-oncogenes (RAS, MYC); normal cell proliferation
* Oncogenes (oncoproteins); mutated proto-oncogenes, uncontrolled cell growth
* DNA repair genes:
* BRCA1: chromosome 17
* BRCA2: chromosome 13
* Can be spontaneous or heritable
* Apoptosis genes:
* BAX
* BCL-2
* **These are defective cells that favor cell survival when it should be programmed cell death**

# Tumor Suppressor Genes

> Regulate cell cycle, inhibit cell proliferation, stop cell division, and prevent mutations (normally)

* Governors: prevent bad things from happening, but the “brake” on
* Guardians: like the police, tag the bad things, and monitor; damage control
* P53, APC

# Angiogenesis

> Growth of new vessels

* Vascular endothelial growth factor (VEGF)
* Cancer can create new routes of energy/life for itself so it creates more blood vessels to keep it alive
* Avastin stops the growth of blood vessels

# %%Warburg Effect%%

* Use of glycolysis under normal oxygen conditions, aerobic glycolysis and oxidative phosphorylation
* For every 1 glucose = 1 ATP; completely shuns the mitochondria
* Allows rapid cell growth
* Activated by oncogenes and mutant tumor suppressors

# ==Reverse Warburg Effect==

* **@@LACTATE = LAZY@@**
* Doesn’t shun the mitochondria
* Tumor cells can demand for other cells to make extra @@lactate@@ to keep them fed, hence, reprograms the other cell’s metabolism
* Makes other cells do the work for the tumor

# The 1-5 Year Survival:

* A patient comes in and the cancer is removed surgically
* After surgery, day 0 begins
* If the cancer came back within 1 year, the chance of survival from the specific cancer is lowered
* If the cancer did NOT come back, there is a higher chance of survival to 5 years

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# Staging

> How far has the cancer spread?

* Stage I: No metastasis
* Stage II: Local invasion
* Stage III: Spread to regional structures
* Stage IV: Distant metastasis

**%%★ Universal system%%**

* T: Tumor spread (T-T3)
* N: Node involvement (N-N2)
* Metastasis: Metastases (M-M2)

## Staging Colon Cancer

* Duke’s A: stage I, no metastasis
* 5 yr survival >90%
* Duke’s B: stage II, local invasion
* 5 yr survival 55% to 85%
* Duke’s C: stage III, spread to regional structures
* 5 yr survival 20% to 55%
* Duke’s D: stage IV, distant metastasis
* 5 yr survival