Cell Division Going Wrong: Cancer
 When cells divide, their DNA is almost always duplicated errorfree.
 The genetic information in the daughter cells is identical to the
parent cell.
 Sometimes random changes occur in the cell’s DNA. These
changes are called mutations.
 Mutations may result in the death of the cell or allow it to
survive and continue to grow and divide.
 Cancerous cells are formed when there is a mutation in
the portion of the DNA controlling the cell cycle.
 This change prevents the cell from staying in interphase for the
normal period of time.
 When the normal checkpoints fail, the cell and its daughter cells
will divide uncontrollably.
 When cells grow and divide out of control, they cause a group
of diseases called cancer.
Telomerase
The telomeres (ends of the chromosomes) in most cells shorten after
each division, eventually causing cell death
Shortening telomeres also cause aging
Cancer cells have unique features that make them "immortal"
They have an enzyme called telomerase, which extends the cancer
cell's life span.
This is a major reason that cancer cells can accumulate over time
creating tumors.
Causes of Cancer
 Carcinogens
o Tobacco smoke
o Radiation (X-rays, UV rays)
o Viruses such as HPV and hepatitis B
o Certain chemicals in plastics
o Many organic solvents
o Hereditary links (breast, colon)
- it is very difficult to predict who will develop cancer
Cancer Screening





Breast / testicular self-examinations
Regular Pap tests
PSA tests
Blood tests
ABCD for moles
Reducing Cancer Risks – Lifestyle Choices
Diagnosing Cancer




Discomfort
Swelling
Tiredness
Loss of weight






Endoscopy – colon
X-ray – lung / breast
Ultrasound –heart / liver
CT scanning MRI
Biopsies
Cancer Treatments




Surgery
Chemotherapy
Radiation (ionizing)
Biophotonics – beams of light to detect / treat