An Introduction to Cancer

Review of the Cell Cycle Using the flashcards, indicate the part of the cell cycle where each of the following activities occurs. Sister chromatids are moving apart Nuclear membrane begins to fade A new nuclear membrane is forming around the chromosomes The cytoplasm is being divided The chromosomes are not visible The chromosomes condense New organelles form

Nuclear membrane dissolves completely The chromosomes are moving towards the poles of the cell Chromosomes line up along the equator of the cell Spindle fibers pull on the chromosomes Cell is pinched off at the center The cell plate is formed (plant cells) Chromosomes are replicated The longest stage for most cells Centromere splits

Cell Cycle

What if… There is a mutation in the DNA? The cells don’t grow long enough? Cells grow and divide out of control? A step is skipped?

Cancer Cancer is a broad group of diseases that result in uncontrolled cell division. Cancer cells continue to divide despite messages from the nucleus and surrounding cells telling it to stop growing and stop dividing. The cell fails to check off all checkpoints in the G2 phase and is the cell is not killed The uncontrolled growth and divisions results in a growth or a tumor. Tumors can be malignant (cancerous=interferes with functions of surrounding cells) or benign (non-cancerous)

Cell Cycle in Cancer Cells

How Does Cancer Form?

Causes of Cancer Mutations: random changes to the DNA. Cells with mutations may die or may survive and continue to divide. Carcinogens: environmental factors that cause cancer. Tobacco smoke Radiation (x-rays, UV rays) Viruses (HPV) Chemicals in plastics Organic solvents.

Who Gets Cancer? If a group of people is exposed to a carcinogen not every one of them will get cancer. It is hard to predict who will get cancer. Some cancers have a genetic link (breast, colon, ovarian and uterine). People who have this link are more at risk to developing cancer Smokers: Lung cancer is one of the most common types of cancer in Canadians over 40. Smoking is the cause in 9 out of 10 of these cases.

How to Prevent Cancer Reduce your exposure to carcinogens Diet—super foods that may reduce chances of cancer (Page 51) Cancer screening=checking for cancer even if there is no symptoms. Some of these can be done at home (self check for breast cancer) while others must be done at a doctors office (Pap test for cervical cancer, blood tests and PSA for testicular cancer) or at a medical lab (blood tests) Early detection is important to ensure that the cancer can be treated.

How Do I Know if I have Cancer? In some cases the tumor is visible as a swelling or causes discomfort Use of imaging technologies (x-ray, ultrasound, CT scan, MRI, endoscopy) If there are abnormalities in the medical tests/images, the cancer cells are examined under the microscope, cancer cells normally have irregular shapes **Note: If you suspect cancer, you should immediately talk to your doctor as early detection can save your life!

Treatments for Cancer Surgery: removal of the cancerous tissue. This is sometimes the preferred way especially if the cancer is easy to get to and well defined. Draw back is the recovery time and possibility of infection Chemotherapy: drugs are used to slow down the division and spread of the cancer cells. Drugs are injected or taken orally. Side effects may include: hair loss, nausea, fatigue Radiation: cancer cells are damaged by radiation because they divide so fast. Radiation is directed at the tumor by focusing the radiation beam or implanting a radioactive source in the tumor.

Biophotonics: cutting edge technology. Beams of light detect and treat cancer. Biophotonics are very sensitive and can detect early signs of cancer. Fewer side effects than radiation because it can more accurately target cancerous tissue.