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Quick review…

• What is the cell cycle?

• Hmmm….what regulates/controls the cell cycle and tells each cell when to divide?

What is cancer?

• Cancer is a disease of cells, the basic building blocks of our bodies.

• The life and behavior of each cell in our body is controlled by genetic instructions. That is the job of our DNA!

• Those instructions tell our cells when and how to grow, reproduce and die.

(Think “normal” cell cycle)

What is cancer?

• Sometimes a cell might start behaving and reproducing in an uncontrolled way.

When that happens, we call it cancer.

**Research** Why does this happen? Are there things that we do to increase our risk? How can we decrease our risk? Can we prevent cancer from forming in our bodies? If we get cancer, how can we get rid of it?...so many questions!!

How does a cell become cancerous?

All cancers start from a single cell that undergoes many changes.

Some of those changes are permanent alterations to the DNA called mutations.

Luckily, our bodies have a host of defensive strategies for making sure damaged or mutated cells never get the chance to reproduce*

(**this is why it can take so long for cancer to develop in the body.)

• Over our lifetimes, thousands and thousands of damaged cells get disposed of before they can cause any harm.

• But if a cell does manage to get past our defenses and start multiplying without control, it can form a mass of abnormal cells called a tumor

• Not all tumors are dangerous.

• Those that arise and then go quiet are called benign.

• Malignant or cancerous tumors can spread into surrounding tissues, damaging nearby cells or organs.

Types of Cancer

• The four major types of cancer are carcinoma, sarcoma, lymphoma, and leukemia.

• Carcinomas -- the most commonly diagnosed cancers -- originate in the skin, lungs, breasts, pancreas, and other organs and glands.

• Lymphomas are cancers of lymphocytes.

• Leukemia is cancer of the blood. It does not usually form solid tumors.

• Sarcomas arise in bone, muscle, fat, or cartilage and are relatively uncommon.

What Causes or Protects Against

Cancer?• Cancer is not a single disease, and

no single factor is likely to be the cause.

• Many things contribute to cancer development, but we now know that a significant number of cancers are caused by lifestyle factors like smoking, poor diet, and excess body fat.

• Many substances in plant foods can help our natural defenses prevent damage or even repair our cells.

• Daily physical activity also seems to help prevent some major cancers from developing and even from recurring among survivors.

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• The choices listed on the right can help protect your cells against damage and lower your risk for cancers. The choices listed on the left side can increase your cancer risk.