Introduction to Detecting Cancer

"If detected in time..."

Early detection is crucial for treating cancer. The sooner cancer is discovered, the greater the chances of successfully treating it. As long ago as the Middle Ages, cancer was thought to be treatable only in its earliest stages. Today, we hear the advice constantly. How can you detect a few cancer cells, newly formed and getting ready to pass on their mutations to the next generation? How many of those cancer cells would have to be present for a physician to detect them?

Cancer detection is part of a larger problem for science—"seeing" or observing the invisible. The chemical interactions that lead to cancer take place at the molecular level, and so they are not directly observable. Scientists have learned to rely on "indirect observation" in cases such as this. For example, do those cancer-causing chemical interactions produce another compound that may be found in the blood or urine by a chemical test? In the case of prostate cancer, such a test is known as a prostate specific antigen (PSA) test.

Mammography being used to detect cancer.

If the mass of cancer cells has grown somewhat larger, might the mass be detectable using X-ray or other imaging technique? X-rays and other kinds of energy give physicians a way to “see” through tissue to detect cancerous growths. This is the basis for the advice that every woman above a certain age should have a mammogram annually. A mammogram is simply an X-ray of the breast.

At later stages of cancer, the cell mass may be large enough to feel or to see. When a physician performs a Pap test, he or she removes a few cells from a woman's cervix and then a pathologist views the cells under a microscope to see if they show any signs of cancer. Breast, testicular and skin self-exams are routine inspections by touch and sight that every person can use to detect possible cancers.

Radioisotope detection.

In this section of Magic Bullets you will perfrom a laboratory activity that simulates the major methods of cancer detection, and, at the discretion of your teacher, and extension activity on self-exams. There is also an activity on cell growth rate. Detecting cancer in larger populations is the subject of the three mathematical activities. There is also a word search activity that will have you trying to find words related to cancer.

The activities in this section include:

Cancer Detectives: A Class Simulation
Cell Growth: Doubling Up
See It Now Part 1: Interpreting a Graph
See It Now Part 2: Interpreting Pie Charts
See It Now Part 3: Making a Bar Graph
Word Search