What Science Knows about Cancer

Arm yourself with information. In this course taught by a frontline cancer researcher, you discover how cancer is caused, how it works, and what science is doing to stop it.


Few global challenges touch humanity with as much immediacy or ubiquity as cancer. The good news is that the landscape of cancer treatment and prevention is a vastly different place than it was even a decade ago. What Science Knows about Cancer reports from the front lines of the war on cancer with a clear and scientifically precise-yet thoroughly accessible-guide to how the disease develops, thrives, and can potentially be conquered. Taught by David Sadava, a laboratory researcher at the City of Hope Medical Center and an award-winning professor of biology at The Claremont Colleges, this highly visual 24-lecture course leaves no stone unturned in explaining the amazing ways cancer works to subvert the body's normal functioning, and how therapies can reverse these insidious processes. Disclaimer: These lectures are not designed for use as medical references to diagnose, treat, or prevent medical illnesses or trauma. Neither The Great Courses nor Professor Sadava is responsible for your use of this educational material or its consequences. If you have questions about the diagnosis, treatment, or prevention of a medical condition or illness, consult a qualified physician.


David Sadava
David Sadava

The DNA double helix, discovered in 1953, is one of the great icons of science in our society, rivaling the atom in its pervasiveness in our culture.


City of Hope Medical Center, Claremont Colleges

Dr. David Sadava is Adjunct Professor of Cancer Cell Biology at the City of Hope Medical Center in Duarte, CA, and the Pritzker Family Foundation Professor of Biology, Emeritus, at The Claremont Colleges. Professor Sadava graduated from Carleton University as the science medalist with a B.S. with first-class honors in biology and chemistry. A Woodrow Wilson Fellow, he earned a Ph.D. in Biology from the University of California, San Diego. Following postdoctoral research at the Scripps Institution of Oceanography, he joined the faculty at Claremont, where he twice won the Huntoon Award for Superior Teaching and received numerous other faculty honors. He has been a visiting professor at the University of Colorado and at the California Institute of Technology. Professor Sadava has held numerous research grants and written more than 55 peer-reviewed scientific research papers, many with his undergraduate students as coauthors. His research concerns resistance to chemotherapy in human lung cancer, with a view to developing new, plant-based medicines to treat this disease. He is the author or coauthor of five books, including the recently published 10th edition of a leading biology textbook, Life: The Science of Biology, as well as a new biology textbook, Principles of Life.

By This Professor

What Science Knows about Cancer


Cancer Is an Ongoing Challenge

01: Cancer Is an Ongoing Challenge

Kick off the course with an overview of what you'll learn and the history of cancer. Discover what has transpired in the war on cancer, from the earliest theories and treatments to medicine's relatively recent transition from a focus on dividing cells to targeted therapy based on molecular biology.

31 min
Cancer Is a Major Burden to Society

02: Cancer Is a Major Burden to Society

As you investigate why cancer is a growing problem in the United States and across the globe, explore the burden cancer places on society as a whole-both to people and the economy-and look at some of the most common forms of the disease. See why, surprisingly, cancer doesn't rank on the Global Burden of Disease Study.

30 min
Discovering Causes of Cancer in Populations

03: Discovering Causes of Cancer in Populations

What do population studies tell us about the causes of cancer? Define the science of epidemiology and learn how it can be used to study cancer in both populations and individuals. Differentiate between case-control and cohort studies, and the categories of risk factors for cancer.

30 min
Some Causes of Cancer in Populations

04: Some Causes of Cancer in Populations

Continue exploring epidemiology by delving into environmental causes of cancer that have emerged from studies, including tobacco, diet, a woman's reproductive status, medications, pesticides, radiation, and even your personality. How does giving birth later in life make you more vulnerable to breast cancer? Is the average person's exposure to pesticides really dangerous? Find out here.

31 min
DNA Is the Key to Understanding Cancer

05: DNA Is the Key to Understanding Cancer

Take the first steps in understanding the multistage model of cancer by learning how various agents initiate cancer at the genetic level. Explore the fundamentals of DNA as genetic material, the process by which DNA is expressed and duplicated, and the ways this process of duplication can go awry, causing cell mutations to accumulate.

30 min
How Does DNA Change to Initiate Cancer?

06: How Does DNA Change to Initiate Cancer?

Two types of carcinogens mutate DNA: chemicals and radiation. Build on what you've learned about DNA by looking specifically at how these carcinogens produce cancer at the cellular level. Then, examine carcinogens that don't damage DNA and how epigenetic changes in DNA can result in cancer.

31 min
How Do We Know If Something Causes Cancer?

07: How Do We Know If Something Causes Cancer?

Does hair dye cause cancer? What about saccharin? Familiarize yourself with the types of experiments scientists conduct to determine if something causes cancer, and consider whether a range of natural and manmade substances with carcinogenic properties have the potential to cause cancer in humans. Conclude this lecture by looking closely at the concept of risk analysis.

32 min
How Do Normal Cells Function?

08: How Do Normal Cells Function?

Focus on cells as the basic structures of living things through an exploration of their internal composition, particularly the nucleus where the genome is retained. See how this discovery was proven in the cloning of Dolly the sheep and consider how this is relevant to cancer treatment.

31 min
What Is Different about Cancer Cells?

09: What Is Different about Cancer Cells?

How do tumors start? Find out how cells divide without normal controls in place and the nine unusual properties shared by many cancerous cells-including the ability to recruit a blood supply. Then learn about the process of apoptosis, or programmed cell death, and the molecules being developed to block telomerase, a protein that lets cancer cells escape dying.

30 min
How Do Tumors Grow?

10: How Do Tumors Grow?

What is the difference between benign and malignant tumors? What signs of cancer do people typically experience? Turn to tumor development and growth with a discussion of the methods doctors use to diagnose, stage, and grade tumors-all of which inform how aggressive treatment should be-and an introduction to the distressing processes of metastasis and angiogenesis.

30 min
How Tumors Spread and Thrive

11: How Tumors Spread and Thrive

The body does everything it can to reject a tumor, but sometimes the immune system is not only too overburdened to succeed, it's unable to even recognize that tumors exist. Find out why tumors can go undetected as you continue your investigation of metastasis and angiogenesis, and how these phenomena contribute to the growth and spread of tumors.

31 min
What Are Tumor Viruses?

12: What Are Tumor Viruses?

Most of us will be infected with-and recover from-Epstein-Barr virus at some point in our lives. In some people, this infection contributes to the development of cancer. Understand what viruses are, how tumor viruses can be identified, and the way viruses such as Epstein-Barr, hepatitis B, and papilloma cause cancer if other conditions are present.

32 min
How Do Tumor Viruses Cause Cancer?

13: How Do Tumor Viruses Cause Cancer?

Learn about molecular biology and how gene expression is controlled before turning to an investigation of the way tumor viruses use these gene control mechanisms to initiate cell division, and, ultimately, cancer. Wrap up by looking at how cancer develops in 90% of cases-from normal cells that aren't infected by viruses.

28 min
How Do Cancer-Causing Genes Work?

14: How Do Cancer-Causing Genes Work?

In almost all cancer, genes that stimulate cell division called oncogenes are mutated. But can one such mutation cause cancer on its own? Examine an experiment that answers this question, then look closely at proto-oncogenes and oncogenes to discover how they function and what they do in the cell to turn on cancers, including neuroblastoma tumors in children.

30 min
Can Cancer Be Inherited?

15: Can Cancer Be Inherited?

Why do cancers sometimes run in families? Explore the "two-hit" hypothesis for how cancers are inherited along with the criteria for defining cancer as hereditary with a discussion of several forms-including retinoblastoma, colon cancer, and breast cancer-that are known to be passed on this way. Explore inherited susceptibilities to cancer that make some people more prone to developing this diseas...

30 min
How Do Normal Genes Suppress Tumors?

16: How Do Normal Genes Suppress Tumors?

Now that you understand oncogenes, focus on tumor suppressor genes for a more complete view of cancer. Start by learning how the BRCA1 gene mutation in inherited breast cancer was discovered-and its implications-before turning to strategies for identifying and isolating suppressor genes to be used in therapy. Explore the genes' functions, from repairing DNA damage to acting as brakes in the cell d...

32 min
How Do Genetic Changes Result in Cancer?

17: How Do Genetic Changes Result in Cancer?

All tumors are not created equal. Trace how cancer develops as a series of molecular changes, then learn how the worldwide Cancer Genome Project is working toward individualized therapies. Conclude by looking at genetic testing and considering its ethical and legal ramifications.

33 min
Treating Cancer with Surgery

18: Treating Cancer with Surgery

From research to clinical trials to approval, cancer therapies face a long road before they become viable treatment options. As you turn to the science behind surgical cancer therapy, explore this developmental process. Using breast cancer as an example, learn the scientific principles of surgical therapy and how it has evolved. Weigh the pros and cons of using surgery to diagnose cancer, remove l...

31 min
Treating Cancer with Radiation

19: Treating Cancer with Radiation

Continue your investigation of ways to treat cancer by learning how radiation treatments, including proton therapy, brachytherapy, and radiosurgery, are often used to kill cancer cells. Next, explore the use of stem cell transplantation to restore the bone marrow of patients who've experienced high doses of radiation or chemotherapy.

32 min
Treating Cancer with Drugs

20: Treating Cancer with Drugs

Turn to the last of the three methods of treatment with this lecture that traces the origins of chemotherapy to mustard gas attacks in World War II. Learn about the path taken by a drug on its way to a tumor, the combinations of chemotherapy used by oncologists, and how drugs are often derived from plants and other natural sources.

31 min
How Do Drugs Attack Cancer?

21: How Do Drugs Attack Cancer?

Some cancer drugs go to work on DNA while others target processes inside the cell. Get an introduction to both categories and learn the science behind how widely used drugs such as methotrexate, tamoxifen, and cisplatin operate. Consider the side effects patients commonly experience when undergoing chemotherapy and the reasons cells become resistant to treatment. Then, using kidney cancer as an ex...

34 min
Frontiers of Cancer Treatment

22: Frontiers of Cancer Treatment

Explore avenues of treatment at the frontiers of science, starting with how a patient's own immune system can be harnessed in cancer therapy. Take an in-depth look at antibodies and gene therapy as options for treatment and consider the amazing potential of viruses that target tumors only and leave normal cells undamaged.

31 min
Can Screening for Cancer Be Useful?

23: Can Screening for Cancer Be Useful?

Why are monthly breast self-examinations no longer recommended in some countries? Do PSA screenings for prostate cancer have any impact on survival rates for men with the disease? Examine the science of screening and the success rates of current screening methods for cancers of the breast, cervix, colon, and prostate, and consider whether getting screened is worthwhile given the risks and costs as...

32 min
Can Cancer Be Prevented?

24: Can Cancer Be Prevented?

Conclude the course with a discussion of prevention, from carcinogens to avoid to substances that studies indicate could offer chemoprevention in a wide variety of cancers. Learn why identifying carcinogens and preventive agents is so challenging for researchers, and look toward the promising future of treatment and prevention.

35 min