Is Cancer Infectious?

Print Friendly, PDF & Email
About This Module

Topics: Human health, epidemiology, virus, cancer, infectious agents, immunizations

Grade levels: 9-12

Overview

Students take on the roles of doctors treating patients with virus-linked cancers. They review cases, investigate possible links to different types of cancer, and find out about treatments, prognoses, and immunizations against the viruses linked to cancer.  Students investigate the question: Is cancer infectious?

Learning Objectives

To better understand the link between viruses and cancers and the body’s immune responses, the student should be able to:

  • Describe how cells become cancerous.
  • Explain the difference between a normal cells and a cancer cell.
  • Explain how pathogens can cause cancer.
  • List factors other than viruses that cause cancer.
  • Compare and contrast the symptoms, treatment and prognoses of different virus-linked cancers.
  • Describe the immune system’s role in fighting infectious disease and cancer.
Standards

Next Generation Science Standards

Standards Aligned to PBL Modules

 

Possible Answers to Scenario Guided Questions

HCV and liver cancer

Part I:

  1. How do cells become cancerous? What is the difference between a normal cell and a cancer cell? What is the difference between a tumor and cancer?

Cells become cancerous when mutations in the cell’s DNA cause uncontrolled cell division. Cell control over genes that signal apoptosis are often altered, absent, or malfunctioning in about half of cancer patients tested. Cancer cells divide and pass along defective gene coding. Masses of cancer cells grow, form tumors, and interfere with normal body functioning.

In cancer cells, normal cell division does not stop. In normal cells, division is controlled by a number of “signals” and cell division stops.

A tumor is a growth caused by cells dividing abnormally, but it does not have to be cancer. A tumor may be benign—they do not spread to other body tissues. Malignant growths are made up of abnormal cells which divide rapidly and have destructive physical and metabolic effects on the tissues around them. Malignant growths can travel to other parts of the body (metastasis), but do not always travel from the originally affected tissue.

  1. How can infectious agents cause cancer?

Some viruses attack the immune system and weaken the body’s disease-fighting capabilities. Without the protection of immune responses, the body is more vulnerable to attack by opportunistic infections and certain viruses are associated with the development of cancers. Some viruses cause chronic infections of certain body parts which can lead to cancer. For example, chronic infection with the hepatitis C virus can lead to chronic liver disease and liver cancer.

  1. What other factors besides viruses can cause cancer? Name other factors and how they cause cancers.

There is a link between genetic history and cancer. You can inherit a predisposition to developing a certain type of cancer, but that doesn’t mean you will get cancer. There are a lot of other factors that influence whether or not someone will develop cancer in their lifetime.

Lifestyle choices can make you more vulnerable to developing cancer. Tobacco products contain carcinogens (anything that causes cancer) and using tobacco products increases the risk of cancer of the lungs, mouth, larynx, throat, esophagus, kidney, cervix, liver, bladder, pancreas, stomach, and colon, and is linked to an increased risk of myeloid leukemia.

All tobacco products, including smokeless tobacco products increase the risk of cancers. There is no safe way to use tobacco products.

Any exposure to a carcinogen can cause cancer. Besides viruses and tobacco, exposures to toxic environmental chemicals, toxic chemicals in the workplace, such as asbestos or benzene, radiation, prolonged ultraviolet rays from the sun, alcoholism, and chronic inflammation are linked to increased risk for a variety of cancers.

  1. How does cancer spread from one part of the body to other parts?

All cancer cells have abnormal growth and cell division. Cellular cytoplasm becomes disorganized. New proteins trigger formation of increased small blood vessels which feed the growing tumor cells. Cells lose adhesion capability; they don’t stay fixed to tissues and can migrate to other body tissues.

Cancer cells often do not form normal cytoskeletal networks or plasma membranes. Some malignant cancer cells break loose from tissues and enter lymph or blood vessels. They can then travel through the body lodging in other areas. They continue to multiply in the new locations. This process of migration is called metastasis.

  1. Usandra’s cancer is fairly rare. How did she develop this cancer?

Usandra does not have many risk factors which may have caused her hepatitis C-associated liver cancer. She has never received a blood transfusion (blood screening for hepatitis became available in 1992), she is not the recipient of an organ transplant, she has never been on hemodialysis, she has never gotten a tattoo, she is not a health care worker who may have been infected by a contaminated needlestick, she is not HIV-positive, and she was not born to an hepatitis C mother.

However, Usandra did use injected drugs years ago. This is probably where she came into contact with the hepatitis C virus and was infected. Injected drugs are the most common way hepatitis C virus is spread in the U.S.

  1. What are Usandra’s treatment options?

Usandra’s treatment choices are going to depend on many factors, including the extent of her cancer and her overall health status. Some options are:

  • surgery—cutting out the cancerous part of the liver
  • radiofrequency ablation—using high-energy radio waves to destroy small tumors
  • ethanol ablation—injecting alcohol into the tumors to kill cancer cells
  • microwave thermotherapy—using microwaves transmitted through a probe to kill cancer tissues
  • cryotherapy—freezing tumors by injecting tumors with very cold gasses
  • embolization—blocking or reducing the number of blood vessels to cancer cells
  • radiation—using radiation to shrink liver rumors
  • chemotherapy—using drugs to kill cancer cells.

Each one of these options has side effects that must be considered before an oncologist decides on the best method of treatment. Each option has different approaches or strategies that may work better for one type of liver cancer than another. A combination of treatments may be necessary in order to improve Usandra’s life span and quality of life while she battles liver cancer.

  1. What is Usandra’s prognosis? What specific issues are of concern in this type of cancer that may affect Usandra’s outcome? Does this type of cancer usually spread to other parts of the body?

Usandra’s prognosis depends on many issues of her particular case of liver cancer. The specific type, the stage of cancer, and her overall health will affect her prognosis. Some types of liver cancers are easier to treat than others.

Liver cancer does not respond that well to chemotherapy, so Usandra’s treatment most likely will not rely on just that option.

In nearly all cases, liver cancer is a metastasized cancer—the cancer originally occurred somewhere else and has spread to the liver. Once a cancer has spread to the liver, there is no cure, but treatments can increase life expectancy and relieve symptoms.

The 5-year survival rate for people with localized liver cancer is about 31%.

The 5-year survival rate for people with regional liver cancer (the cancer has spread to nearby lymph nodes) is about 11%

The 5-year survival rate for people with distant liver cancer (the cancer has spread to distant organs is about 3%.

Patients with small tumors with no other serious health problems have a 5 year survival rate of 50% if the cancer can be removed.

Source for survival rates: American Cancer Society

  1. What part does the body’s immune system play in fighting off infectious disease and cancer?

The body’s immune system recognizes foreign materials, such as pathogens, and can fight off infections. In the case of cancer, the immune system must recognize a cell that is different and harmful, yet one of the body’s own cells. Immune system cells can successfully destroy some cancer cells, but may not be successful at destroying all the cancer cells that are in a tumor.

Immunotherapy, using the body’s immune system to more effectively kill cancer cells, has been used to treat melanomas (skin cancer), prostate cancer, Hodgkin lymphoma, and certain types of brain tumors.

  1. Is cancer an infectious disease?

We usually think of an infectious disease as being one that you can “catch” from another person or one that you get from being bitten by a vector (disease-carrying animal). You cannot “catch” cancer in this way. But, certain viruses can make us susceptible to developing different types of cancer, and in this way, cancer could be considered an infectious disease.

You can get a vaccine to eliminate cancer risks associated with some viruses which prevents the infection by the virus. But, not all viruses associated with cancer have vaccines that prevent viral infection. For those viruses without vaccines, you can avoid behaviors that increase the risk of infection and possible development of cancer.

Part II:

Answers will vary.

Note to Teacher:  Only Part I questions 5, 6, and 7 change considerably for the other virus-associated cancers in this PBL. Use the general cancer question answers for other virus-associated cancer scenarios and see below for answers to specific cases.

Answers to questions 5, 6, and 7 for other virus-associated cancers

HBV and liver cancer  

  1. This cancer is fairly rare in someone this young. How did Aaron develop this cancer?

Aaron does not have many risk factors which may have caused his Hepatitis B-associated liver cancer. He has never received a blood transfusion (blood screening for hepatitis became available in 1992), he is not the recipient of an organ transplant, he has never been on hemodialysis, he is not a health care worker who may have been infected by a contaminated needlestick, he has not used injected drugs, he is not HIV-positive, and he was not born to an hepatitis B mother.

However, Aaron does have many tattoos which he received over a period of a few years at different tattoo businesses. This is probably where he came into contact with the hepatitis B virus and was infected.

  1. What are Aaron’s treatment options? As his oncologist, what are your recommendations?

Aaron’s treatment choices are going to depend on many factors, including the extent of his cancer and his overall health status. Some options are:

  • surgery—cutting out the cancerous part of the liver
  • radiofrequency ablation—using high-energy radio waves to destroy small tumors
  • ethanol ablation—injecting alcohol into the tumors to kill cancer cells
  • microwave thermotherapy—using microwaves transmitted through a probe to kill cancer tissues
  • cryotherapy—freezing tumors by injecting tumors with very cold gasses
  • embolization—blocking or reducing the number of blood vessels to cancer cells
  • radiation—using radiation to shrink liver rumors
  • chemotherapy—using drugs to kill cancer cells.

Each one of these options has side effects that must be considered before an oncologist decides on the best method of treatment. Each option has different approaches or strategies that may work better for one type of liver cancer than another. A combination of treatments may be necessary in order to improve Aaron’s life span and quality of life while he battles liver cancer.

  1. What is Aaron’s prognosis? What specific issues are of concern in this type of cancer that may affect Aaron’s outcome? Does this type of cancer usually spread to other parts of the body?

Aaron’s prognosis depends on many issues of his particular case of liver cancer. The specific type, the stage of cancer, and his overall health will affect his prognosis. Some types of liver cancers are easier to treat than others.

Liver cancer does not respond that well to chemotherapy, so Aaron’s treatment most likely will not rely on just that option.

In nearly all cases, liver cancer is a metastasized cancer—the cancer originally occurred somewhere else and has spread to the liver. Once a cancer has spread to the liver, there is no cure, but treatments can increase life expectancy and relieve symptoms.

The 5-year survival rate for people with localized liver cancer is about 31%.

The 5-year survival rate for people with regional liver cancer (the cancer has spread to nearby lymph nodes) is about 11%

The 5-year survival rate for people with distant liver cancer (the cancer has spread to distant organs is about 3%.

Patients with small tumors with no other serious health problems have a 5 year survival rate of 50% if the cancer can be removed.

Source for survival rates: American Cancer Society

EBV and Burkitt lymphoma

  1. This cancer is fairly rare in someone this young. How did Samira develop this cancer?

Samira is from Ethiopia. Certain parts of Africa have recently seen an increase in the incidence of Burkitt lymphoma.  In Africa, Burkitt lymphoma is endemic, meaning that the cancer is regularly found there, and is almost always associated with the Epstein-Barr virus. Samira probably came into contact with EBV in Ethiopia and was infected.

  1. What are Samira’s treatment options? As her oncologist, what are your recommendations?

Samira doesn’t have a lot of options. It is critical that treatment begin as soon as possible as Burkitt lymphoma is a fast growing tumor.

Treatment for Burkitt lymphoma is usually chemotherapy involving several different drugs given on consecutive days. IV treatments usually take several days.

Side effects of chemotherapy should be carefully assessed and treated, if needed.

  1. What is Samira’s prognosis? What specific issues are of concern in this type of cancer that may affect Samira’s outcome? Does this type of cancer usually spread to other parts of the body?

Burkitt lymphoma is the fastest growing human tumor and is fatal if left untreated.  But, with treatment Samira’s prognosis is good. More than half of the people with Burkitt lymphoma are cured with intensive chemotherapy and prompt treatment can yield long-term survival rates of 70-80% in adults. Issues of concern are the spread of this type of cancer to the bone marrow or spinal fluid. Spread of the cancer negatively affects the prognosis. The rate also decreases if the cancer returns after a remission.

Patients with Burkitt lymphoma also have a high risk of tumor lysis syndrome. Tumor lysis syndrome results as a complication of chemotherapy. Large numbers of cancer cells are killed, but release their contents into the bloodstream. Identifying patients who may be at increased risk of the syndrome and taking preventative measures before and during chemotherapy can lessen adverse effects. Supportive care throughout treatment improves the patient’s condition and recovery.

HPV and oropharyngeal cancer

  1. This cancer is fairly rare in someone this young. How did Casey develop this cancer?

Casey doesn’t have many of the risk factors that are associated with this type of cancer other than his infection with the Human Papilloma Virus. HPV was found in the tissues biopsies that were taken from Casey’s tumor.

Casey probably developed this HPV-associated cancer from his infection. HPV is a very common sexually transmitted disease and can be transmitted even when an infected person has no symptoms of having a disease. You may develop symptoms years after being infected, making it difficult to know exactly when you were infected.

  1. What are Casey’s treatment options? As his oncologist, what are your recommendations?

There is no cure for HPV. (However, there is a vaccine that could have prevented his HPV infection. Casey did not get the vaccine.) While Casey could not have cured his HPV infection, if he found out about the infection earlier, he may have been able to treat the cancer before it progressed to a more advanced stage.

There is a high rate of success for treating oropharyngeal cancer with surgery and/or radiation therapy. Chemotherapy after surgery is also an option to treat any cancer that may be left after surgery.

While curing the cancer is always the most important goal of treatment, it is also important to try to maintain the function of the tissues surrounding the treated area. Ideally, the function of nerves, organs, and tissues would have as little as damage as possible due to surgical, radiation, or chemotherapy treatments.

 What is Casey’s prognosis? What specific issues are of concern in this type of cancer that may affect Casey’s outcome? Does this type of cancer usually spread to other parts of the body?

Casey’s prognosis is very good. Oropharyngeal cancer can be cured with effective treatment. Issues of concern include maintaining the patient’s ability to speak and swallow normally. The cancer can recur, but is less likely to recur if the patient does not smoke or drink alcohol.

Patients with oropharyngeal cancer have an increased risk of having cancer in another area of the head or neck.

HIV and Kaposi sarcoma (KS)

  1. How did Michael develop this cancer?

Michael has few risk factors for developing cancer, except that he is HIV positive. Michael probably became infected with HIV when he used drugs years ago. He has no other risk factor for HIV infection.

Michael’s HIV infection attacks disease-fighting white blood cells and weakens the body’s immune system. In spite of his HAART (highly active antiretroviral therapy), he has developed KS. In addition to Kaposi’s sarcoma, other types of cancer, such as Hodgkin disease, cancers of the mouth and throat, liver cancer, and some types of skin cancers, are also linked to HIV infection.

  1. What are Michael’s treatment options? As his oncologist, what are your recommendations?

Michael could start on additional antiretroviral therapy to slow down the progression of KS. Radiation therapy, surgery for removing the lesions, and chemotherapy are options for KS treatment.

Immunotherapy is also a promising option used to treat some cancers. In immunotherapy, drugs that boost or restore the body’s natural defenses against cancer are given to help the patient fight the cancer.

  1. What is Michael’s prognosis? What specific issues are of concern in this type of cancer that may affect Michael’s outcome? Does this type of cancer usually spread to other parts of the body?

More effective treatments for both HIV/AIDS and KS are improving survival rates for these infections. The 5 year survival rate for HIV positive people with Kaposi sarcoma was less than 10% when the HIV/AIDS epidemic first began. Now, the 5 year survival rate is about 72%. (National Cancer Institute)

KS can spread to other organs and become life-threatening. KS has been known to spread to the lungs, liver, esophagus, skin, mouths, nose, or throat.

Sample Rubric

Information about constructing and implementing rubrics for problem-based learning strategies can be found in Developing Rubrics in the Teacher Professional Development section.

 

Additional Resources

Additional resources about virus-linked cancer can be found:

in the Internet Resources in any of the “Is Cancer Infectious?” scenarios at
http://www.pandemsim.com/pdc/is-cancer-infectious-ebv/

in the Internet Resources –Viruses and Cancer at
http://www.pandemsim.com/pdc/internet-resources-viruses-and-cancer/