Cancer patients, after coming to grips with our diagnosis and forming a battle plan, often wonder “how did I get cancer” or “what caused my cancer?” On the global war against cancer, understanding the causes of cancer is an important component of cancer prevention. We cannot afford any ignorance in the areas understanding the causes of cancer, treating cancer, and preventing cancer. The National Cancer Institute estimates that, in 2014, 1,665,540 people will be diagnosed with cancer in the United States, and 585,720 people will die of cancer!
We are learning more about what causes cancer. More is known about the cause of some forms of cancer than others. For example, everyone now knows that cigarette smoking (and second-hand exposure to smoke) causes lung cancer. We are past mere associations and can say definitively that there is cause and effect between cigarette smoking and lung cancer.
Similarly, the virus causing cervical cancer has been identified and should be tested for regularly in woman. There are associations between many cancers and inflammatory conditions: lung cancer and cigarette smoke; liver cancer and hepatitis; Malt lymphoma and stomach cancer and Helicobacter pylori; colon and rectal cancer and inflammatory bowel disease; cervical cancer and Papillomavirus; and mesothelioma and asbestos are some examples. Saint Louis University Medical Center researchers recently reported that there is a much higher risk of pancreatic cancer in patients with acute pancreatitis than commonly believed.
Case Western Reserve University researchers recently discovered how byproducts in the form of small fatty acids from two bacteria prevalent in gum disease incite the growth of deadly Kaposi’s sarcoma-related lesions and tumors in the mouth.
With respect to blood cancer, the answer often is less clear. It is difficult to say what caused lymphoma in any individual person. There is evidence suggesting associations between some lymphomas and environmental and occupational exposures to some chemicals, including: benzene; petrochemicals and combustion by-products (such as polycyclic aromatic hydrocarbons and soot); some pesticides, fungicides, insecticides, and herbicides (such as Agent Orange used in Vietnam); hair dyes, polychlorinated biphenyls, and solvents (such as styrene, trichloroethylene, and tetrachloroethylene). The associations are stronger in some instances than in others.
Benzene appears to be a significant culprit when it comes to blood cancers. According to the Centers for Disease Control and Prevention:
The major effect of benzene from long-term exposure is on the blood. (Long-term exposure means exposure of a year or more.) Benzene causes harmful effects on the bone marrow and can cause a decrease in red blood cells, leading to anemia. It can also cause excessive bleeding and can affect the immune system, increasing the chance for infection.
Some women who breathed high levels of benzene for many months had irregular menstrual periods and a decrease in the size of their ovaries. It is not known whether benzene exposure affects the developing fetus in pregnant women or fertility in men.
Animal studies have shown low birth weights, delayed bone formation, and bone marrow damage when pregnant animals breathed benzene.
The Department of Health and Human Services (DHHS) has determined that benzene causes cancer in humans. Long-term exposure to high levels of benzene in the air can cause leukemia, cancer of the blood-forming organs.
People who suffer from some auto-immune disorders (such as Sorgen’s Syndrome, rheumatoid arthritis, and Lupus) may be at a higher risk of developing some lymphomas than people who do not suffer from these disorders. Recipients of organ transplants also are more likely to develop lymphoma as are people with AIDS.
Even items intended to heal people may cause lymphoma. For example, there are associations between some prescription medicines—such as TNF Blockers—and lymphoma. Cancer treatments—such as chemotherapy and radiation—may cause some lymphomas as well. We know that some leukemias are the result of prior cancer treatments. Hardly a week goes without a news report about possible links between diet and cancer. Often these reports on diet and cancer yield inconsistent results.
Lymphomas are not contagious. But exposure to some bacteria and viruses causes some lymphomas. Epstein-Barr virus, for example, is linked to the endemic type of Burkitt’s lymphoma in Africa. In Western Countries, a very high percentage of patients with Hodgkin lymphoma have or had Epstein-Barr virus. Helicobacter pylori and Hepatitis C are also associated with some lymphomas. Simply stated, there are associations between exposures to toxins, viruses, and other substances and some lymphomas.
We know that there is more to the equation than exposures to toxins and viruses. After all, many people exposed to these agents do not get lymphoma and many people with lymphoma do not have known exposures to these agents. Our immune system plays a critical role in defeating cancer and lymphoma actually is cancer of the immune system. This is why understanding what causes lymphoma is critically important not only for lymphoma, but also for unlocking the mysteries to other cancers and other diseases. This is one of the many reasons why we say that lymphoma research is the super highway to curing cancer.
Fortunately, there are dedicated researchers around the globe investigating the causes of lymphoma. More importantly, they are working collaboratively—sharing their discoveries, statistics, and insights. Such collaborative efforts benefit all of us by hastening the pace of medical advancement. The International Lymphoma Epidemiology Consortium (InterLymph) is an international group of leading medical investigators engaged in research on the epidemiology of lymphoma. In 2013, they published papers on identifying sources of Chronic Lymphocytic Leukemia and the association of smoking and Hodgkin Lymphoma. We recently interviewed three such dedicated researchers on the Battling and Beating Cancer Radio Show and you can listen to that interview on demand at www.blogtalkradio.com/battling-and-beating-cancer.
Usually, when we discuss cancer research, the focus is on developing new and more efficacious treatments. But another critical aspect of cancer research involves the epidemiology of cancer—or the investigation into the causes of cancer. Understanding what causes cancer provides important insights into how to prevent cancer. It also fosters the development of better treatments.