Cancer epidemiology

Student guest post by McKenzie Steger Off the southeastern coast of Australia lies a small island that in the 1700 and 1800’s was inhabited by the very worst of Europe’s criminals and is now the only natural home in the world to a species named after the devil himself. Decades later beginning in 1996 Tasmanian devils were going about their nocturnal lifestyle in normal devilish fashion feasting on small mammals and birds, finding mates and reproducing, occasionally fighting with one another and so on. (1) Just as criminals divvied up their booty hundreds of years before, the devils were…
It's time for this year's second installment of student guest posts for my class on infectious causes of chronic disease. Fourth one this round is by Kristen Coleman.  If you are anything like me, you have been told countless reasons over the years why we must watch what we eat, keep our cholesterol intake down, and try to work out. It shouldn’t really come as a surprise then that I, since I am a public health student after all, aim to convince you of yet another reason why a healthy diet and exercise are valuable. What is this huge reason to avoid Big Macs and think about taking the stairs…
It's time for this year's second installment of student guest posts for my class on infectious causes of chronic disease. Second one this round is by Jonathan Yuska.  If you happen to be one of the 46 million individuals who have not been swayed to quit smoking by the countless anti-cigarette ads in print and on television, here is one more piece of evidence that may have you second thinking that next puff. On top of the more than 3,000 chemicals and heavy metals already identified in ordinary cigarettes1, upwards of a million microorganisms per cigarette have also been found to live and…
Third of five student guest posts by Dana Lowry In 1911, Peyton Rous first discovered viruses can cause cancer.  A chicken with a lump in her breast had been brought to Rous by a farmer.  Rous prepared an extract that eliminated bacteria and tumor cells and injected this extract into other chickens—tumors grew.  Rous suggested “a minute parasitic organism” was causing the tumor growth, which is now known to be a virus.  However, Rous’ discovery remained very controversial, and it wasn’t until 1966 that he was awarded a Nobel Prize for his discovery.  Since Rous’s discovery, researchers have…
Aah, the things one learns when awake at 3AM on a Saturday night. Via a few different Tweeps, I ran across this article from Men's Health magazine, titled "Urgent Warning: Sex with Animals Causes Cancer." I probably should have just stopped there. But no, I read the magazine article, which states: Brazilian researchers polled nearly 500 men from a dozen cities, and found that--we're not joking around here--roughly 35 percent of the men had "made it" with an animal. That's a problem, because screwing a horse, donkey, pig, or any other animal was found to up your likelihood of developing…
Student guest post by Desiré Christensen Colorectal cancer (aka colon cancer) includes cancers of the colon, rectum, and appendix. Colorectal cancer is more common in developed countries (e.g. United States and Japan) compared to developing countries in Africa and Asia. Each year in the United States, there are around 150,000 cases of colorectal cancer diagnosed and about 50,000 people die from this cancer. Risk factors for colorectal cancer include lifestyle factors (e.g. habitual alcohol use; high-fat, low-fiber diet; obesity; sedentary lifestyle; smoking), family history of intestinal…
Student guest post by Andrew Behan Malignant Mesothelioma (MM) is a rare type of cancer which manifests itself in the thin cells lining the human body's internal organs. There are three types of MM; pleural mesothelioma, peritoneal mesothelioma, and pericardial mesothelioma, affecting the lining of the lungs, abdominal cavity, and lining of the heart, respectively (1). Pleural mesothelioma is most common, consisting of about 70% of all MM cases and has a poor prognosis; patients live a median time of 18 months after diagnosis. (Note: for the purposes of this article, MM will be used to…
Student guest post by Francis Mawanda If you are like me, you probably always and almost faithfully, include a bottle of mouthwash on your grocery list especially after watching and/or listening to the numerous commercials in the media which claim that you will not only get long lasting fresh breath, but also freedom from the germs that cause plaque and gingivitis. However, many proprietary mouthwashes including my favorite brand contain Alcohol (ethanol) which also gives them the characteristic burn we have to endure, albeit for a few seconds each day, but safe in the knowledge that the…
Student guest post by Desiré Christensen Human papillomaviruses (HPVs) are small DNA viruses that infect epithelial cells. There are well over 100 subtypes of HPV. The subtypes that infect cutaneous epithelia are termed beta-HPVs and those that infect the mucosal epithelia are termed alpha-HPVs. Some alpha-HPVs have received attention as strong risk factors for the development of cervical cancer. Less public awareness has been generated over the role of HPVs in the development of other cancers such as vulvar, vaginal, anal, head and neck, and penile cancers. Only recent research has…
Student guest post by Anh To. When I found out my only non-smoking cousin had nasopharyngeal carcinoma (NPC), I was puzzled. With all the hype about cigarette smoking associated with various kinds of cancers in the media, I did not understand why none of my smoking cousins had NPC but the one who didn't smoke did. At first, I thought it must be due to the second hand smoke. Now, I understand that the picture is very complex. Before I go into what I have learned over the past several months, I need to make a disclaimer. I am not an expert in NPC. I am an average college student. This…
Helicobacter pylori is, by bacteriological standards, a relative newcomer to medicine. Although its pathogenesis has been studied for only about the past 20 years, there are reports from as far back as the late 19th century of small, helical bacteria in the stomachs of some patients. Largely these anecdotal reports were relegated to the "hmm, interesting" file and not followed up for many years. It wasn't necessarily that others didn't follow (or care about) the research; the lack of studies on them, despite occasional reports in the literature, is probably due more to the fact that we hadn…
This is the third of 6 guest posts on infection and chronic disease. Does chronic IL-6 levels lead to epigenetic changes in DNA methylation that contribute to this pathway? By Matthew Fitzgerald How can infection be a carcinogen? How do infectious diseases lead to cancer, if at all, is still a highly debated area of research. Do infectious diseases change the genetic information by insertions, mutation, or do bacterial toxins act as carcinogens? Does inflammation lead to free radical damage and cancer? While all of these and more are possible causes, another potential mechanism is that…
It's just not been Vegas' week. First a ricin-laced hotel room, then a clinic-associated outbreak of hepatitis C virus (and potentially hepatitis B and HIV) that could become enormous. Meanwhile, an outbreak of hepatitis E is raging in Uganda. So what are these virues, and how in the world could a medical catastrophe of this magnitude happen in the U.S.? More after the jump... The group of hepatitis viruses (A, B, C, D, E, and G) are related in name only. They've all been either associated with or found to cause hepatitis--inflammation of the liver. This can be acute inflammation (short…
This is the sixth of 6 guest posts on infectious causes of chronic disease. By Ousmane Diallo I was dumbfounded when I read this news article relating HPV to the increase of lip and oral cancers because of oral sex. It reminded me my younger years, as a med student, debating with my professor of psychology the fundamentals of Freudian psychoanalysis, the Id, the Ego and the Super-ego. It was a rather philosophical debate more than anything else, a combination of religious and cultural reciprocal statements of beliefs. At that time, we were exposed to the new French "sexual education"…
This is the first of 6 guest posts on infectious causes of chronic disease. by Matthew Fitzgerald Viruses cause cancer? Cancer researchers have for decades known that viruses can cause cancer. It is now estimated that 15% of the world's cancers are caused by infectious diseases including viruses. Some of these include: Human Papilloma Virus (HPV) and cervical cancer; Epstein-Barr Virus (EBV) and nasopharyngeal cancer & lymphoma; Hepatitis B and liver cancer. In fact cancer researchers use this knowledge of viruses causing cancer by utilizing EBV and SV40 and other viruses to "…
Last month, I wrote an update on the strange cancer affecting Tasmanian devils--a tumor cell that's taken on a life of its own, and is spreading through the population as the animals fight. Now, via PZ comes something you can do to help--donate and help to save this species: Help the Tasmanian devil with 6 top funding priorities: 1. Investigating the tumour and its chromosomes, looking for clues to resistance 2.Keeping some area or areas of Tasmania free from the disease i.e. wild management 3.Maintaining backup captive populations of devils in Tasmania as 'insurance' 4.…
Following a new PNAS paper regarding the strange facial cancers in Tasmanian devils, I have a post on the topic up over at Correlations. (Be sure to check out the Correlations homepage too!)
Last year, I mentioned some ongoing research suggesting a link between exposure to light and the development of breast cancer. As I mentioned then: While we know a good deal about factors that can contribute to breast cancer risk--including genetics (such as mutations in the BRCA1 and BRCA2 genes) and lifestyle choices (late or no childbearing, high fat diet, lack of exercise), many environmental risks for breast cancer remain controversial. Even the effect of cigarette smoking on breast cancer development remains uncertain, as does the environmental light idea. For a nice update and…
A few readers have asked me what I thought about HIV "dissident" Peter Duesberg's recent article in Scientific American, entitled Chromosomal Chaos and Cancer. Duesberg's cancer ideas--and his claim of novelty for researching how chromosomal abnormalities, rather than more simpler gene mutations, cause cancer--are something I wanted to write about months ago, after I came across an interesting reference in this post over at Panda's Thumb, where it was noted that "...in certain kinds of cancer, chromosomal instability prevents tumourogenesis, the exact opposite of what Wells [and Duesberg--TS…
Last summer, I mentioned that groups receiving federal funding were providing misleading information about abortion, including the unsupported statement that having an abortion increases the risk of development of breast cancer. As I noted, this "link" has been refuted by a number of analyses, including a 2004 Lancet paper and a 2003 National Cancer Institute report. As if those weren't enough, a new study comes to the same conclusion: yep, no link. More after the jump. The new study, appearing in Monday's Archives of Internal Medicine, looked at data from 105,716 women participating in…