Pinpointing a cause of cancer? Not so much, Mr. Douglas.

Michael DouglasStefanie Joelle Kuzmiski, B.Sc.

Michael Douglas is currently trying to backtrack on statements made during an interview with The Guardian, where he discounted his history of smoking and excessive alcohol consumption as contributing factors for his cancer. When asked about his cancer, Douglas replied, “without wanting to get too specific, this particular cancer is caused by HPV (human papillomavirus), which actually comes from cunnilingus.” The issue with this statement isn’t linking HPV to throat cancers; rather, it is pinpointing cause. Although there is a correlation between HPV and some forms of throat cancer, it should be made clear that pinpointing a definitive singular cause is impossible.

HPV enters into epithelial cells (cells that line human extremities and cavities, including the walls of our throats, genitals, and anus), where it begins to make proteins that affect cell cycle regulation.  Cell cycle regulation helps to determine the growth and division of the cell. Cells that are infected by HPV have their cell cycles manipulated, which can put them at an advantage for growth compared to other cells. This seems great, but it is really the root of all cancers. Too much growth is bad, and these viruses enable rapid growth which can cause major problems when unrecognized by our immune systems. As these HPV infected cells continue to grow and divide, smoking would only exacerbate the problem, potentially causing mutations that also affect the cell cycle. All things considered, identifying a cause of cancer is incredibly difficult and part of the reason why cancer research is so complex. Increased exposure to carcinogens certainly doesn’t help and could potentially lead to mutations that cause even greater cell proliferation and tumours.­

One thing to get clear is that mutations rarely lead to tumours and “tumour” is not synonymous with “cancer.”  There are many misconceptions about causes of cancer and risk factors associated with various chemicals. Some of these factors have a real scientific basis (such as chemical carcinogens in smoking) while others have absolutely none (such as the Daily Mail’s report that Facebook causes cancer).  Manyindividuals are targeting Douglas for not addressing his past substance abuse.  However, I think this leads into larger questions about patient education.  Why did Douglas think that smoking was not a possible contributing factor? Isolating the cause of cancer is too difficult, and sometimes a mutation that leads to cancer is just dumb luck. Providing patients with this understanding that chance plays a large role in how cancers develop reveals a fundamental randomness to this terrible illness. It makes us aware that there is still so much about cancer development that we are struggling to understand. This lack of clarity could be discouraging, but it is also the reality. Cancer needs to be approached and understood as a complex illness, without any possible easy explanation and without the overemphasis of singular causes. The only easy answer I have is that surfing around on Facebook isn’t going to give me a tumor any time soon.

3 responses to “Pinpointing a cause of cancer? Not so much, Mr. Douglas.”

  1. Jason says:

    Actually, the molecular signature of an HPV-positive tumour is different from that of an HPV-negative one. In practice, when the surgeons removed the malignant growth, it would have been analyzed by a pathologist, an analysis that would include looking at molecular markers. Thus, while it’s true that at the time of diagnosis, a history of smoking and alcohol consumption could have been just as likely an etiological candidate as HPV, once the pathology results were available, the treating physicians would have been able to tell him that the cancer was most likely a result of HPV infection (head and neck tumours arising from HPV infection also tend to show different clinical patterns in terms of the exact anatomical sites where they grow, the time course of lymph node metastasis, etc., which may have been confirmatory signs).

    Thus, while it may be true that, for a specific cancer, it isn’t possible to say with 100% certainty what the cause was, in practice, in this particular type of scenario, doctors can with some confidence determine the most likely cause. This is important, clinically, because the prognosis for HPV+ and HPV- tumours is different and it’s the doctor’s responsibility to counsel the patient regarding prognosis.

  2. Madeline O'Connor says:

    I have seen several comments with similar opinions in the news recently responding to Mr. Douglas’s interview. While smoking and alcohol use are unquestionably factors increasing one’s risk of head and neck cancers, there is a definite rise in the incidence of esophageal cancers, and this is thought to be linked to HPV. Rates of smoking have declined, while rates of squamous cell carcinomas of the head and neck have increased. Furthermore, cervical and anal cancers are almost exclusively caused by HPV, although smoking increases their likelihood. Nowadays, the molecular “fingerprint” of cancers can often be identified by a pathologist and certain virally-induced cancers may distinguished by a pathologist. While lifestyle choices can influence our risk of cancer, the fact that malignancies are, for the most part, random events is difficult for the public to accept. The great majority of people affected with HPV will not develop cancer, and the majority of smokers will not develop lung cancer. However, it is quite likely that Mr. Douglas’s physicians have been able to establish that his cancer was HPV associated. Perhaps awareness of this issue will help with acceptance of vaccination campaigns to protect future generations against this virus. In areas where there has been wide use of HPV vaccine, rates of cervical cancer have dropped drastically, and, one would expect rates of esophageal and anal cancers will decline as well. – Madeline O’Connor, GP Oncologist

  3. Katherine says:

    If you study our medical care system you’ll find you will find numerous health problems we endure from that we do not have a remedy for, the common cold being just one of them. Also there are many health issues we do have drugs for but these drugs do not remedy but merely control the symptoms. Asthma and diabetes are a couple and individuals with those issues are often on a lifetime of medication that is good business for the companies that are supplying the drugs.If we weren’t trying to create a profit from cancer we would have a remedy for it tomorrow because nature features a remedy.

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