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