Friday, 21 March 2014

Sensitive doctor

Supplementary material

Look, no matter what we do, we're going to die some day. Our mortal flesh did not evolve so that it would simply keep going on, but so we could reproduce and see to it that our offspring, in turn, had a good chance of propagating their (and our) genes. On an individual basis, we can already be glad that increased sanitation, better nutrition, protection from the elements and science-based medicine pushed back the average life expectancy to something in the early 80s, way after our ongoing existence can have a significant impact on the survival of grandchildren and great-grandchildren. In other words, we are blessed with longer lives than most of our ancestors could have hoped for, and it doesn't cost us much.

Unfortunately, there are circumstances that can cut short the thread of our life. Accidents, naturally, can put an end to our days suddenly and unexpectedly. Diseases, as well. In both cases, there are steps we can take to mitigate the risks.

Just one example: thanks to vaccination, we have destroyed or pretty much contained the monsters that were smallpox and tuberculosis. Consider the measure of our success: from a staggering death toll of 300 million people imputable to smallpox in the early 20th century, we went down to zero when it was finally eradicated in 1979. In fact, we were so successful in this endeavour that many people today fear vaccines more than they do the horrible diseases that they helped destroy; some will even go so far as to claim that these diseases went away by themselves. Oh, the humanity.

Other steps we can take to increase our chances of living a long life is to detect signs of certain cancers as early as possible. Cancer is, generally speaking, a disease involving cells that divide uncontrollably. This proliferation can disrupt the normal function of the body and lead to death. Now in many cases, the proliferation will start in one spot and form a mass of proliferating cells that we refer to as the "primary" tumour. The good news if we catch it at this stage is that we may be able to cut it out of the body, (provided it's not in some critical spot) and if we are able to remove all the out-of-control cells in the operation, then the cancer is gone. Were we to wait and wait and wait, we'd give the tumour the chance to shed some of its cells; these cells would travel around the body like dandelion seeds and start secondary tumours elsewhere. These new tumours, called metastases, are much harder to remove since there are so many of them all over the place. Hence the need for speed at the detection stage.

Some cancers with a high prevalence are, luckily enough, fairly easy to spot. Most men will undergo the uncomfortable and *ahem* invasive procedure that allow a doctor to check if the patient's prostate is hypertrophied, an early sign of prostate cancer. (The American Cancer Society states that prostate cancer is the second most common in American men, with 233 000 new cases and roughly 30 000 deaths annually out of a population of about 150 million).

Among women, the most prevalent cancer is breast cancer, with similar numbers: 232 340 new cases and 39 620 deaths in 2013. Self-inspection and mammographies are used to try and spot signs of a tumour, which would feel like a small hard mass. (Unlike prostate cancer, however, breast cancer does not restrict itself to mostly older people; its societal impact is therefore greater).

Although some men will also suffer from breast cancer, there are a few others that are restricted to women: endometrial cancer showed up in 49 560 new cases in 2013, a year that saw 8 190 lives lost to the disease. Ovarian cancer had 22 240 new cases and 14 030 deaths. Cervical cancer was found in 12 340 new cases and caused 4 030 deaths.

The good news regarding the latter is that we know pretty much how it develops: most cases are caused by a virus, the human papilloma virus (HPV). And we now have vaccines against the damned thing! With a little luck and if the anti-vaccine flat-Earthers do not convince too many people that vaccination causes spontaneous combustion of whatever disease is currently fashionable in the Hollywood jet-set, we may soon lower the death toll of cervical cancer to a tiny fraction of what it was in the past. (Men should also get vaccinated, since on top of keeping them from potentially infecting their significant other, it will also protect them from genital warts. Now there's a disgusting word).

Yes, but what about the rest of us who might already be carriers of the virus? That's where the Papanicolaou test (the Pap test, for short) comes in (pun unintended). The test relies on collecting cells from the endocervical canal and looking at them under a microscope. Pre-cancerous cells do not look like normal epithelial cells, and will inform the doctor and his patient that a more attentive scrutiny might be appropriate. This precautionary step can lead to a decrease of 80% in mortality!

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