I read some very interesting news this week about cancer that brings a whole new meaning to the expression "I'd rather be lucky than good", and how that relates to our chances of falling victim to cancer in our lifetimes. Those odds are already pretty heavily stacked against us, with an estimated 40% of adults predicted to stumble into some form of the deadly disease at some point or other in their lives.
What is apparently shocking in the article published by Tomasetti & Vogelstein in "Science" magazine this past week is that it essentially debunks the "myth" that we are born genetically predisposed (or not) to (a particular) cancer, and when that is the case and is in combination with the right (i.e. wrong) environmental cues - then we get cancer. This thinking did not change with the sequencing of the human genome, which, although it simplified us in terms of how many coding genes we express, left us as in the dark as before regarding our susceptibility to killer diseases such as cancer.
Although we have gotten a lot more successful in treating various types of cancer, it remains the #2 killer in North America after cardiovascular disease, and we still understand very little about what precisely causes it. Gaining a firmer understanding of what changes in a previously healthy body that results in that body's cells being instructed to eat the organism alive from the inside out has always been the holy grail of trying to detect and prevent cancer before it gets too tight a grip.
Whilst cancer research has continued on as aggressively as cancer itself, in spite of many billions of dollars spent on it, there are few certainties about the crossroads between life and death that is cancer. What we do hear most frequently from our doctors is not to smoke, eat a healthy diet rich in fibre, vegetables and fruits, get as much exercise as we can, and sleep deep for several hours a night - all of this is supposed to up our chances of never having to face the grim reaper diagnosis that is cancer.
And yet we remain bombarded by all sorts of examples that don't fit the hypothesis and hear all the stories about people who spent their entire life "breaking the rules" yet living well into their nineties, while your super-healthy next door neighbour or colleague across the corridor dies at forty-one from cancer. It's often even more shocking when that person's parents are still alive and well, and the family has no history of cancer. There just has to be more going on than good or bad genes and heredity - according to Bert Vogelstein at least.
The rather startling news from Vogelstein (and Tomasetti) of Johns Hopkins University is that one reason why we may have been digging in the dark with little success is that in about two-thirds of cases, it all comes down to luck. That would be bad luck, of course! The authors report that the frequency of cancers seen in a particular tissue correlates with the total number of cell divisions of stem cells present in that tissue, and it therefore implicates that cell division as causative in the disease.
Given that random mutations are introduced into our DNA when it replicates, it appears that it is that very randomness and the statistical possibility therein of introducing a negatively-impactful mutation that is at the root of the problem, almost 70% of the time. The introduction of that mutation and its propagation into future generations of daughter cells is presumed to be the mechanism by which the body ultimately turns against itself - all as a result of mere bad luck?! It's an initially bizarre-sounding hypothesis, and yet it explains much that has heretofore confused research scientists and clinicians alike. Bert Vogelstein recently summarised it as follows:
"All cancers are caused by a combination of bad luck, the environment, and heredity."
It's a very provocative statement, and may tempt some to claim that they knew the doctors and scientists were full of it all along, so now they can go back to living their life as they want and taking their chances with the lottery of life and death that is bad luck and cancer. However, even if two-thirds of it does stem from stem cells and bad luck, it is worth noting that the environment is still in there, and you might not want to add a bad environment into the equation of a bad luck mutation and it's chances of causing cancer.
More research is needed, of course, and we will need to get better at earlier detection and diagnosis of various cancers, as well as identification of those random mutations that are devastatingly consequential in terms of entirely unpredictable emergence of cancer. In the meantime, it looks like we remain stuck with the dreaded treadmill or sidewalk, the chewy fibre and vegetables, and the reluctant putting down of bad habits - if we want to continue to win at and hurdle any bad luck in the lottery of life!
No comments:
Post a Comment