So this will be my last post before the big Surgery tomorrow (Nov 23). Over the weekend I caught up with lots of friends (thanks to everyone who made it to our Thanksgiving BBQ) and the occasion reminded me of one question that I keep being asked: "why you?" i.e. why did you get stage 4 colon cancer at the age of 35.  

Good question, and obviously it's a question I've been thinking a lot about since I was diagnosed. It's the first question I asked my doctors when I met them and their response has been pretty consistent. They have all told me to just not think about it. Here's why. In some cases the cause of cancer is pretty obvious e.g lung cancer often (but definitely not always) caused by smoking, Mesothelioma generally traced back to asbestos exposure etc. However in most cases it's impossible to know. Modern medicine knows there are risk factors for certain cancers - genetics, obesity, diet etc - but it's generally impossible for a doctor to answer the "why you" question with any degree of precision. 

Despite the lack of a clear cut medical response, there is a natural desire to keep pushing for an answer to this question. For one thing, I really want to know how I can stop the cancer coming back if I'm lucky enough to survive this initial onslaught. So for this reason I've kept reading and I kept asking. 

Here are a few of my "findings" on the "risk factors": 

• Obesity - Now anyone that knows me knows that I've been, ummm, a little on the heavy side from time to time. Over the last 4 years or so I've been particularly bad. I had the whole dad body thing going on. A combination of kids at home and too many hours at work limiting free exercise time, working at Google (3 ridiculously good free hot meals a day), and exposure to "American eating" for 4 years (portion sizes, sugar in everything etc) all combined to lift me to my heaviest weight ever. So naturally, when I was diagnosed I thought my weight might be the cause. My doctors said this was unlikely. They felt I wasn't "obese" by the standard that would be a disease factor, and my weight hadn't been an issue for an extended period. Nonetheless, I personally feel being overweight must have been a factor and this has been a wake up call for me. No more excuses for being even a little overweight. Luckily cancer treatment is the ultimate weight loss program (at least for me). I'm down 12kg already and expect to lose quite a lot more post-surgery. 
• Diet - There is also the question of what you eat, but here again I don't seem to have a high risk factor. Do I eat some unhealthy stuff ? Sure ! I live for the perfect pain aux raisin (I can share my judging criteria for this wonderful class of pastry if anyone is interested). However I'm also a man who makes his own muesli (Granola for you American folk) and compared to the average family we eat pretty healthy (organic where possible, minimal red & processed meat etc). But here again Cancer has been a wake up call to do even more and so we've moved increasingly to a plant-based diet complimented by fish and even less red meat. 
• Stress - This is something I've reflected on quite a bit. I never considered myself "stressed", probably because my reference point is the stereotypical borderline suicidal overworked Wall Street executive, and by that measure I'm doing just fine. However in hindsight I realize I have been pretty stressed. When I first arrived in the US my role at Google was, ahhh, challenging. I walked into a total mess with a lot of important people applying pressure for quick resolution and no clear path forward. For about 6 months I was extremely stressed. In addition to that specific period I have a general on-going issue with imposter syndrome, which is heightened at Google where you're surrounded by A-type folk who seemingly all went to Harvard or Oxford - this means I operate with a higher than average baseline stress level. So, who knows what role this all played, but again I now know I need to manage stress extremely carefully and this is something I'm thinking a lot about when I contemplate my return to work. 
• Environmental exposures - I've done a lot of reading recently about how modern post World War II society has contaminated almost every aspect of our lives with chemicals - our food, our homes, our furniture, our water, cosmetics, cleaning products etc. Frankly, the more I learn the more horrified I am by what governments have permitted private industrial companies to pump into our food in particular. I think in the future, as medicine learns more about cancer, epidemiologists will almost certainly confirm a link between the alarming growth in the incidence of cancer and the tide of chemicals we've introduced into our lives. However until then this is another dead end in the search for a clear answer to the cause of my diagnosis. Nonetheless I plan to be much more vigilant about the products we allow into our home, and the products we use to build our next home. 
• Genetics - There is a ton of research happening in this space. I have no family history of this cancer but based on a 23andme DNA report I did several years ago (before 23andme were banned by the FDA from providing health risk reports), I do have a slightly higher genetic risk for colorectal cancer. After my surgery tomorrow my tumors will undergo a lot more genetic testing for what are called 'biomarkers'. There is a chance that they'll discover that I have something like Lynch Syndrome (I really hope not because this would be significant for my kids), but until then I have no reason to think my genes are the direct cause of me getting this cancer so early in my life. 

In addition to these very well established risk factors, not a week goes by where I don't read about another potential cause of cancer being unearthed by some "study". Here's just a sample: 

• Personality type - There is a whole body of research on 'Type C' personalities, essentially personality types that are cancer prone. I've reviewed some of this literature and it's a bit like reading a horoscope in that I think anyone could relate to some of the traits researchers have linked to increased cancer risk.
• Tattoos - I have a tattoo so this one got my attention. A study has suggested a possible link between tattoo ink and cancer later in life. Who knows but seems like a long-shot, at least in my case. 
• Processed meat - This one seems pretty well confirmed now. 

Incidentally, if anyone is interested in the latest information on cancer causes and how you can prevent cancer (including recommends for specific cancers) I think the best evidence-based resource is the American Institute for Cancer Research. 

One final thing I should mention is that there is an alarming increase in the number of younger people presenting with late stage colorectal cancers, enough to be causing serious concern in US medical circles. I suspect Australia and New Zealand will follow soon given their very similar rates of this cancer. Both the Washington Post and the New York Times have written about this recently. It's a bit of a mystery. I've joked that in 5 years they'll probably discover that eating a particular type of biscuit or drinking a particular beer was the cause - you know, something horrifyingly specific and avoidable. But in reality that's highly unlikely, it seems nothing is ever that clear cut in the world of cancer.