Hello Dan,
Firstly, the most important thing is not to panic about prognosis - I gathered from your message this isn't currently an issue for you and it shouldn't be either. All things being equal, you will probably live a normal lifespan with a good quality of life **Key point for family to take note of**. It should also put your mind at ease a little, and as time goes on, you will become more comfortable dealing and living with CML. I forget about it most days and I'm now ~4 years since diagnosis.
I was diagnosed as a 32 year old, with similar conditions i.e. poorer running times, which i attributed to simply getting old. I was in the military at the time and so fitness was important to me then (and still is).
I'll try and answer your Qs in order:
1. Yes, me for one :-)
2. The only proven cause of CML is from ionizing radiation i.e. nuclear blast/fallout. I'm not sure if DU is ionizing or not. Benzene has been definitively linked to AML, but only tentatively linked to CML, so it is unproven at this time (companies have been successfully sued for causing CML by benzene exposure in the USA). However, I genuinely believe my exposure to aviation fuel was responsible for my CML. What good that does me is questionable, but it gives me a sense of possible explanation. I have a friend who has terminal lung cancer (never smoked) and he believes it was exposure to burn pits in Afghan.
3. My wife took my diagnosis quite hard, and probably still worries about it more than me. I quite enjoy the dark 'military humour' of saying "I can't believe you'd be so mean to a cancer patient" when i don't get my way. I think a lot of it comes down to mindset - I don't think of myself as a cancer patient day to day. The only time it really hits home is when I go to the doctor every three months for blood draw. In 6 months time you'll probably be feeling relatively normal i.e. 90%+ of what you were at 31 and as each day goes by you'll focus on CML less and less. Also, I think Leukemia is a nasty word - we call it Leonard instead. That way we can have conversations about Leonard in front of younger children or strangers and they are none the wiser. i.e. How is Leonard recently? Annoying, but minding his own business.
You're still a husband/father who can lead a relatively normal life, it's just there may be a couple of limitations you now need to consider i.e. tablets, fatigue, routine blood work.
4. I'm on Tasigna, which is the second generation after Imatinib. As for exercise, I strongly recommend it. I would ensure your last blood work confirmed your red blood cells are in the normal range, otherwise it gets really tiring really quickly. As counter-intuitive as it seems, if I'm feeling a bit out of energy and lethargic, the best thing for me is some running or a blast on my bike to get my heart rate up. I think getting your circulation going helps move the chemicals through your body (this is not scientific fact, just my old wives theory based on my experience). I still run and exercise, although not to the level I used to, it's more just for a bit of cardio fitness and muscle retention.
As for food, stay away from grapefruit as it interferes with the absorption of Imatinib, but that's about it. I found i suffered with heartburn more on the meds so have cut out spicy food and highly acidic stuff i.e. orange juice. I also went tee-total and have never felt healthier, but that's personal choice, not dictated by the meds.
5. As for staying in the army, I'm not sure what your medical grading system is like, so it is entirely dependent upon that. As for cardio fitness, I expect you will probably be able to maintain a level close enough to the standard to remain in service; however, there are times when i am simply exhausted and you need to consider the operational impact of this if it happens to you. If you're infantry, that could be a challenging existence; if you're in a more support-based role then coping with CML should pose few problems.
I struggled with coming to terms with some of the limitations CML imposed on me. I've since found it useful to focus on those things that are important to me and I've accepted I would find it difficult to run a 1/2 marathon again. I'm enjoying sports which are a little less physically demanding (I've stopped wakeboarding) and make the most out of quality time; the one thing CML did (which I'm grateful for) is make me appreciate what I have and I can look after my health from an early age. This is just my personal experience and I know several CML patients who are putting down some brilliant running/cycling times and simply getting on with it - entirely depends on how your body tolerates the meds.
If you have any questions, please feel free to ask.
Chris