Thanks for your good wishes all
My dad's 75 and has had a relatively happy and healthy life (he gave up the fags about 25 years ago I think and was never more than a 20 a day man, sometimes much less as he worked around flammable materials as a signwriter/maker), so this is ironic in a way. All told we have time and maybe remission or reduction can happen, so from that PoV it's bringing the family together and that can't be bad.
Radiotherapy is a double-edged treatment of course and I've heard good and bad reports, but the experiences of the two people I've known personally who've received it (for a brain tumour and breast cancer) both died and the lady with breast cancer found the treatment very painful and distressing (with lots of burning as you say Batty) and so her last days were a real strain on her and truly terrible for her family. But people's experiences differ, so maybe it won't be so bad.
Chemo's progressed a little in terms of pain mitigation and dosing, but the effect on the immune system at this time of year (it was confirmed at the beginning of Dec last) has taken a heavy toll with all the nasty bugs going around and so he's been in hospital three times for almost a week every time since New Year with raised temperature and the low levels in his blood. So I'm grateful that scientists have and are still developing medicines and treatments but nothing seems to be consistently 100% successful for everyone. At my father's age of course I know a lot of people opt to let the disease take its natural course after going through the treatment 'menu' as it were...
I think that this is what will happen with dad eventually and that will be really hard on my mum. But it's a choice most people will understand even though there is always something to 'fight' for. Some cures are calculable in terms of how great a price you want to pay for what in the end is only a limited time. The decision can be very easy, but living with it is hard for some who are left.
So Science is definitely good so far as its allowed to be. Facts can always speak for themselves!