Preference my remarks with I'm not a doctor or anything close to one but I personally feel that stress can diminish the effectiveness of our immune system and to the extent that a virus may cause cancer then it is conceivable that the virus may be able to do it's damage when possibly it wouldn't have been able to without a stressed mental state.

As far as you wanting to take responsibility for your mom's cancer I believe it's just your guilt looking for closure which to me is a positive sign and I would redirect that by telling her (every day for a while if that's what it takes) that you are sorry for any pain/suffering you may have caused her when you were going through a rough period.

David

Age 58 at Dx, HPV16+ SCC, Stage IV BOT+2 nodes, non smoker, casual drinker, exercise nut, Cisplatin x 3 & concurrent IMRT x 35,(70 Gy), no surgery, no Peg, Tx at Moffitt over Aug 06. Jun 07, back to riding my bike 100 miles a wk. Now doing 12 Spin classes and 60 outdoor miles per wk. Nov 13 completed Hilly Century ride for Cancer, 104 miles, 1st Place in my age group. Apr 2014 & 15, Spun for 9 straight hrs to raise $$ for YMCA's Livestrong Program. Certified Spin Instructor Jun 2014.