Do you think stress can cause / trigger / accelerate cancer?

I definitely agree that stress weakens your immune system, and insomuch as cancer in general is seen as: 

"any one of a large number of diseases characterized by the development of abnormal cells that divide uncontrollably and have the ability to infiltrate and destroy normal body tissue"

then I do believe that stress can contribute to 'giving' you cancer, in a very general sense.  If your immune system can't handle things due to stress, then the abnormal cells could sneak thru the normal processes your body would go thru to protect itself.  Environmental and hereditary factors, etc. are also important, but I do think stress can play a part in causing your cells to 'go crazy' and turn into cancer.  (this is non-scientific; this is just what I think.)

eta:  and I don't see it as 'you caused your own cancer' but more like something that shows differences in how people's immune systems work.  

Possibly. I'd rather trust the scientific studies than my or other non-scientific opinions.

Also, childhood cancer makes me doubt the link somewhat. Also makes me doubt other things.

"In the United States, about 3,500 children are diagnosed with leukemia each year. Leukemia is the most common childhood cancer, making up about a third of all pediatric cancers. In the United States, about 3,500 children are diagnosed with leukemia each year."

www.mdanderson.org/cancer-types/childhood-leukemia.html

good point; I hadn't thought about that segment of cancers. I was only thinking about adult-onset cancers.

i don't think it brings it on. however it may exacerbate the symptoms and affect your ability to deal treatment if your mind and emotions are affected by stress. you may sleep well, eat well, or get enough rest.