I saw an article on a yarn store called On The Lamb, located in Uxbridge, Ontario. A Knitted Knocker is a knitted prosthetic breast for a mastectomy patient. It's lighter and cooler to wear than a silicone prosthetic, and it's much less expensive - according to the article, one of those can cost $300 to $500.
I don't knit - alas, I tried, and never got the hang of it - but if you do, you can go to the website and download a pattern for one. There's also a pattern for a chemo cap. Knitters close to the store can drop them off for donation to patients at Toronto's Sunnybrook Hospital. If you're not, maybe you could call your local hospital and see if there's any interest in setting up a program for these.