It's a wonderful cause. My mum used to have long hair. When my sister was diagnosed with cancer a few years ago (she has since recovered), Mum cut off and donated her hair in solidarity. (Sister didn't need chemo, just radiation, and she had minimal hair loss, but Mum wanted to show her support.)
Here in Canada, we have an annual cancer event. It's called Terry Fox Day, in honour of a young man who tried to run across Canada in a "Marathon of Hope" to raise money for cancer treatment in the 1980s. He himself had osteosarcoma, a form of bone cancer, and ran with an artificial leg because of it. Unfortunately he wasn't able to complete his journey as the cancer spread to his lungs, but his legacy has led to the annual Terry Fox Run and the Great Canadian Head Shave, both of which raise money for cancer research.