Is this an accurate recount of what it is actually like for kids/young adults with Cancer?

I've never really been exposed to support groups that work with youth, cancer patients, but the first time I read the novel, I found it to be very genuine and believable. In addition, Green based the novel on his own experiences during the time he worked as a chaplain in a children's hospital, thus, in writing the novel, he drew from his own personal experience. So, in answer to your question, I'd have to say yes.