When The Oklahoman began profiling him in January 2009 in a series called "Life is real: writing the final chapters," Chastain believed he would be lucky to survive until May, when his oldest child was due to graduate from high school.
Chemotherapy slowed his cancer's progress, however, and he lived to celebrate his 46th birthday in December. That month, he posted on his NewsOK blog: "I'm still alive, but my health has really been slipping in the last two months. Hope to get some posts out soon, but I rarely feel like writing."
He is survived by his wife, LeAnn; a daughter, Maddye, and a son, Ford.
Plans for the funeral service are pending.