James, 80, underwent surgery earlier this month at Virginia Mason Medical Center, and is currently resting and recovering at home.
"Coach James and his family are grateful for the many prayers and encouraging words and ask that they continue. The family also asks for privacy as they fight this battle," his family said in a statement that was released by UW's Director of Athletic Communications Jeff Bechthold.
James' chemotherapy treatment is scheduled to begin Monday.
Don James served as UW head football coach for 18 seasons, from 1975 to 1992. He led the Huskies to a national championship in 1991, shared with Miami.
James' teams also won four Rose Bowls, the Orange Bowl in January 1985 and compiled a record of 10-5 in all bowl games. Overall, James tallied a winning percentage of .726 at Washington, including a then-record 98 wins in Pacific-10 Conference play. Washington won 22 consecutive games from 1990 to 1992.
James won national college coach of the year honors in 1977, 1984, and 1991. In 1997, he was inducted into the College Football Hall of Fame.