Within one day, more than 665 people have joined a Facebook group praying for Walker County Sheriff Steve Wilson.

Sheriff Wilson joined a Multiple Myeloma Research Foundation group on the popular social networking Web site. He posted on Sunday that he was diagnosed with the disease last week and would begin treatments Monday.

He ended the post by saying he was "scared but optimistic."

Sheriff Wilson could not be reached for comment Tuesday.

With multiple myeloma, plasma cells within bone marrow begin to grow out of control, according to the American Cancer Society's Web site. The disease can create too many plasma cells, causing a decrease in both white and red blood cells. That can lead to anemia, bruising or bleeding and difficulty fighting infections.

The overgrowth also can break down old bone without new bone growing to replace it, making bones weak and easily broken, according to the site.

Hundreds of members have joined the group "Praying for Steve Wilson & Family" since its first post Monday.

Missie Swanson Kendrick wrote, "Our thoughts are with you and your family as you begin your journey."

Virginia Scott wrote, "You are a can-do kinda of person and will hit this dreaded disease head on."

Many simply posted that they would pray for the sheriff. The group noted that the treatment regimen should continue for the next six months.