Applegate underwent the procedure in 2008 after doctors detected a small lump in her breast during a routine medical screening, and she was later given a clean bill of health due to the life-saving procedure.
Bates was diagnosed with breast cancer earlier this year (12), prompting the Misery star, who beat ovarian cancer in 2003, to weigh up her treatment options - and she called old pal Applegate for help as she made her decision.
A source tells the National Enquirer, "The two have been friends for years, and Kathy was especially supportive of Christina during the days of her health crisis... Christina's example was a lifesaver for Kathy."
The 64-year-old Oscar winner went public with her breast cancer battle during a U.S. magazine expose earlier this month (Sep12).
