Last updated on December 4, 2020
Yes. Facebook agrees that undergoing a mastectomy is a life-changing experience and that sharing photos can help raise awareness about breast cancer and support the men and women facing a diagnosis, undergoing treatment or living with the scars of cancer. The vast majority of these kinds of photos are compliant with Facebook policies.
Source: https://www.facebook.com/help/318612434939348?helpref=uf_permalink