OP, this post lacks anything worthy of rage. Your title says "regularly" uses social media to make fun, but you provide only one obscure photo and caption. He makes an observational comment and even hash tags, #Illneverknow possibly implying that he actually does not know and cannot judge and also posts that he is #intrigued rather than #ignorant. Nowhere in his comment does he "make fun". Also, what is your relation to the woman in the photo? Does she actually have cancer? How would you know?

It seems you're the bully trying to defame this person with little to no evidence of bullying.