Famous US actress Olivia Munn reveals devastating cancer diagnosis [Video]

John Mulaney has praised his girlfriend Olivia Munn for “fighting so hard” during her battle with breast cancer.

The 43-year-old actress revealed on Instagram on Wednesday that she was diagnosed with the disease last year after undergoing a series of tests, which ultimately led to her having a double mastectomy.

Munn’s former Saturday Night Live star boyfriend — with whom she has two-year-old son Malcolm — has offered a public show of support.

Commenting on Olivia’s lengthy social media post, John wrote: “Thank you for fighting so hard to be here for us. Malc and I adore you. [heart emoji] (sic)”

The Newsroom actress had explained she had undergone genetic testing that screened for “90 different cancer genes” and was relieved for them all to come back negative.

However, a simple risk assessment then flagged that she had an almost 40 percent chance of developing cancer within her lifetime, prompting …