The Masked Singer winner, 34, shared her heartbreaking response on Twitter to show her support for her former bandmate Girls Aloud.
Nicola reiterated that Sarah was “so loved and supported” during this difficult time in a heartwarming tweet on Wednesday.
She wrote: “It goes without saying that this is blind. @SarahNHarding you are so loved and supported. “
Nicola has teamed up with her ex-bandmates Cheryl, Nadine Coyle and Kimberley Walsh to show their public support for Sarah.
It comes just hours after Sarah told her fans about the devastating news on Instagram after stepping away from the spotlight in recent months.
The singer underwent weekly chemotherapy sessions in an attempt to fight the disease.
Her full Instagram statement read: “Hello everyone, I hope you are all doing safe during this time of uncertainty. Haven’t posted here for so long, thanks to everyone who contacted me, it really means a lot.
“I think it’s a good time to share what’s going on. There’s no easy way to say that and in fact it doesn’t even feel real to write this down, but there you go.
“Earlier this year I was diagnosed with breast cancer and a few weeks ago I learned the terrible news that the cancer had spread to other parts of my body. I am currently on weekly chemotherapy and am fighting as hard as I can. can.
“I understand that this can be shocking to read on social media and that it really isn’t my intention. But last week it was mentioned online that I had been seen in the hospital, so I think it’s time to let people know what’s going on. and that’s the best way I can think of to do it.
“My mother, family and close friends are wonderful helping me through this situation, and I want to thank the wonderful NHS doctors and nurses who have been and continue to be heroes.
“I’m doing my best to stay positive and will keep you posted on how I’m doing. In the meantime, I hope you will all understand and respect my request for confidentiality during this difficult time.
“Sending all of you so much love… .xx. ”
Kimberley, Cheryl, Sarah, Nicola and Nadine rose to fame as the five-piece Girls Aloud group.
The chart-topping group was formed on ITV Popstars: The Rivals in 2002.
They reunited in 2012 but the group broke up for good in 2013.