A deputy premier is facing her second cancer battle in three years as colleagues back in the "toughest and most resilient" member of their team.
Prue Car said her breast cancer was discovered during a recent screening and because it was caught early doctors were optimistic about her prognosis.
It is the NSW MP's second major health battle, having taken leave in 2022 after an unrelated kidney cancer diagnosis.
The mother of one, who entered state parliament in 2015 for the western Sydney seat of Londonderry, will remain as deputy premier despite the illness.
But she will step back from other ministerial duties, including in the key portfolio of education, while she undergoes treatment.
"I'm going to have to have a little bit of time off (and) I'm going to have to receive pretty significant treatment," Ms Car said in a video posted on social media on Tuesday.
"I've fought this before and I'm really confident I can fight it again, the prognosis is good and the amazing medical team around me are really hopeful about the prospects after treatment, and so am I."
Premier Chris Minns said Ms Car was "an absolute fighter" and would face her latest health challenge with determination and grace.
"Anyone in these circumstances, given she had to go through a similar challenge a couple of years ago, would be entitled to some self-pity ... but it's just not in Prue," he said.
"She will fight it, she's the toughest, most resilient colleague any of us have ever been in a team with."
Ms Car has been deputy premier of NSW since Labor won government in March 2023.
Fellow minister Courtney Houssos will temporarily take on her portfolios.
Breast Cancer Network Australia chief executive Kirsten Pilatti said Ms Car was one of the 58 Australians diagnosed with the condition each day.
"Our heart goes out to each and every one of them, and that includes the deputy premier," she told AAP.
"The earlier we can find a breast cancer, the better the outcomes will be for individuals.
"That means for people over 40, we're encouraging you to go through the BreastScreen program, and anyone who feels any kind of change should seek out information from your GP."
People over 40 should get a breast screening every two years although people with a higher risk should go more regularly.
Ms Car was a Penrith City councillor and national communications manager at MS Australia before entering parliament.
She was also an advisor to former NSW Labor premier Bob Carr from 2003 to 2005 and a party campaign co-ordinator from 2005 to 2007.
Alongside cabinet colleague and Treasurer Daniel Mookhey, the western Sydney MP has reached one of the highest levels of political office of any Australian of Indian origin.
Opposition Leader Mark Speakman wished Ms Car and her family well.
"On behalf of the NSW Opposition, and as a fellow MP, I know her community of Londonderry and colleagues will all be with her - and we're wishing her strength, care and a full recovery," he posted on X.
