In his first broadcast interview since surgery to remove a tumour, he confirmed for the first time that he had cancer, and told Sky News he feels lucky to have been diagnosed early.
Mr Brokenshire, who has never smoked, returned to Westminster this week just five weeks after having the upper lobe of his right lung removed at Guy’s Hospital in London.
His rehabilitation is ahead of schedule and his prognosis is good, with doctors confident that the cancer was contained.
But he conceded the diagnosis had taken him to “dark places”, and said support from his family, and from across the political spectrum, had been invaluable.
“It has been a hard few weeks. I’ve had surgery to remove the upper lobe of my right lung, and was fortunate for have an amazing surgeon and incredible support from the NHS team at Guy’s,” he said.
“It was quite a shock. You don’t think that sort of thing would happen to you and it’s quite something to go through.
“Reflecting now, I feel that I’m lucky that it was at a very early stage, it was in a place where surgery was available, but yes, it potentially takes you into some dark places.
“And it’s not just about you, it’s about family, Cathy [his wife] and the children and the impact it has on them. They’ve been an incredible strength to me.
“The love and support that they’ve given to me, I’m quite sure that I couldn’t have got through it in the way I have and maintained the positive outlook I have, had it not been for them.”
Mr Brokenshire first became concerned before Christmas when he cleared his throat and noticed a small amount of blood in his tissue.
It was his only symptom but it prompted him to visit his GP, who referred him for a series of tests.
The diagnosis process took place while Mr Brokenshire was at the heart of intense discussions over both power-sharing in Northern Ireland and Brexit.
The definitive test came the morning after he was part of the team in Downing Street finalising the phase one agreement with the European Union.
“The easiest thing in the world for me to have done would have been to say, ‘sorry I’m too busy, we’ll put this off’. If I had, who knows what the prognosis or the outcome would have been.
“But I put my health first and I suppose that’s a lesson for all of us. Your health is your priority. Without that where would any of us be?”
Before he underwent the surgery, Mr Brokenshire told Sky News about the “jolt” he experienced after being diagnosed. He hopes his case can be an example to others.
“I think we need to promote that lung cancer is about early diagnosis, about awareness, about ensuring there are the right pathways to get the clinical interventions that are needed.
“And also to break some of the stigma around lung cancer, because around 15% of cases are in non-smokers, people who have not smoked at all and yet there is this assumption that it must be your fault in some way. And we do need to break that.”
Mr Brokenshire will focus on his constituency work from the back benches while his rehabilitation continues, and has no regrets about stepping away from Cabinet amid momentous political events.
“You have to be well. Look at the situation in Northern Ireland now, where sadly we still do not have agreement. You owe it to everyone to be able to give it 100%, and I could not do that so I have no regrets.”
Health permitting, he is determined to return to the political front line in due course, however, and, as a long-term ally of the Prime Minister’s, many in Westminster consider he has every chance.