She was promoted to secretary of state for culture, media and sport in the government reshuffle in July 2016.
In November 2016, she drew criticism for vetoing the appointment of a black female candidate as a non-executive director of Channel 4, while confirming the appointment of the other four candidates, who were white men and the decision was reversed the following year.
He wrote: "In the last few days I have been told that I have a small lesion in my right lung which needs to be removed".
The Shadow of State for Northern Ireland, Owen Smith, said he was very sorry to hear Mr Brokenshire has left the cabinet and wished him a speedy recovery.
"Clearly, my long term health and my family are my priorities and I intend to proceed with surgery at the earliest opportunity", he continued.
The British and Irish Governments had been expected to kickstart another bid to restore devolution after several rounds of talks past year failed to produce a deal between the DUP and Sinn Fein.
Since then, he has assisted efforts to restore power-sharing in the country.
Talks are still stalled on two key demands from Sinn Fein, which backs the legalisation of same-sex marriage and legal protection for the Irish language. However, a deal has yet to be struck.
He was seen as a crucial minister at Stormont where the devolved Northern Ireland assembly is now suspended following a fall-out between the Democratic Unionist Party (DUP) and the pro-republican Sinn Fein.