The Prime Minister Boris Johnson said Brokenshire, who had never smoked, had led a "heroic" fight against cancer.
Johnson added: "Desperately sad to hear the news about James Brokenshire. James was the nicest, kindest and most unassuming of politicians but also extraordinarily effective."
Brokenshire was the Conservative MP for Old Bexley and Sidcup, the former constituency of Edward Heath. A by-election will be fought later in the year or in the spring.
In July Home Secretary Priti Patel took over the security minister portfolio after it became clear Brokenshire was not well enough to return.
The security minister brief outlined on the government’s website is extensive. Responsibilities include counter-terrorism, serious and organised crime, cybercrime, economic crime, hostile state activity, extradition, and royal and VIP protection.
It also covers online harms; the common travel area between the UK, Ireland, the Isle of Man and the Channel Islands; aviation and maritime security; Grenfell; and flooding, hurricane, and natural disaster relief.
During the Covid-19 pandemic, the minister also oversaw the functioning of the domestic national security system, including MI5, counter-terrorism policing, as well as the functioning of the serious and organised crime system, including the National Crime Agency, and cybersecurity.