The former Labour MP for Kensington has revealed she underwent treatment for breast cancer days before narrowly losing her seat to the Conservatives in the general election.

Emma Dent Coad told the BBC she received the diagnosis after a routine screening on 14 November and underwent a procedure to remove the cancer three days before polling day.

The 65-year-old, who is still a Labour councillor in the London borough of Kensington and Chelsea, said she decided not to share the diagnosis with the public, because she didn’t want it to become an issue in the campaign.

Dent Coad was elected as the seat’s first Labour MP in 2017, a week before 72 people were killed in the fire at Grenfell Tower in the constituency. She lost the seat by 150 votes in last week’s general election.

“I was very lucky, it was picked up very early after a screening. It was pre-lump stage,” she told the the BBC’s Victoria Derbyshire. “I always knew it was a possibility. I have four sisters, two of them have been through it and survived […] I was hoping I had got away with it.

“I’m OK, actually, because I’m going through the process and I feel quite positive about it. But it was a horrible shock at a really terrible time.”

Dent Coad said part of the reason she had decided not to make her diagnosis public was because she and her family needed time to deal with the news. “[It was also] partly because I just didn’t want it to be a factor, at all, either positive or negative, in my campaign,” she said.

“I didn’t want it to be an issue at all, so we had organised everything beautifully and I just stepped out when I had to and the machine of the campaign continued around me, and [I pay] tribute to those people who did that.”

Speaking earlier this week, Dent Coad said part of the reason she lost her seat was because of claims by remain-supporting advocates of tactical voting that her Lib Dem rival, Sam Gyimah, was the most likely candidate to beat the Tories.

“People believed it,” she said. “Some of my own friends did, they voted Liberal Democrat. They said: ‘I’m really sorry Emma, but I’ve seen the polling. You can’t win.’ And I lost by 150. Only 76 people needed to think: ‘Give us a break’ and I would have been back in.”