The King, who had been taken into hospital for an enlarged prostate in an unrelated medical visit just two weeks ago, has been advised to step away from public-facing duties while he undergoes treatment.
Two sisters, 49-year-old Julie and 54-year-old Arlene, both nurses from Northern Ireland, flew out from Belfast after hearing the news.
“We booked flights straight away. It’s a big shock. It’s huge. He’s waited so long to be on the throne and now this happens. It’s crazy,’ Julie said.
“We both come from Belfast and from a very young age, from the early 1980s with Charles and Diana’s wedding and then Andrew and Fergie - I just remember all their weddings and street parties. We grew up with that and all the memorabilia. It’s just so sad to come on this occasion.”
Charles, who had his coronation just nine months ago, ascended the throne after a 70 year wait following the death of his mother Queen Elizabeth II - the longest reigning monarch in British history.
Mother and daughter Jacqueline Murray, 40, and Nicola Roberts, 60 said the diagnosis being made public made Brits see the family as more relatable.
“Charles’s diagnosis makes him more relatable to the rest of us. Other people have been affected by cancer and you don’t hear about it happening to the royal family.
“It shows they get affected by the same things as the rest of us. It’s very sad and we wish him well.”
Others felt the King’s openness to share his medical journey made the royals appear more human
“I think it makes him more human. Anything that comes out of it is a positive, because lots of people don’t think about these things until they see someone in the public and then it makes them think about it,” said Tenelle, 42.
Charities reported there had been a surge in men being checked for prostate cancer risk following the King’s hospitalisation a fortnight ago, although it is unrelated to his current cancer diagnosis.
Constantine Saur an 18-year-old exchange student from Germany and said that the news would be a “wake up call” for other men of all ages.
“Sometimes it takes a celebrity to have something for other people to get checked and to take their health more seriously,” said Constantine.
“I’ve lost family members to breast cancer, so I’m very aware about the risks to women, but I don’t know about the risks of prostate cancer, or other cancers that affect men as much.”
Although the overwhelming sentiment was one of sympathy, surprise and sadness at the timing, others were less concerned about the announcement such as Carrie Buchanan, 18, who was bemused by all the attention.
“He’s just got cancer, everybody else gets cancer so why is it a big deal, just because it’s him?”
Charles will be stepping back from public duties during treatment for the disease on the advice of his doctors, according to Buckingham Palace. However, he will continue to oversee state business and official paperwork.
The king is understood to be travelling to Sandringham to rest having begun treatment for the unknown cancer.
Prince Harry touched down in London at lunchtime today and is understood to have met his father for around 45 minutes.
In the statement, the Palace said: “He remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible.”