UK’s King Charles’ cancer was caught early and the whole country is hoping he can make a full recovery, British Prime Minister Rishi Sunak said on Tuesday, as messages of support for the 75-year-old monarch poured in from world leaders.

Buckingham Palace revealed on Monday that Charles, on the throne for less than 18 months since the death of his mother Queen Elizabeth, was suffering from a “form of cancer” and would postpone his public engagements to undergo treatment.

The king was remaining “wholly positive” and looking forward to returning to public work as soon as possible, the palace said.

Charles’ younger son Prince Harry, estranged from the royal family, is due to arrive in Britain shortly and his elder brother, heir-to-the-throne Prince William, is expected to step up to fulfil some of the monarch’s duties.

Sunak said he had been “shocked and sad” at the news.

“All our thoughts are with him and his family. You know, thankfully, this has been caught early,” he told BBC radio.

Charles is planning to continue with much of his private work as monarch including his weekly audience with the prime minister and dealing with state papers, and Sunak said he was in regular contact with the king.

“That will of course continue as normal and we’ll crack on with everything,” he said.

Charles spent the night at his Clarence House home near Buckingham Palace on Monday after beginning a series of out-patient treatments.

The cancer was discovered when Charles spent three nights in hospital last month where he underwent a corrective procedure for a benign enlarged prostate. Beyond confirming it was not prostate cancer, the palace has not given any further details.

The royal family usually keep medical matters private, but the palace said Charles had chosen to go public as he was patron of a number of cancer-related charities.

While the king will receive expert care, his diagnosis will draw attention to Britain’s rising cancer waiting times with the state-run National Health Service (NHS) which is widely regarded as being in crisis.

Survival rates for cancer in Britain lag those of other European countries for nine out of 10 of the most common types of the disease, according to an NHS Confederation report published in January.

Surprise diagnosis

The surprise diagnosis has dominated British media since the announcement was made, and is the another personal blow for Charles during his year and a half on the throne.

Early last year, Harry published his autobiography “Spare”, which contained damning revelations about his father and elder brother, while Charles has also had to contend with ongoing allegations against his brother Prince Andrew relating to the late sex offender Jeffrey Epstein.

Harry, who quit royal duties in 2020, is flying back to Britain from California where he lives with his American wife Meghan and two children after Charles told him and his other immediate family of his diagnosis.

The king’s cancer revelation comes as Kate, the Princess of Wales and wife of heir William, recuperates at home after spending two weeks in hospital following planned abdominal surgery for an unspecified but non-cancerous condition.

She is not expected to return to public duties until after Easter and the absence of the senior figures will put pressure on the other working royals to perform extra engagements.

Charles has always been keen to have a more slimmed down monarchy but with his younger brother Andrew and Harry no longer involved, all those who currently carry out royal engagements are aged over 50 apart from William and Kate, with some now in their 80s.

His sister, Princess Anne, often tops the list for being the busiest royal, followed by Charles.

“After the upheavals caused by the death of the late Queen and the controversies surrounding the Dukes of Sussex and York (Harry and Andrew), the hopes after the Coronation were for a period of calm and consolidation,” the Daily Telegraph said in an editorial.

“But illnesses cannot be predicted or avoided, not even by a man who has looked after himself so well. We, along with the rest of the nation, wish His Majesty a speedy recovery.”