Kate Middleton and Prince William Have 'Intense Anxiety' About King Charles' Cancer Diagnosis

King Charles and Kate Middleton are battling cancer at the same time, and royal expert Tina Brown believes His Majesty's condition is making the Princess of Wales and Prince William think more about their future as royals.

"News of Charles’ cancer has put William and Catherine in frightening proximity to ascending the throne...The prospect of it, I am told, is causing them intense anxiety," Brown wrote in an article.

As Charles and Kate focus on their health, William and Queen Camilla continue to be the forward-facing leaders of The Crown.

Despite Charles taking a step back from public life, he was able to attend the royal Easter service.

"The King is raring to go after a significant amount of time off due to his cancer diagnosis," an insider told a publication. "He knows he can't hang around and is feeling extremely positive after tests meant he could attend the Easter Sunday service and spend time meeting the public, which he has missed."

"He's over the moon with the way treatment has gone and supercharging plans for Australia, New Zealand and Samoa," they added, referring to his upcoming travel plans.

On Friday, March 22, Kate returned to Instagram to update fans on her health after she was noticeably missing from the spotlight.

"I wanted to take this opportunity to say thank you personally for all the wonderful messages of support and understanding whilst I've been recovering from surgery," Kate began in an Instagram video. "It has been an incredibly tough couple of months for our entire family. In January, I underwent major abdominal surgery in London. At the time, it was thought that my condition was non-cancerous. The surgery was successful, however, tests after the operation found cancer had been present. My medical team therefore advised I should undergo preventive chemotherapy, and I am now in the early stages of that treatment."

The Princess of Wales continued: "This of course comes as a huge shock, and William and I have been doing everything we can to process and manage this for our young family. It has taken my time for me to recover from my surgery. Most importantly, it has taken us time to explain to George, Charlotte and Louis and to reassure them I am going to be OK. As I've said to them, I am well. Having William by my side is a great source of comfort, and the love and support and kindness that has been shown from so many of you. As a family, we need some time, space and privacy while I complete my treatment. My work has always brought me a deep sense of joy. I must focus on making a full recovery. At this time, I am also thinking of those whose lives have been affected by cancer. Please do not lose faith or hope. You are not alone."

OK! previously reported Charles met with his daughter-in-law after she came forward about her diagnosis.

"It is highly unusual for just the two of them to sit down together like this," a source told an outlet. "The King had already been made aware that the woman he calls 'my beloved daughter-in-law' had cancer."

"They would have had lots to discuss and share because just weeks earlier the King had begun his course of treatment and dealt with announcing his diagnosis," they added.

Brown wrote for The New York Times.

Insiders spoke to The Sun.