The Queen is “very knowledgeable” about the impact cancer can have on families, an expert has said.

Camilla has been president of Maggie’s cancer charity for the last 15 years and regularly meets patients during visits to its centres.

Maggie’s chief executive Dame Laura Lee said the 76-year-old Queen is very “compassionate and empathic” about supporting a person with cancer and their family.

The Queen is very knowledgeable about the impact of cancer and is very compassionate and empathic in terms of understanding the impact and role of support that she will undoubtedly be offering the King during this time

She also praised the King for helping cancer patients understand that they are “not alone” and that “he is with them”.

Camilla launched a Maggie’s centre at the Royal Free Hospital in London last week – before the King’s diagnosis was announced.

Dame Laura told BBC Breakfast: “As ever, the Queen was in good and strong spirits.

“She has been in and visited many of our Maggie’s centres and so it was a day of work for her, of coming and helping us celebrate and open the centre.

“So, obviously, we know this information about King Charles after that visit, but during it she sat down, as she does in all of our centres, with a group of people affected by cancer, who talked about their own stories, about how they had navigated the challenges of cancer, and how important support was for them.

“So the Queen is very knowledgeable about the impact of cancer and is very compassionate and empathic in terms of understanding the impact and role of support that she will undoubtedly be offering the King during this time.”

She added: “She has been our president for the last 15 years.

“I think she understands that cancer is a very specific experience for each individual, but that it’s also the family that are going through it.

“So she will be thinking about how best to support the King, but she will also be thinking about the rest of the family – Prince William – and also about supporting the King in his wishes to keep fully active and working through treatment.”

Dame Laura said a cancer diagnosis can be a “process of adjustment”, adding: “We’ve all been feeling the shock of hearing this news and that’s the same for any family.

“And then it’s adjusting to: what are the treatment options? What are the paths ahead? What are some of the decisions that I need to make? How will that affect my daily life? How can I keep my work going forward?

“And it is allowing time for everyone to start to adjust to that news and to understand what’s ahead, and it’s as important for the person with cancer as well as the family members.

“And I think what we can see that’s happening here is the King has done a wonderful job of telling us about his cancer diagnosis.

“So he’s telling others that he’s going through this, that they are not alone. He is with them on that.

“But he’s also giving his time to his family to come to terms with what’s going on and to what might lie ahead.”

Camilla has been president of Maggie’s since 2008. The charity supports cancer patients and their families, with its 24 centres all based in hospital grounds.

The charity was founded by Maggie Keswick Jencks, and her husband, Charles Jencks, after she received a second cancer diagnosis in 1993 and was moved to a windowless corridor with her partner to process the news.

The couple discussed the need for somewhere better for people with cancer to go, and the first centre opened in 1996 in Edinburgh.