William has not been seen in public since the announcement and is not expected to return to full-time duties until their children go back to school.
Speaking on camera to share her diagnosis, Kate said that she and her husband had been “doing everything we can to process and manage this privately for the sake of our young family”.
Having William alongside her had been “a great source of comfort and reassurance”, she added, as she continues to “focus on making a full recovery”.
In the emotional message, the Princess of Wales said it had been an “incredibly tough couple of months” for her and her family, but that she was “getting stronger every day”.
“My work has always brought me a deep sense of joy and I look forward to being back when I am able, but for now I must focus on making a full recovery,” she continued.
Kate last appeared in an official capacity at the Christmas Day service in Sandringham last year, and as of yet there is no set date for her return to public life.
Prince William, Kate Middleton and their three children have kept a low profile since the Princess of Wales announced her diagnosis. Photo / Getty Images
The news came after weeks of theories about her whereabouts and wellbeing circulating online.
A former Palace aide told People magazine that the concern about her health was a “complex reaction”.
“There was no malintent,” they said. “But it unleashed a pent-up feeling that people wanted information - unfortunately, that’s the curse of being a modern royal.”
King Charles has also been diagnosed with cancer after undergoing prostate surgery in January.
