I’m doing it because I love you,’ " the father of one told the outletPrincess Kate announced her cancer diagnosis in March 2024 before confirming she was in remission in January of this yearJames Middleton is opening up about his older sister Kate Middleton's cancer diagnosis. Kate Middleton With Younger Brother James Arrive At The Concert For Diana At Wembley Stadium, 2007. Middleton said Princess Kate and their sister, Pippa Middleton, 41, had even accompanied him to a couple of therapy sessions. Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! My love and support for my family is more than just an Instagram post,” referencing his March social media post about the diagnosis.