LONDON, United Kingdom (AFP) — Crowds of well-wishers on Tuesday greeted King Charles III as he made his first official public appearance since being diagnosed with cancer, after doctors said they were “very encouraged” by the progress of his treatment.

The British head of state and his wife, Queen Camilla, toured the University College Hospital Macmillan Cancer Centre in central London, which diagnoses and treats a wide range of cancers.

Charles, 75, is patron of Cancer Research UK and Macmillan Cancer Support, while Camilla, 76, is president of Maggie’s, another cancer support charity.

The couple smiled and waved to crowds before heading inside to meet medical specialists, patients and their families.

Charles suspended most duties in February after cancer was found while he was being treated for an enlarged prostate the previous month.

The exact nature of his cancer has not been disclosed.

His daughter-in-law Catherine, Princess of Wales, 42, underwent abdominal surgery in January and said in March that she was receiving chemotherapy.

Again, no details were given about what type of cancer she has. Kate, as she is widely known, is married to Charles’s elder son and heir Prince William.