Buckingham Palace announced on Monday 5 February that Charles has been diagnosed with a form of the disease and will be stepping back from public duties.
The announcement comes after the monarch, 75, underwent surgery for an enlarged prostate last month.
He informed members of the royal family about his diagnosis before the public statement
Charles was last pictured on Sunday 4 February, waving to onlookers as he walked to church on the Sandringham estate in Norfolk.
He appeared in good spirits as he made the short walk to St Mary Magdalene Church, accompanied by Queen Camilla.