The Princess of Wales offered comfort to cancer patients and their families as she made an emotional return to the hospital where she was treated, telling them: “There is light at the end of that tunnel.†Kate spoke candidly about her own diagnosis, the “shock†of her “really tough†chemotherapy and the challenges of getting back to normal as she visited the Royal Marsden Hospital in Chelsea, south-west London, on Tuesday to thank her “amazing†medical teams for her care. The princess, on her first major solo official engagement for more than a year, hugged Tina Adumou, who broke down in tears as she told Kate that her 19-year-old daughter is in the intensive care unit.