• Thierry Roge / Reuters

    Marie, left, and Gabrielle Vaudremer, 100-year-old twins, cut a cake as they celebrate their birthday at the Chateau Sous-Bois retirement home in Spa, Belgium, Oct. 2. Marie and Gabrielle were born in 1910 and are the world's oldest pair of twin sisters, according to the Guinness World Records.

    A century of sisterhood

    Many people who grow to be exceptionally elderly seem to lose so many of their friends and family. It must be comforting for these sisters to share their 100th birthday.