What is the theme in Refuge: An Unnatural History of Family and Place by Terry Tempest Williams?

Cancer is one of the main topics featured in "Refuge: An Unnatural History of Family and Place." During the course of the book, Williams' mother, Diane Dixon Tempest is stricken with ovarian cancer. Diane is not the first member of the Tempest family to have cancer. In fact, Williams reports that the members of her family, not all related by blood, have all been deeply affected by cancer. At the time of the author's writings, nine members of the Tempest family have succumbed to cancer; seven of the women undergo mastectomies. The latter prompts the final chapter in the book: "The Clan of One-Breasted Women."