Within hours, the patients’ forearms grew red and swollen. Five to ten days later, hard nodules began growing at the injection sites. Southam removed some of the nodules to verify that they were cancerous, but he left several to see if the patients’ immune systems would reject them or the cancer would spread. Within two weeks, some of the nodules had grown to two centimeters—about the size of Henrietta’s tumor when she went in for her radium treatments.
