“It’s probably nothing. You’re so young and healthy.” When Liz Acosta felt a lump in her breast, that’s what she—and her friends and family—thought. But Liz, who is in her early 30s, went to the doctor anyway. And she left with a breast cancer diagnosis. The next day, the San Francisco resident was on an exam table at the hospital when the reality hit her. “I remember lying there and I started crying and thinking, ‘I don’t want to lose my hair,’” she said. So many hairdressers have experienced cancer, whether it’s their clients, family...