The chemotherapy made Andrea lose her hair and confidence.
"I would have never imagined being able to go out in public without a wig," she wrote on Instagram. "I had lost most confidence in myself."
Andrea then connected with photographer Gerardo Garmendia, who helped the teen gain back the confidence she had lost.
"This journey has taught me to love and accept myself regardless of the way I look," Andrea wrote. "I've learned that the hair on someone's head doesn't define who they are as a person, but their actions and the way they treat others."
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