Breast cancer (BCa) is the leading cause of mortality in Hispanic women and the most commonly diagnosed cancer in this minority group, the largest and fastest growing ethnic group in the US. Compared with other racial/ethnic groups, Hispanic women have a higher rate of discontinuation of adjuvant hormone therapy (AHT) treatment. This finding is particularly relevant because the gap between Hispanic and NHW women in BCa survival is known to be largest among estrogen-sensitive subtypes in whom prolonged AHT treatment over years is key to improving outcomes. Because nonadherence has been shown to affect survival outcomes and increase mortality, differential utilization of AHT may contribute in part to the disparities in Hispanic BCa outcomes. Guided by our team's Cognitive-Social Health Information Processing Model and health communication best practices, an evidence-based mobile text messaging intervention (Txt2Adhere), designed to promote adherence to AHT, was iteratively developed with patient-centered input and clinical and behavioral evaluation during year 1 of the Parent Grant. The proposed supplement research study is a logical extension of this line of research in the area of adherence promotion to anticancer oral treatment, while at the same time adding Dr. Clara Granda-Cameron's (the supplement grant candidate) expertise by providing training in the intersection of BCa health disparities and mHealth research, and adapting a theory-guided and carefully-tested intervention prototype of use with an underserved segment of BCa population. We will first examine Hispanic BCa survivors' perceived barriers and facilitators on adherence to AHT through a qualitative study. Guided by a Hispanic community advisory board and the qualitative findings, we will adapt the Parent Grant intervention “Txt2Adhere” to a linguistically-appropriate and culturally-informed intervention (MeCuido) for Hispanic BCa survivors through a 3-stage cultural adaptation and formative evaluation process. Three priority training areas, 1) qualitative and quantitative research methodologies, 2) health disparities in minority populations, and 3) mHealth and health communication, are identified to enhance Dr. Granda-Cameron's understanding of the methodologies and results of the proposed supplement study. Training will be implemented through formal coursework, local and national workshops, seminars and training institutes, as well as continuous interaction with mentors and advisors with relevant expertise. Dr. Kuang-Yi Wen (PI of the Parent Grant) and Dr. Ana Maria Lopez will provide their mentorship and guidance to 1) facilitate the progression of Dr. Granda- Cameron's training activities, 2) guide the implementation of the proposed supplement research project, and 3) promote Dr. Granda-Cameron's transition to an independent investigator. This study is significant because MeCuido has the potential to reduce disparities in AHT adherence among Hispanic BCa women and will provide Dr...