[en] Background: Breast cancer is the most prevalent cancer among adult women. This pathology has negative effect on physical, psychological and emotional quality of life, especially if patients undergo a mastectomy. The identity lost perceived by these women has a significant impact on emotional and psychological well-being, causing them emotional and social distress which usually comes with hypervigilance, anxiety and depression. Objectives: To explore the quality of life and subjective psychological well-being of women with breast cancer after surgical mastectomy in the A Mariña Healthcare District (Lugo, Spain). Material and Methods: We will conduct an observational, descriptive and prospective study. Participants will be recruited at the the Surgery Service of the Public Hospital of A Mariña between January 2021 and December 2024. The inclusion criterial include: (1) women between 18 and 65 years with an anatomical-physiological diagnosis of breast cancer; (2) who are in Stage I and II of breast cancer, and; (3) who voluntarily agree to participate in the study and to sign the informed consent. Participants will be selected consecutively until gathering a sample of 110 women. This sample size allows to assess quality of life and subjective well-being assuming a 95% confidence interval and a maximum margin of sampling error of 2,2 and accounting for a potential participant dropout of 75%. Quality of life will be measured with the Functional Assessment of Cancer Therapy- Breast (FACT-B), while subjective psychological well-being will be addressed with the Spanish Body Image Scale (S-BIS), the Hospital Anxiety and Depression Scale (HADS), the Satisfaction With Life Scale (SWLS), the Subjective Vitality Scale (SVS) and the Rosenberg Self-Esteem Scale (RSE). Analyses will be performed using SPSS 24.0. Bivariate and multivariate linear regression analyses will be carried out in order to assess the objectives of the study.

[gl] Introdución: O cancro de mama é o tumor que presenta maior incidencia en mulleres. Esta patoloxía afecta física, emocional e psicolóxicamente a súa calidade de vida, especialmente tras someterse a unha mastectomía. O benestar emocional e psicolóxico vese afectado principalmente pola perda de identidade a que se someteron, causándolles un desequilibrio emocional e social que pode conducir a un estado de hipervixilancia, agravando así os seus niveis de ansiedade e depresion. Obxetivos: Determinar a calidade de vida e o benestar psicolóxico subxetivo de mulleres con cancro de mama sometidas a unha mastectomía no Distrito Sanitario da Mariña. Material e métodos: Estudo observacional, descriptivo, transversal de carácter prospectivo que se desenvolverá no Servizo de Ciruxía do Hospital Público da Mariña. Terá unha duración de 48 meses, comezando en xaneiro de 2021 e rematando en decembro de 2024. Os criterios de inclusión que se empregarán son: (1) mulleres de entre 18 e 65 anos con diagnóstico anatomofisiolóxico de cancro de mama; (2) que se atopen no Estadío I e II da enfermidade, e; (3) que acepten participar voluntariamente no estudo e firmen o consentimento informado. As pacientes seleccionaranse de xeito consecutivo ata alcanzar unha mostra de 110 participantes, o que permitirá estimar a variable principal, cunha seguridade do 95%, unha precision de ± 2,2 e asumindo unhas pérdas do 25%. Aplicaranse os cuestionarios validados Functional Assessment of Cancer Therapy-Breast (FACT-B) para medir a calidade de vida, o Spanish Body Image Scale (S-BIS), Hospital Anxiety and Depression Scale (HADS), Satisfaction With Life Scale (SWLS), Subjetive Vitality Scale (SVS), Escala de Autoestima de Rosenberg (RSE) para medir o benestar psicolóxico subxetivo. Os resultados analizaranse co programa SPSS 24.0 a través dunha análise estadística bivariante e multivariante de regression lineal e loxística.