Health-Related Quality of Life by 31-item Cervantes Scale in Breast Cancer Survivors Undergoing Adjuvant Endocrine Therapy

Introduction: Instruments to manage adverse effects of endocrine therapy with Aromatase inhibitors (AI) may improve adherence and persistence to treatment and Health-Related Quality of Life (HRQL). The 31-item Cervantes Scale (CS-31) is an HRQL questionnaire with particularities of the perimenopausal and postmenopausal period that could be an appropriate instrument to assess HRQL in Breast Cancer (BC) survivors.

Objective: This study aimed to perform additional validation of the CS-31 for BC survivors undergoing adjuvant endocrine therapy.

Methods: This prospective study was performed at three time points named T0, T1, and T2: initial, intermediate, and final follow-up period, respectively, totaling 24 months of follow-up. At each time point, the participants completed the CS-31, Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F), and Hospital Anxiety and Depression Scale (HADS). The internal consistency, construct validity, responsiveness analyses, and known-group validity of CS-31 were evaluated.

Results: This study included 89 postmenopausal women diagnosed with hormone receptor-positive early BC in adjuvant endocrine therapy with AI. The internal consistency was good (Cronbach's alpha = 0.89). Construct validity received a positive rating, with 100% of results consistent with prior hypotheses. A prospective improvement in HRQL was identified for the CS-31 Global Score and FACIT-F Total Score and for most of their domains. Furthermore, women with anxiety and depression by HADS presented worse HRQL by CS-31.

Conclusion: The authors identified that the CS-31 seems to be appropriate for use in oncology medical routine and may help to monitor adverse effects and HRQL of BC survivors during adjuvant endocrine therapy.