Cancer information overload may be a crucial determinant of adjuvant aromatase inhibitor adherence.

Medication non-adherence is the leading preventable cause of death among cancer patients. We aimed at investigating whether an online search on cancer treatments creates information overload and to determine the effect of online search on treatment adherence in postmenopausal breast cancer (BC) patients receiving adjuvant aromatase inhibitor (AI) treatment.A total of 103 patients completed the demographic and medical information form, Cancer Information Overload (CIO) scale, Hospital Anxiety Depression Scale (HADS), and Modified Medication Adherence Questionnaire (MAQ).More than half of the patients (n=55, 53.4%) performed an additional online search on BC treatment. Median HADS-Anxiety scores, HADS-Depression scores, CIO scores, and percentage of patients with a low MAQ status were 10.00 (7.00-13.00) and 4.00 (3.00-6.75) (p<0.001), 11.00 (6.00-14.00) and 4.00 (2.00-6.00) (p<0.001), 24.00 (17.00-28.00) and 12.00 (10.00-15.00) (p<0.001), and 63.6% (n=35) and 39.6% (n=19) (p=0.018) for the searcher and non-searcher groups, respectively. Co-morbidity(s) (OR 2.407, 95% CI 1.017-5.700, p=0.046) and CIO score (OR 1.126, 95% CI 1.006-1.259, p=0.039) were independent predictive factors of a low MAQ score.CIO is one of the main determinants of non-adherence to adjuvant AI treatment. An additional online search on cancer treatment may negatively contribute to patients' CIO, depression, and anxiety levels and does not seem to be beneficial for treatment adherence.