<![CDATA[Breast cancer ranks among the most prevalent forms of cancer, with chemotherapy serving as the primary treatment modality. Oral chemotherapy has emerged as a more practical option for patients, making adherence essential to its effectiveness. This study aimed to evaluate adherence to oral chemotherapy among patients with breast cancer. Using a descriptive observational cross-sectional design, the study was conducted among breast cancer patients receiving oral chemotherapy at a regional general hospital in East Kalimantan, Indonesia. Data were collected through the Oral Chemotherapy Adherence Scale (OCAS) questionnaire completed by the patients. A total of 55 female breast cancer patients, mostly aged 46–64 years (70.9%), married (87.3%), and unemployed (69.1%), were studied. Most had been diagnosed for 1–3 years (60.0%) and were in stage III (56.4%). All participants were covered by Indonesian Healthcare Insurance (JKN). The most prescribed oral chemotherapy was Tamoxifen (67.2%), followed by Capecitabine (5.5%), Exemestane (2.5%), and Letrozole (1.8%). Overall, 80% of patients demonstrated good medication adherence, with high compliance (94.5%) and persistence despite side effects (99%). Common barriers included forgetfulness (23.6% occasionally; 27.2% rarely) and difficulties accessing healthcare (70.9%). Most patients followed proper drug administration practices. Tamoxifen is the most commonly prescribed oral chemotherapy for breast cancer. This study shows that breast cancer patients generally adhere well to their oral chemotherapy regimens, though a minority may still struggle with adherence.]]>
