ObjectivesWe aimed to characterize the relationships between breast cancer patient mood symptom severity and demographic/medical factors with clinical communication about mood, and to explore mood discussion content. Methods134 breast cancer patients (mean age=58.3; 14% minority; 13% metastatic) had oncology clinic visits audio-recorded, transcribed, and coded for mood communication. Patient Care Monitor assessed mood symptoms (anxiety/depression presence/severity). Logistic regressions measured associations between mood, demographic/medical factors, and communication. Thematic analysis characterized discussion topics. ResultsOver half of patients (55%; n = 73) reported mood symptoms. Worse mood symptoms were associated with younger age and current treatment (p’s < 0.05). 19% of clinic visits (n = 26/134) contained mood discussions. Discussions were more common for younger women and those with non-metastatic disease (p’s < 0.05). Odds of discussing mood increased with symptom severity (OR=4.52, p = 0.018). Cancer-related anxiety and medication management were among the most common topics discussed. ConclusionsCommunication about mood occurred infrequently, with women currently undergoing treatment, with metastatic disease, or with mild mood symptoms at potentially increased risk for inadequate discussion. Both patient-focused and provider-focused interventions to improve clinical communication about mood symptoms could be beneficial. Practice implicationsClinicians hold a key role in supporting cancer patients’ well-being by using and encouraging effective communication about patients’ mood.