AbstractBackgroundWe examined patient‐level factors (patient characteristics, disease and treatment factors, and patient experience), patient‐centered communication (PCCM), and non‐adherence to adjuvant chemotherapy (AC) guidelines among breast and colon cancer patients to inform AC adherence promotion and improve clinical outcomes.MethodsDescriptive statistics for patient‐level factors, PCCM, and AC non‐adherence (primary non‐adherence, non‐persistence at 3 and 6 months) were obtained. Multiple logistic regression models were used to estimate AC non‐adherence after accounting for the identified patient‐level factors.ResultsThe majority of the sample (n= 577) were White (87%), breast cancer patients (87%), and reported PCCM (provider communication score ≥ 90%, 73%, provider communication score = 100%, 58%). All three levels of AC nonadherence were significantly higher in breast cancer patients (69%, 81%, and 89% for primary non‐adherence, and non‐persistence at 3 and 6 months, respectively) than colon cancer patients (43%, 46%, and 62%, respectively). Male sex, survey assistance, and low/average ratings of a personal doctor, specialist, and healthcare were associated with lower PCCM. Older age, breast cancer diagnosis, and diagnosis group following 2007–2009 increased the likelihood of all three levels of AC non‐adherence. Comorbidities and PCCM‐90 were exclusively associated with non‐persistence at 3 months.ConclusionsAdjuvant chemotherapy non‐adherence varied by cancer diagnosis and treatment factors. The relationship between PCCM and AC non‐adherence differed by level of PCCM, time period, and the presence of comorbidities. AC guideline adherence, communication, and value‐concordant treatment should be assessed and compared simultaneously to improve our understanding of their interrelationships.