BACKGROUNDLittle is known about how disparities in the treatment of patients with breast carcinoma based on patient age and ethnicity are effected or mitigated at the patient‐physician interaction level. The objectives of this study were to document physician provision of informational support to patients at the time of a new diagnosis of breast carcinoma and to assess differences according to patient age and ethnic group in terms of the information received and desired.METHODSParticipants were 222 patients with breast carcinoma in Los Angeles County, California, age ≥ 55 years who were interviewed within 6 months of their diagnosis of breast carcinoma and/or within 1 month posttreatment. Respondents were asked about receipt and helpfulness of 10 tangible informational support items (e.g., whether booklets, videotapes, medical records, etc. were provided by physicians) and 15 interactive informational support items (e.g., whether physicians discussed breast cancer topics, such as risk of recurrence or treatment options). An index of the tangible informational support items and a scale of the interactive informational support items received were created for summary analyses. Patients' medical records were abstracted for breast carcinoma stage and treatment type; surgeons also were surveyed about sociodemographic and practice characteristics.RESULTSIn multiple linear regression analyses, older age (β coefficient [β] ± standard error [SE], − 0.08 ± 0.02; P = 0.001) and Latina ethnicity (β ± SE, − 1.21 ± 0.40; P = 0.003) had a negative association with physician provision of interactive informational support, controlling for patient and physician sociodemographic characteristics, practice characteristics, breast carcinoma stage, comorbidity, number of physicians seen, visit length, social support, and patient self‐efficacy in interacting with physicians (adjusted correlation coefficient [R2] for the model, 0.33; P < 0.00001). Both older patients and ethnic minority patients, as well as their respective comparison groups, rated most breast cancer information as at least as helpful. Both groups preferred interpersonal sources of information to written sources, although they received interpersonal sources less frequently.CONCLUSIONSOlder patients and Latina patients with breast carcinoma received less interactive informational support from their physicians compared with younger patients, differences that persisted after controlling for a wide range of sociodemographic, psychosocial, and physician factors. Improving the quality of communication at the patient‐physician interaction level may be an important avenue to reducing age and ethnic group treatment disparities among patients with breast carcinoma. Cancer 2003;97:1517–27. © 2003 American Cancer Society.DOI 10.1002/cncr.11211