The clinical skills required to diagnose breast cancer and to treat patients with this disease are many and varied. The management of breast cancer patients increasingly requires the input of many oncologic specialists, and growing pressure is being placed on primary care disciplines to assume greater responsibility for breast cancer diagnosis and assessment. In the light of studies at our institution demonstrating multiple deficits in critical clinical skills on the part of students and surgery residents, the Structured Clinical Instruction Module (SCIM) has been piloted as a format for enhancing the teaching of clinical skills pertinent to the diagnosis of breast disease and the multidisciplinary care of the patient with breast cancer. The SCIM is an abbreviated course that places trainees in realistic clinical settings, including the opportunity to interact with actual patients. The current study proposes to develop and implement multidisciplinary breast cancer SCIMs through a consortium of breast cancer education working groups at five institutions. The curriculum will encompass all aspects of breast cancer patient assessment, including history and physical examination, risk-factor assessment, attention to psychosocial and interpersonal factors, explanation of treatment options and patient counselling, basic tumor imaging studies, key cytologic and pathologic techniques, and assessment for protocol enrollment. Instruction will be given by experts in the various fields (surgical oncology, medical oncology, radiology, radiation oncology, plastic oncology, plastic surgery, pathology, nursing oncology, and behavioral science) involved in the care of breast cancer patients. The goals of the study are threefold: 1) to establish the SCIM as a comprehensive and portable instructional format that can be used as a training vehicle not only in key specialty disciplines such as general surgery and medical oncology but also in primary care disciplines including nursing, family practice,general internal medicine, and obstetrics and gynecology; 2) to use the SCIM format to assess objectively the clinical competence of nurse practitioners and resident physicians and to identify performance deficits that will allow instruction to be tailored to specific training needs; and 3) to use the objective structured clinical examination to evaluate the short- and long-term effectiveness of the SCIM in improving the clinical skills of nurse practitioners and resident physicians.