 Hereditary non-polyposis colorectal cancer HNPCC is associated with up to an 80 lifetime risk of developing colorectal cancer and a 40-50 chance of a metachronous tumor after partial colectomy for the disease. For these patients, prophylactic colectomy has been proposed as a potential risk management alternative to a lifetime of intensive surveillance by colonoscopy. The highly personal nature of such risk management decisions has been recognized in the development of individualized genetic counseling services. However, prior psychosocial research in this area has tended to use linear statistical techniques in which clinically important details are lost in an overly broad, one size-fits-all model that is difficult to apply in a one-to-one counseling session. We propose an innovative approach based on the Cognitive-Social Health Information Processing C-SHIP model in which we will explore how attitudes towards prophylactic colectomy are organized into meaningful patterns or types that can translate readily into tailored counseling recommendations. Specific aims of this study are: 1to assess levels of intention in prophylactic colectomy among HNPCC patients; 2To identify distinctive decision types based on profiles of perceived pros and cons of prophylactic colectomy; and 3 To explore the pattern of relations between decision types and counseling-related outcomes level of intention in colectomy, cancer-specific anxiety, and colonoscopy adherence. We will conduct a one-time cross-sectional telephone survey of 320 HNPCC patients defined as either carriers of a mutated mismatch repair gene associated with HNPCC or those with a personalfamily history meeting published criteria for HNPCC. Using cluster analysis we will create a taxonomy of decision types. Prior research leads us to expect at least three types: Disengaged, Risk-Focused, and Ambivalent. We hypothesize that each type will have a different pattern of relations with the outcome variables e.g., Risk-focused types will show higher level of intention regarding surgery, high anxiety, low avoidance, and high colonoscopy adherence, whereas Ambivalent types will show higher level of intention regarding surgery, high anxiety, high avoidance, and low colonoscopy adherence. Understanding these patterns will enhance the ability of physicians, genetic counselors, and other providers to help their patients make well informed, thoughtful decisions about the preventive strategy that will best protect their health, emotional well-being, and quality of life. 