Background: The number of breast cancer survivors is increasing due to improvements in care and an aging population, leading to an increased need for care that addresses the physical and psychological needs of patients after completion of active treatment. The Sunnybrook Breast Cancer Survivorship Program was established to provide comprehensive evidence-based survivorship care and facilitate the transition to family doctors. Despite rising interest in dedicated survivorship care, there is little consensus regarding which individuals are likely to suffer the most long-term impacts of breast cancer treatment. Factors as varied as age, ethnicity, socioeconomic status, and treatment type can influence Quality-of-Life (QoL) outcomes. This cross-sectional assessment uses mixed methods to evaluate QoL trends in the patient cohort. Methods: Current patients of the Sunnybrook Breast Cancer Survivorship Program were asked to complete a baseline information form, as well as the EORTC QLQ-30 and BR-45, two validated measures of QoL for breast cancer patients and survivors. QoL, functional, and symptom domains were calculated from these responses accordingly and analyzed statistically. Patients reported their most bothersome QoL concerns through an open-ended questionnaire, which was analyzed and organized thematically. 99 patients have been recruited to date, of a planned 200. Results: We find that sexual health is of importance for this population, with 50 (50.5%) participants reporting sexual activity. Patients under 50 have poorer sexual functioning scores (p<0.01) as well as more issues with body image (p<0.05) than older survivors. Both married and under-50 patients are significantly more likely to have poorer outlooks on the future (p<0.05; p<0.01). Younger patients also tended to have worse role functioning, cognitive functioning, emotional functioning, and social functioning scores, though these differences were not statistically significant. Thematic analysis of qualitative data showed that patients’ chief concerns were the impact that ongoing side effects had on their daily functioning, impact of treatment on body image, disruptions to work and personal relationships, and strong anxiety about potential recurrence. Conclusions: While it is understood that younger BC survivors face unique challenges, our findings indicate that these obstacles persist into older age groups. In addition to physical side effects, such concerns as body image issues, social strain, and emotional functioning can drive QoL scores for these patients. Notably, many patients endorsed strong anxiety regarding potential recurrence that affected QoL, and identified dedicated survivorship follow-up as an ameliorating factor. Further research should be conducted into the unique needs of under-50 survivors, as well as the role of recurrence anxiety in impacting QoL.