Objective: Young breast cancer patients experience greater psychosocial distress compared with older patients, which raises concern for their risk of posttraumatic stress disorder (PTSD). We sought to characterize the prevalence of clinically significant symptoms of PTSD and associated factors among breast cancer survivors diagnosed at a young age. Methods: The Young Women's Breast Cancer Study, an ongoing prospective cohort study, enrolled 1302 women diagnosed with breast cancer at age ≤ 40 between 2006 and 2016. Participants complete serial surveys, and we obtained additional information from medical record review. Socio-demographics, anxiety and depression, social support, and psychiatric co-morbidities and medications were assessed at study baseline (median, 5 months post-diagnosis). We defined a participant as having clinically significant posttraumatic stress symptoms (PTSS) by scoring ≥50 on the PTSD Checklist-Specific Version, administered on the 30-month survey. Results: Among 700 women with stage 1-3 disease, the prevalence of PTSS was 6.3% (95%CI = 4.5-8.1). In multivariable analyses, PTSS was significantly associated with anxiety (OR 12.43, 95%CI = 5.81-26.59, P < .0001) and stage 2 vs 1 disease (OR 2.26, 95%CI = 1.04-4.93, P = .04). PTSS was inversely associated with having a college degree (OR 0.29, 95%CI = 0.13-0.62, P = .002) and greater social support (OR 0.44, 95%CI = 0.21-0.94, P = .03). Conclusions: We found similar rates of cancer-related PTSS in breast cancer survivors diagnosed at a young age compared with the general breast cancer population despite their well-documented increased risk of overall distress. Nevertheless, factors associated with posttraumatic stress should be considered at diagnosis and in survivorship to identify young patients who may benefit from psychosocial resources.

202 Background: Posttraumatic stress disorder (PTSD) is associated with morbidity and mortality in affected populations. Cancer survivors experience PTSD at a rate higher than the general population, with young age and female gender identified as risk factors. While young women with breast cancer experience greater psychosocial distress in general following diagnosis (dx), little is known about PTSD in this population. Methods: Women dx’d with Stage I-III breast cancer at age ≤ 40 were surveyed as a part of a multi-site cohort study. Demographic, treatment, psychosocial characteristics (including self-reported psychiatric conditions and use of psychiatric medications prior to dx), anxiety and depression (Hospital Anxiety and Depression Scale), fear of recurrence (Lasry Scale), and social support (Medical Outcomes Study) were assessed within 1 year after dx. PTSD was measured at 30 months post-dx using the PTSD Checklist – Civilian Version; a score ≥ 50 was considered positive for PTSD. Univariable and stepwise multivariable logistic regression were used to evaluate factors associated with PTSD. Results: 572 women were eligible for this analysis; median age at dx was 37 (range: 17-40); 87% had Stage I or II cancer. 37/572 women (6.5%) met criteria for PTSD at 30 months. Lower educational attainment, less financial comfort, less social support, stage 2 (vs. 1) disease, receipt of chemotherapy, fear of recurrence, anxiety and depression, and psychiatric comorbidities were associated (p ≤ 0.05) with PTSD in univariable analyses. Chemotherapy (OR = 3.48, 95% CI = 1.09-11.06), anxiety by HADS (OR = 20.29, 95% CI = 7.83-52.53), and psychiatric comorbidities (OR = 4.22, 95% CI = 1.40-12.74) were associated with increased likelihood of PTSD, whereas college education (OR = 0.25, 95% CI = 0.10-0.59) and greater social support (OR = 0.41, 95% CI = 0.17-0.99) appeared to be protective in multivariable analyses. Conclusions: PTSD affects a minority of young breast cancer survivors, with the prevalence in our cohort similar to that seen in other breast cancer populations. Early identification of those at risk for developing PTSD is essential for the adequate treatment of affected women and for the improvement of health outcomes and quality of life in cancer survivors.