Abstract Disclosure: A.M. Sawka: None. S. Ghai: None. L. Rotstein: None. J.C. Irish: None. J.D. Pasternak: None. P.J. Gullane: None. E. Monteiro: None. J. Su: None. W. Xu: None. J.M. Jones: None. A. Gafni: None. N.N. Baxter: None. D.P. Goldstein: None. Background: It is important to understand the fears of individuals newly diagnosed with papillary thyroid cancer (PTC) to optimize patient counselling and supportive care. Our aim was to explore for potential gender differences in fears experienced by individuals with PTC prior to treatment. Methods: In this prospective study conducted in Toronto, Canada, we enrolled patients with untreated small low risk PTC (< 2 cm in maximal diameter), and offered them the choice of thyroidectomy or active surveillance (Clinicaltrials.gov: NCT03271892). All participants had a surgical consultation prior to assessment. Participants completed Fear of Progression (Short Form) and Fear of Surgery (referring to thyroidectomy) questionnaires, prior to making a decision on PTC management. We also evaluated potential fears that were specific to thyroidectomy (e.g. voice change, thyroid hormone treatment, hypocalcemia, and scar appearance). Total fear scores were calculated for the respective questionnaires. We compared data collected in women and men and explored for factors associated with respective fears using multivariable linear regression analyses. Results: We included 153 women of mean age 50.7 years (standard deviation, SD 15.0) and 47 men of mean age 56.3 years (SD 13.8). There were no significant differences in primary tumor size, marital status, education, parental status, or employment status of women and men. On a scale of 5 to 60 (where 60 is the worst), the mean total fear of disease progression questionnaire score was 26.2 (SD 9.7) in women and 23.0 (SD 9.2) in men (p=0.031). On a scale of 0 to 80 (80 being the worst), the mean total surgical fear questionnaire score was 34.1 (SD 20.3) in women and 22.0 (17.9) in men (p<0.001). Women were also more fearful than men about potential postoperative change in voice (p=0.001), hypocalcemia (p=0.003), and scar appearance (p<0.001). In respective multivariable linear regression analyses, age group (p<0.001) was independently inversely associated with fear of disease progression, whereas being a woman was independently associated with surgical fear (p=0.002). Conclusions: Demographic factors appear to be associated with fears of low-risk PTC patients who are considering primary disease management. Younger patients may have a greater fear of disease progression while women may have a greater fear of the morbidity from thyroidectomy. These factors may be important to consider in patient counselling. Presentation: Friday, June 16, 2023