RT Journal Article SR Electronic T1 EP1027 Ovarian cancer with and without other primary cancers – are these different entities? JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A541 OP A541 DO 10.1136/ijgc-2019-ESGO.1071 VO 29 IS Suppl 4 A1 L Wong A1 TH Lao A1 HS Lee A1 SF Yim A1 SY Yeung YR 2019 UL http://ijgc.bmj.com/content/29/Suppl_4/A541.1.abstract AB Introduction/Background Multiple primary cancers (MPC) refer to more than one cancer in the same or different organs being diagnosed in the same patient, which are uncommon. But as the population ages, the growing number of cases of multiple primary cancer becomes an increasingly important medical issue. The purpose of this study was to evaluate the clinic-pathological characteristics of ovarian cancer patients who had multiple primary cancers.Methodology In a retrospective study, we reviewed 534 patients presenting with primary ovarian cancer between January 1, 2006, and December 31, 2017. Patients were divided into those with primary ovarian cancer only and those who had in addition other primary cancers for comparison of patient characteristics and presentation, including the staging and histological types, and short term (two-years) mortality from ovarian cancer.Results 17.0% (91/534) of patients with ovarian cancer had multiple primary cancers. The most common other malignancies were endometrial cancer (57.1%), followed by breast cancer (27.5%) (table 1). Patients with multiple primary cancers presented at earlier stages for the ovarian cancer at FIGO stage 1 or 2 (OR 1.217, 95% CI 1.034–1.432), they had more epithelial than other histological types of ovarian cancer (OR 1.076, 95% CI 1.039–1.115), with more being nulliparous (OR 1.336, 95% CI 1.034–1.727) and having family history of malignancies (OR 1.866, 95% CI 1.221–2.853). There was no significant difference in the disease-free survival up to 24 months (OR 1.098, 95% CI 0.966–1.248) (table 2).View this table:Abstract EP1027 Table 1 Frequency of other primary cancers in patients diagnosed with ovarian cancer and multiple primary cancersView this table:Abstract EP1027 Table 2 Patient characteristics between those with ovarian cancer with and without multiple primary cancersConclusion The finding of this study suggested that patients with multiple primary cancers have different characteristics which may represent different entities, but without apparent prognostic implications.Disclosure Nothing to disclose.