Age-Related Clinicopathologic Features And Survival In Papillary Serous Uterine Cancer Patients Older And Younger Than 70: An Exploratory Analysis Of A Series Of Consecutive Patients.

e18104 Background: Papillary serous uterine cancer (PSUC) is a rare, clinically aggressive histotype accounting for 40% of uterine cancer deaths. Clinicopathologic characteristics and outcomes between older and younger PSUC patients may differ. Methods: With IRB approval, we conducted a retrospective analysis of 554 consecutive patients with uterine cancer treated at our institution from 2009-19. Consistent with findings from the SEER database, 28 patients (5%) had PSUC. Most PSUC patients were Caucasian; Latinas comprised 14.2%. Thirteen patients were seventy years of age or younger (≤70) and fifteen were older than seventy ( > 70). Clinicopathologic features, therapy and survival were compared between two cohorts. Statistical analysis: Significance of associations was assessed with Fishers' exact test. Survival analysis was performed with Cox proportional model with censoring to calculate hazard ratios (HR). Results: The two cohorts were well-balanced for stage (TNM stages I+II vs. TNM stages III+IV). More than 90% of patients in each group had surgical excision/debulking, and nearly half of patients in each group received systemic chemotherapy. The most frequently used chemotherapy regimen was carboplatin-paclitaxel. Compared to patients ≤70, patients > 70 were less likely to undergo postoperative radiation therapy (6% vs 61.5%; p = 0.001). Cancer-specific survival (CSS) was worse in patients > 70 as opposed to patients ≤70 (21.8 vs. 27.4 months; HR 0.61, p = 0.03). Four PSUC patients > 70 had a personal history of metachronous breast cancer; none ≤70 had a history of breast cancer. We identified five cases of breast cancer, two cases of colon cancer, and one case each of ovarian and uterine cancer in first-degree relatives of PSUC patients > 70. Conclusions: Older PSUC patients displayed significantly shorter CSS than their younger counterparts. They were also less likely to receive radiation therapy. As personal and family history of older PCUS patients identified an excess of other cancers, comprehensive germline mutation testing may be warranted. Final statistical analysis, comparison to SEER data and significance will be presented.