Misdiagnosed and over- or undertreated? Patients with synchronous ovarian and uterine cancers outperform those with single primaries (493)

Objectives: The objectives of this epidemiologic study were to investigate potential misdiagnosis of synchronous endometrial and ovarian cancers, utilizing the Surveillance Epidemiology and End Results (SEER) Program, which is a population-based tumor registry. We hypothesize that women diagnosed with synchronous tumors may have worse overall survival than those with nonsynchronous stage I tumors, closer to stage IIIA endometrial cancer due to misdiagnosis and potential undertreatment. Methods: This retrospective observational study utilized the SEER database to compare synchronous uterine and ovarian cancers cases to those of separate, primary endometrial and ovarian cancers. Kaplan-Meier analyses were used to construct overall survival curves, which were compared with log-rank tests. Cox proportional hazard regression models were utilized to adjust for age, adjuvant treatments, and histologic and grade subgroup pairings. Magnitudes of statistical significance were expressed with age-adjusted HR and 95% CI. Results: Women with stage I synchronous tumors had the highest progression-free survival of all groups compared to stage I non-syn- chronous (NS) ovarian and uterine cancers and NS stage IIIA uterine cancers with an HR of 0.44. The mean age at diagnosis for synchronous cancers was 52.54 years, compared to 61.53 for all other groups. After adjusting for age, the synchronous cancers continue to have the highest survival with a statistically significant HR of 0.74 (p=0.005). The most common histology type for synchronous cancers was endometrioid for both uterine and ovarian (n=593), with endometrioid uterine and serous ovarian histology types being the second most common (n=42). In a subgroup analysis with grade I endometrioid carcinomas of the uterus and ovary versus primary grade I endometrioid NS stage I of the ovary and NS stage I of the uterus, the improved survival relationship remains for the synchronous cancers (HR: 0.86, 0.60). In a similar subgroup limited to those patients with known chemotherapy or radiation treatment, those with synchronous cancers continue to have improved survival comparatively (HR: 0.54, 0.55). Conclusions: Contrary to our hypothesis, those diagnosed with synchronous cancers had improved survival than NS stage I primary uterine or ovarian cancers and stage IIIA uterine cancers. The survival advantage of patients with synchronous tumors is attributed to factors, including younger age, endometrioid histology, lower grade, and receipt of adjuvant treatment; however, after adjusting for these variables, the survival benefit relationship continued. Further studies need to be done for improved understanding, including HRD and molecular testing, which we are currently investigating. Objectives: The objectives of this epidemiologic study were to investigate potential misdiagnosis of synchronous endometrial and ovarian cancers, utilizing the Surveillance Epidemiology and End Results (SEER) Program, which is a population-based tumor registry. We hypothesize that women diagnosed with synchronous tumors may have worse overall survival than those with nonsynchronous stage I tumors, closer to stage IIIA endometrial cancer due to misdiagnosis and potential undertreatment. Methods: This retrospective observational study utilized the SEER database to compare synchronous uterine and ovarian cancers cases to those of separate, primary endometrial and ovarian cancers. Kaplan-Meier analyses were used to construct overall survival curves, which were compared with log-rank tests. Cox proportional hazard regression models were utilized to adjust for age, adjuvant treatments, and histologic and grade subgroup pairings. Magnitudes of statistical significance were expressed with age-adjusted HR and 95% CI. Results: Women with stage I synchronous tumors had the highest progression-free survival of all groups compared to stage I non-syn- chronous (NS) ovarian and uterine cancers and NS stage IIIA uterine cancers with an HR of 0.44. The mean age at diagnosis for synchronous cancers was 52.54 years, compared to 61.53 for all other groups. After adjusting for age, the synchronous cancers continue to have the highest survival with a statistically significant HR of 0.74 (p=0.005). The most common histology type for synchronous cancers was endometrioid for both uterine and ovarian (n=593), with endometrioid uterine and serous ovarian histology types being the second most common (n=42). In a subgroup analysis with grade I endometrioid carcinomas of the uterus and ovary versus primary grade I endometrioid NS stage I of the ovary and NS stage I of the uterus, the improved survival relationship remains for the synchronous cancers (HR: 0.86, 0.60). In a similar subgroup limited to those patients with known chemotherapy or radiation treatment, those with synchronous cancers continue to have improved survival comparatively (HR: 0.54, 0.55). Conclusions: Contrary to our hypothesis, those diagnosed with synchronous cancers had improved survival than NS stage I primary uterine or ovarian cancers and stage IIIA uterine cancers. The survival advantage of patients with synchronous tumors is attributed to factors, including younger age, endometrioid histology, lower grade, and receipt of adjuvant treatment; however, after adjusting for these variables, the survival benefit relationship continued. Further studies need to be done for improved understanding, including HRD and molecular testing, which we are currently investigating.