Endometrial serous carcinoma: Association between race and ethnicity, mutational status, sites of metastasis and recurrence, and correlation with overall survival (205)

Abstract

<b>Objectives:</b> There are significant racial disparities in endometrial cancer (EC) survival rates, partly due to the higher risk of type II EC in Black women. Our objective was to investigate the association between sites of recurrence and metastases of uterine serous carcinoma (USC), mutational status, race, and overall survival (OS). <b>Methods:</b> This single-center retrospective study evaluated patients with biopsy-proven USC who underwent genomic molecular testing between January 2015 and July 2021. Association between genomic profile and sites of metastases or recurrence was performed using Chi-square or Fisher's exact test. Survival curves for the ethnicity and race, mutations, sites of recurrence, and metastases were estimated using the Kaplan-Meier method and compared with the log-rank test. Age, race, ethnicity, mutational status, and sites of metastatic/ recurrence were correlated with OS using univariable Cox proportional hazard models. A p-value of <0.05 was considered statistically significant. <b>Results:</b> The study included 67 women (median age: 66 years, range: 44-82). Of these, 52 were non-Hispanic, 14 were Hispanic, and one was of unknown ethnicity. Thirty-two women were Black (all non-Hispanic), 32 were White, and three were of unknown or other races. Among the included women, 48 had advanced-stage USC at diagnosis. The most common sites of metastasis/recurrence were lymph nodes (36/67; 54%), followed by peritoneum (31/67; 46%), pelvis (12/67; 18%), and liver (6/67; 9%). The most common mutations were <i>TP53</i> mutation (52/55, 95%), followed by <i>PI3KCA</i> (14/58, 24%) and <i>PTEN</i> (5/49, 10%). Estrogen receptor (ER) was expressed in 39/61 (64%) cases tested on immunohistochemistry. Non-Hispanic ethnicity was associated with lower OS (p=0.047), although we did not find a difference in the risk ratio between Hispanic and non-Hispanic ethnicity (RR: 1.94; 95% CI: 0.99-3.8; p=0.05).Fig. 1 <b>Conclusions:</b> <i>TP53</i> and <i>PI3KCA</i> are often mutated in USC, and ER is expressed in the majority of USC. USC most commonly metastasizes/recurs to the lymph nodes and the peritoneum. Overall survival of Hispanic women was lower than non-Hispanic women, although we could not identify a difference in risk ratio between the different ethnicities.