Molecular Sequencing Of Serous Endometrial Carcinoma From Patients With Or Without Early Recurrence: A Pilot Study

Objectives: This study evaluates the mutational burden and molecular profile of stage I serous endometrial carcinoma (SEC) in patients who experienced an early recurrence (within 24 months of surgical staging) compared with those without early recurrence. We hypothesize that differences in the molecular profile impacts the patients' disease-free survival. Methods: Cases were identified among patients treated between 2010 and 2017 with a new diagnosis of SEC. The diagnosis was made based on hematoxylin and eosin stained tissue sections and/or immunohistochemical staining consistent with TP53 mutation. Tumors from four patients without early recurrence (followed for 40-62 months) and three patients with early recurrence (17-22 months from staging surgery) were analyzed. Next generation molecular sequencing was performed from paraffin-embedded tissue from each case. The number of mutations, molecular profile, as well as other patient characteristics were compared between the two groups. Results: A statistically significantly higher mutational burden among the group without early recurrence and a statistically significantly higher Body mass index among the group with early recurrence was found. A mutation of the SETD2 gene was found only in tumors from patients without recurrence and was not present in any of the tumors from patients with early recurrence. Conclusion: This study found a statistically significantly lower mutation burden in SECs from patients who had early recurrence compared to those without early recurrence. It is hypothesized that higher mutational burden favorably changes the prognosis of SEC. We also found an SETD2 mutation only in tumors of patients who had not experienced a recurrence. Further research is needed to confirm these findings.