N. Posever1, A. E. Rosenthal1, K. M. Esselen2, and J. W. Jang2; 1Harvard Medical School, Boston, MA, 2Beth Israel Deaconess Medical Center, Boston, MA
Purpose/Objective(s):Our study examines clinical outcomes of stage III serous endometrial cancer patients treated with adjuvant chemotherapy vs combined chemotherapy and radiation. We assessed differences in recurrence free survival (RFS), overall survival (OS), and initial recurrence site. Materials/
Methods: A retrospective cohort study was conducted including all stage III serous endometrial cancer patients treated at our institution from 2010-2021. Data was abstracted from the medical record and from chart review. Outcomes were compared between patients who received chemotherapy alone (“chemotherapy” group) vsany sequence combining chemotherapy and radiation (“sequential” group).Patients in the chemotherapy group received up to six cycles of carboplatin and paclitaxel. Patients in the sequentialgroup received external beam radiation (EBRT) and/or vaginal brachytherapy (VBT) with or without sensitizing cisplatin and with or without up to 4 cycles of outback carboplatin and paclitaxel, or sandwich adjuvant therapy with three cycles of carboplatin and paclitaxelfollowed by radiation followed by up to 3 additional cycles of carboplatin and paclitaxel. Univariate analyses were performed using fisher’s exact,Wilcoxon rank-sum, and logranktests. Results: A total of 53 patients were included in the study. Among them, 11 patients received chemotherapy and42 received sequential treatment.Both groups were similar with regards to age, race,stage and comorbidities.In the sequentialgroup, 26 patients received both EBRT and VBT, 11 received only EBRT, and 5 received only VBT. RFS was significantly improved for the sequential group compared to the chemotherapy group (24.5 months vs 10.3 months, p=0.04).Although there was a large absolute difference in OS between groups (24.5 vs 46.9 months), this was not statistically significant(p=0.25). Local recurrence was significantly more likely in the chemotherapy group (45.5% vs 11.9%, p=0.02). There was no difference in nodal (p>0.99)or distant (p=0.59)recurrence. Conclusion: Stage III serous endometrial cancer patients treated with a combination of adjuvant radiation and chemotherapy had improved RFS when compared to patients treated with adjuvant chemotherapy alone. OS was not significantly different between groups. Patients treated with a combination of radiation and chemotherapywere less likely to recur locally with no significantly increased risk in distant or nodal recurrence. These findings suggest that adjuvant treatment combining chemotherapy and radiation may increase recurrence free survival in this patient population and should befurther evaluated in future clinical trials.
