Adjuvant therapy in patients with clear cell endometrial carcinoma: An analysis of the National Cancer Database.

OBJECTIVE: To assess the impact of adjuvant treatment, sociodemographic and tumor factors on the survival of patients with non-metastatic clear cell endometrial carcinoma (CCC).

METHODS: 4298 patients treated from 1998 to 2011 with Stage I-IVA CCC were identified within the National Cancer Database. FIGO 2009 staging system was used. Adjuvant groups included: hysterectomy (HYS); HYS+vaginal brachytherapy (VBT); HYS+chemotherapy (CT); HYS+external beam radiation therapy (EBRT); HYS+CT+EBRT; and HYS+CT+VBT. Univariable (UVA) and multivariable (MVA) frailty survival analyses were performed.

RESULTS: On UVA, higher stage was associated with an increased risk of death. Compared to stage I-IA, the risk of death for stage IB was HR 1.75 (95% CI, 1.50-2.04; p<0.001), stage II was HR 1.77 (95% CI, 1.50-2.10; p<0.001), stage III-IIIB was HR 3.29 (95% CI, 2.86-3.80; p<0.001), stage IIIC-IIIC2 was HR 3.33 (95% CI: 2.94-3.77; p<0.001), and stage IVA was 8.59 (95% CI: 6.60-11.18; p<0.001). Other meaningful predictors of death included black race (p<0.001), public insurance (p<0.001), geographic education attainment (p=0.001), greater comorbidity score (p=0.001), increasing age (p<0.001), and increasing tumor size (p<0.001). After controlling for stage, insurance, race, education attainment, comorbidity score, age, and tumor size adjuvant treatment was not associated with decreased risk of mortality (p=0.26).

CONCLUSION: Adjuvant therapy did not have a meaningful effect on survival in this sample from the National Cancer Center Database. Given the aggressive nature of the disease, clinical trials are required to determine the optimal adjuvant therapy in patients with non-metastatic CCC to improve clinical outcomes.