Combined Modality Treatment Favorably Impacts Survival in Women with Stage I Uterine Serous Carcinoma: A National Cancer Database Analysis
Ghanem AI, Modh A, Khalil R, Lee JK, and Elshaikh MA. Combined Modality Treatment Favorably Impacts Survival in Women with Stage I Uterine Serous Carcinoma: A National Cancer Database Analysis. Int J Radiat Oncol Biol Phys 2019; 103(5):E12.
Int J Radiat Oncol Biol Phys
Background: Uterine serous carcinoma (USC) is a rare and aggressive type of endometrial cancer. There is ongoing controversy regarding the role adjuvant radiation therapy (RT) or chemotherapy (CT) for early stage USC due to the lack of prospective trials addressing this group exclusively. Objectives: We sought to assess patient characteristics and overall survival (OS) across various treatment modalities for FIGO-stage I USC using the National Cancer Database (NCDB). Methods: The NCDB was queried for USC patients with FIGO-2009 stage I who underwent surgical staging followed by adjuvant RT, CT, combined modality (CRT) or observation (OB) from 2004 to 2013. Cases whose adjuvant therapy started after 6 months and cases with missing follow up and pathological data were excluded. RT was either external beam RT (EBRT) within the dose range of 45–50 Gy, vaginal brachytherapy (VB) or both and should have concluded within an 8 weeks interval to be included. Demographic and clinico-pathological data were compared across the study groups: OB, RT alone, CT alone or CRT using t-test and Chi-squared tests. Log-rank p-values and Kaplan-Meier curves were created for OS analysis for the 4 study groups. Results: We were able to identify a total of 3634 cases that met our inclusion criteria after excluding 725 cases. The median follow up time was 40.7 months (0–130.4). Median age was 67 years and 74% of cases were white. Women with FIGO-2009 stage IA and IB represented 77% and 18% of the study cohort (5% were stage I (NOS)). RT alone, CT alone, CRT and OB were utilized by 401(11%), 789 (21.7%), 609 (16.8%) and 1835 (50.5%) of the study population, respectively. Of those that received RT, VB was used in 68% of patients, EBRT in 11% and a combination in 21%. CT alone and CRT were offered more to patients <70 years, those with private insurance, those diagnosed in 2007-2012 and in cases with regional LN dissection (p<0.001). Patients were more likely to be observed if they had a higher comorbidity score, stage IA and diagnosis from 2004–2006 (p<0.005). Patients were more likely to receive EBRT than VB if they were treated with RT alone (p<0.001). Five year OS was (78.6%, 78.5%, 88.5% and 90.1%) for cases treated with OB, RT alone, CT alone and CRT respectively (p<0.001). CRT was associated with better OS than RT alone (p<0.001), CT alone (p=0.068) and OB (p<0.001) using log-rank risk. Conclusions: Combined modality is more utilized over time for cases with stage I USC and it is associated with significantly improved outcomes compared to other approaches. The important role of combined radiotherapy and chemotherapy for early stage USC needs to be investigated in the setting of a prospective randomized study.