Clinical significance of radiotherapy in patients with primary uterine carcinosarcoma: a multicenter retrospective study (KROG 13-08)

OBJECTIVE To investigate the role of radiotherapy (RT) in patients who underwent hysterectomy for uterine carcinosarcoma (UCS). METHODS Patients with the International Federation of Gynecology and Obstetrics stage I-IVa UCS who were treated between 1990 and 2012 were identified retrospectively in a multi-institutional database. Of 235 identified patients, 97 (41.3%) received adjuvant RT. Twenty-two patients with a history of previous pelvic RT were analyzed separately. Survival outcomes were assessed using the Kaplan-Meier method and Cox proportional hazards model. RESULTS Patients with a previous history of pelvic RT had poor survival outcomes, and 72.6% of these patients experienced locoregional recurrence; however, none received RT after a diagnosis of UCS. Univariate analyses revealed that pelvic lymphadenectomy (PLND) and para-aortic lymph node sampling were significant factors for locoregional recurrence-free survival (LRRFS) and disease-free survival (DFS). Among patients without previous pelvic RT, the percentage of locoregional failure was lower for those who received adjuvant RT than for those who did not (28.5% vs. 17.5%, p=0.107). Multivariate analysis revealed significant correlations between PLND and LRRFS, distant metastasis-free survival, and DFS. In subgroup analyses, RT significantly improved the 5-year LRRFS rate of patients who did not undergo PLND (52.7% vs. 18.7% for non-RT, p<0.001). CONCLUSION Adjuvant RT decreased the risk of locoregional recurrence after hysterectomy for UCS, particularly in patients without surgical nodal staging. Given the poorer locoregional outcomes of patients previously subjected to pelvic RT, meticulous re-administration of RT might improve locoregional control while leading to less toxicity in these patients.