Choice of the treatment method of low-risk endometrial cancer

Abstract

So far, the issue of radiotherapy (RT) employment in the management of stage I low-risk endometrial cancer (EC) patients remains controversial. Stage IA, grade 1-2 endometrioid adenocarcinoma is qualified as low-risk. The paper presents the outcomes of surgical (ST) and combination treatment (CT) of low-risk EC patients between 2006 and 2010. There were three most commonly used treatment options in the CT group: 1) preoperative brachytherapy (PBT) plus surgery, its magnitude being hysterectomy with bilateral salpingo-oophorectomy (HS) (1239 patents); 2) PBT + HS + postoperative external-beam RT (ERT) (1051); 3) HS + ERT (429). A single PBT was performed on the day before surgery at a single target dose of 13.5 Gy, ERT was carried out with conventional fractions of 2 Gy up to a total target dose of 40-44 Gy. Overall 5-year survival with CT was 90.6 %, ST - 87.8 %, cancer-specific survival was 94.6 % and 94.5 %, respectively (р > 0.05). No statistically significant differences between CT and ST (р > 0.05) were found in overall and cancer-specific survivals for stage IAG1 EC without myometrium invasion and for stage IAG2 EC without myometrium invasion. Statistically significant differences in overall survival (р = 0.001) were documented for stage IAG1 EC with myometrium invasion up to 1/2 of its thickness; however, they were not observed in cancer-specific survival (р > 0.05). Overall and cancer-specific survivals for stage IAG2 EC with myometrium invasion up to 1/2 of its thickness appeared to be significantly higher with CT than with ST (р = 0.00004 and р = 0.002). The highest efficacy was attained using CT with PBT and/without postoperative ERT, compared with ST and other CT options. A differentiated approach to RT is needed for low-risk EC. RT is recommended to be completely rejected for stage IAG1-2 EC without myometrium invasion. It is possible to refrain from using RT for stage IAG1 EC with myometrium invasion up to 1/2 of its thickness. There are no reasons to completely reject RT for stage IAG2 EC. Further research is needed to assess the role of RT for stage IAG1-2 EC with myometrium invasion up to 1/2 of its thickness.