The role of lymph node dissection in advanced endometrial cancer
Advanced EC is defined as stage III or IV endometrial carcinoma of any histology(5). LND has proved efficacious in diagnosing advanced cancer in high-risk patients(5), tailoring adjuvant therapy for those with adverse pathological features(33) (Table 3). LND also has a vital prognostic role in advanced EC(25,38). These findings are supported by a multicentre study, which concluded that LN ratio (the proportion of metastatic LNs to the total number of removed LNs) is the strongest independent prognostic parameter in stage IIIC patients. LN ratio of <10% and >50% are associated with a significant difference in 5-year OS(25).
In stage IIIC EC, a recent study by Multinu et al. concluded that LND can be omitted from surgical staging of “non-bulky” nodal disease as combined adjuvant therapy (chemotherapy and EBRT) proved to be effective alone(39). This result cannot be extrapolated to “bulky” and “suspicious nodes”, as these were not included in this study. This novel finding differentiates “bulky” and “non-bulky” nodal disease previously unmentioned by ESMO-ESGO-ESTRO 2016, although Multinu et al. fails to define these terms clearly. Other studies have defined bulky nodal disease as >1cm(34). Nonetheless, this may reinforce the therapeutic benefit of LND specifically in advanced bulky nodal disease. For stage III EC, the ESMO-ESGO-ESTRO 2016(5) supported by the newer SEOM guidelines(40) recommend radical cytoreductive surgery (debulking), which is defined as reducing the volume of a tumour to the greatest extent possible(41). The Gynaecologic Oncology Group (GOG) recommends reducing gross residual disease to ≤1cm(41). In addition, LND prior to cytoreductive surgery resulted in better survival outcomes(42,43).
The effect of LND on non-endometrioid type cancers is not well-characterised given the low number of this histological subtype(39). Therapy options are limited for advanced EC with extra-abdominal metastases, and there is no widely acknowledged agreement regarding treatment of stage IVB EC(5,44). Therefore, the prognosis for stage IVB EC remains extremely poor with the 5-year disease specific survival (DSS) of ~5%. In this case, aggressive cytoreductive surgery to reduce tumour size could be beneficial(45).