Similarly, women who
received chemotherapy prior to surgery were excluded and only those
patients who survived for more than 6 months after cancer-directed
surgery were included in the analysis. Patients were risk stratified
based on previously published data: low-risk (stage IA or IB, grade 1
or 2, non-clear cell histology), high-risk (stage IA or IB grade 3, any
stage clear cell histology, stage IC any grade) and unknown risk (insufficient
data on grade available to further classify)