Results
Among the 46,313 patients described in the database, 1405 were included
in this study (427 patients in the low-volume group, 396 patients in the
mid-volume group and 582 patients in the high-volume group). The flow
diagram of recruitment and exclusion is illustrated in Figure 1. The
median follow-up time was 30 months (interquartile range, 19·0-45·0).
The clinicopathologic characteristics of the three groups are provided
in Table 1. The patients in the high-volume group were more likely to
have LVSI (P = 0·004) and lymph node metastasis (P = 0·002); those in
the mid- and high-volume groups were more likely to have deep stromal
and uterine invasion than were those in the low-volume group (all P
< 0·05).