Association of number of positive nodes and cervical stroma invasion with outcome of advanced endometrial cancer treated with chemotherapy or whole abdominal irradiation: a Gynecologic Oncology Group study.
To determine whether the number of positive pelvic nodes (PPN), cervical stromal involvement (CSI), and/or lymphovascular space involvement (LVSI) were prognostic factors among women with advanced endometrial carcinoma treated with adriamycin plus cisplatin (AP) or whole abdominal irradiation (WAI). Data were abstracted from records of patients treated with adjuvant WAI or AP in a GOG randomized trial. Cox proportional hazards models were used to estimate the association of CSI and PPN with differences in PFS and OS while adjusting for treatment and previously studied factors. WAI was randomly allocated to 202 and AP to 194 eligible patients. CSI (n=93 total) was associated with a 44% increase in risk of progression and a 33% increase in risk of death. There was a trend for increasing number PPN being associated with a 7% per positive node increase in risk of progression/death. For CSI, the estimated unadjusted treatment hazard ratios (HRs) were: PFS 0.85 (0.53, 1.38); OS 0.81 (0.50, 1.33). For metastatic disease limited to a single PPN (n=25), the unadjusted HRs were: PFS 0.96 (0.34, 2.74); OS 0.73 (0.24, 2.18). The test of homogeneity of treatment effect (ie., AP vs WAI) across subgroups (CSI, number of positive pelvic nodes) was not statistically significant for either endpoint, thus supporting the superiority of chemotherapy as reported in the original manuscript. The presence of CSI and increasing number of PPN were associated with poor prognosis. On average, patients with CSI experienced improved PFS and OS when treated with AP relative to WAI.