A phase III trial of surgery with or without adjunctive external pelvic radiation therapy in intermediate risk endometrial adenocarcinoma: a Gynecologic Oncology Group study
Introduction
Every year more than 36,000 women are diagnosed with adenocarcinoma of the endometrium [1]. Historically, many of these women have received postoperative radiation based on the belief that this treatment would decrease relapses [2], [3], [4], [5]. Data supporting this routine treatment are largely from single-institution retrospective reports [6], [7]. There seems to be increasing agreement that women presenting with noninvasive endometrial adenocarcinoma are at such a low risk of recurrent disease that radiation therapy (RT) should not be included in their treatment plan. The use of radiation therapy for International Federation of Gynaecology and Obstetrics (FIGO) stages IB, IC, and II (occult) remains controversial in endometrial adenocarcinoma [10], [11]. Creutzberg et al. [8] examined this question in a prospective randomized study. Their data suggested that postoperative radiation therapy reduces locoregional recurrence in stage I endometrial carcinoma but is not indicated in women under 60 years and those with grade 2, superficially invasive tumors. Analysis of their study is limited as complete surgical staging was not an entry requirement and the actual number of women with FIGO stage I endometrial adenocarcinoma remains unclear. To address the utility of postoperative radiation therapy in women with stage IB, IC, and II (occult) endometrial cancer, the Gynecologic Oncology Group (GOG) initiated this study.
Section snippets
Materials and methods
For this study, intermediate risk endometrial adenocarcinoma was defined based on data from a surgical staging protocol (GOG # 33) [9]. These data suggested that all women found to have any degree of myometrial invasion with adenocarcinoma of any grade and no evidence of lymph node involvement (International Federation of Gynaecology and Obstetrics [FIGO] stage IB, IC, IIA (occult), and IIB [occult]) should be considered as a member of the intermediate risk group, expected to have a 5-year
Results
Between June 1987 and July 1995, 448 women were entered into this study. After central evaluation, 392 women (88%) were determined to be eligible. Of the 56 women found to be ineligible (25 assigned to NAT and 31 assigned to RT), the GOG Gynecologic Oncology Committee determined that 38 women (8.5%) had incomplete staging; the majority had unilateral, instead of the required bilateral lymph node sampling. The remaining 18 women (4%) were found to have an ineligible histology or FIGO stage. All
Discussion
The role of adjuvant postoperative irradiation has been studied previously in two large randomized trials, neither of which required detailed surgical staging evaluation. A Norwegian from the 1970s followed 540 stage I endometrial cancer patients who were randomly assigned to receive either vaginal irradiation alone (control group) or vaginal plus external pelvic radiation therapy [23]. The latter group had fewer vaginal and pelvic recurrences (1.9 versus 6.9% P < 0.01) than the control group,
Acknowledgements
Supported by National Cancer Institute grants of the Gynecologic Oncology Group Administrative Office (CA 27469) and the Gynecologic Oncology Group Statistical Office (CA 37517). The following Gynecologic Oncology Group institutions participated in this study. University of Alabama at Birmingham, Oregon Health Sciences University, Duke University Medical Center, Abington Memorial Hospital, University of Rochester Medical Center, Walter Reed Army Medical Center, University of Minnesota Medical
References (23)
- et al.
Postoperative radiation therapy for surgically staged endometrial cancer: impact of time factors (overall treatment time and surgery-to-radiation interval) on outcome
Int. J. Radiat. Oncol. Biol. Phys.
(1995) - et al.
An analysis of approaches to the management of endometrial cancer in North America: a CTF study
Gynecol. Oncol.
(1998) - et al.
An analysis of approaches to the treatment of endometrial cancer in Western Europe: a CTF study
Eur. J. Cancer
(1995) - et al.
Relationship between surgical–pathological risk factors and outcome in clinical stages I and II carcinoma of the endometrium (a Gynecologic Oncology Group study)
Gynecol. Oncol.
(1991) - et al.
Risk factors and recurrent patterns in stage I endometrial cancer
Am. J. Obstet. Gynecol.
(1985) - et al.
Planning and duration of a comparative clinical trial with loss to follow-up and a period of continued observation
J. Chronic Dis.
(1981) - et al.
Patterns of failure in endometrial carcinoma stage IB grade 3 and IC patients treated with postoperative vaginal vault brachytherapy
Gynecol. Oncol.
(1999) - et al.
Cancer statistics 2000
CA Cancer J. Clin.
(2000) - et al.
Surgical pathological staging of endometrial carcinoma and results of treatment
Eur. J. Gynaecol. Oncol.
(1992) The value of preoperative or postoperative treatment by radium for carcinoma of the uterine body
Surg., Gynecol. Obstet.
(1971)
A prospective trial comparing hysterectomy, hysterectomy plus vaginal radium and uterine radium plus hysterectomy in stage I endometrial carcinoma
Obstet. Gynecol.
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