METHODS
Two hundred sixty-three patients with stage I endometrial
adenocarcinoma, who were treated with postoperative
radiotherapy between 1978 and 1998, were analyzed
retrospectively. According to the 1988-FIGO staging system,
the disease was stage IA in 19, stage IB in 128, and stage IC
in 116 patients. One hundred and ninety-seven patients were
treated with external and intracavitary irradiation, 45 patients
with external radiotherapy and 21 patients with vaginal
brachytherapy.
RESULTS
The 10-year local control, disease-free and actuarial survival
rates were 96%, 93% and 95%, respectively. Fifty-five
patients had late side effects. The late side effects were
significantly higher in patients with acute toxicity and patients
who were treated with external radiotherapy, followed by
brachytherapy.
CONCLUSION
The decision of adjuvant therapy and choice of different treatment
modalities in terms of a reduced risk of recurrence need
to be weighed carefully against the treatment-related morbidity.
Keywords: Endometrial cancer; stage I; postoperative radiotherapy; long-term results
During external pelvic radiation treatment of
endometrial carcinoma, other pelvic organs receive
a significant radiation dose, resulting in both acute
side effects and late complications.[
The aim of this retrospective study was to assess
the results of postoperative radiotherapy, patterns
of failure and late complications in patients
with stage I endometrial carcinoma who were
treated before 1999.
Patients were evaluated with physical and pelvic
examination, routine blood counts, blood chemistry
profile including renal and hepatic function
tests and chest X-ray. After the year 1989, most
patients underwent abdominopelvic computerized
tomography and/or pelvic magnetic resonance imaging.
Patients were staged according to the FIGO
1988 pathologic staging. The patients who were
treated before 1988, they were restaged according
to FIGO 1988 staging. The patients’ age ranged
from 31 to 83 years, with a median of 57 years. The
patient characteristics are summarized in Table
Treatment
A simple hysterectomy was performed in 229
patients and 34 patients underwent radical hysterectomy.
Peritoneal cytology was examined in 47
(17.9%) patients. All patients were evaluated according
to indication of adjuvant radiotherapy. One
hundred and ninety-seven (74.9%) patients were
treated with external pelvic radiotherapy followed by vaginal brachytherapy and 45 patients (17.1%)
were treated with only external pelvic irradiation.
Remaining 21 (8%) patients treated with vaginal
cuff irradiation alone. Patients treated with both
external and intracavitary radiotherapy, were initially
treated with external pelvic irradiation.
In external pelvic radiotherapy, standard pelvic fields were used. The field borders extend from the L4-L5 interspace to the obturator foramen. Laterally, the fields extend 1.5 to 2.0 cm from the widest plane of the true pelvis. The radiotherapy technique consisted of an anterior and posterior pair in 195 (74.1%) patients, a four-field box technique (anteroposterior, posteroanterior, and two lateral fields) in 47 (17.9%) patients. During external irradiation, midline shielding was not used. The radiation dose was specified at the patient’s midplane or at the isocentre of the fields. The total pelvic dose was median 50.4 Gy (45-54 Gy) with a daily dose of 1.8-2 Gy. In external pelvic irradiation, Co60 teletherapy device or 18 MV photons of linear accelerator were used.
Low-dose-rate radium source was used in intracavitary applications until the 1981; high-dose rate accelerated Curietron Co60 afterloading system has been used from that date on. Vaginal cuff HDR irradiation was performed in 215 (98.6%) patients. Each implant was performed at one week intervals. The vaginal cuff irradiation was performed with Fletcher-Suit HDR colpostats or vaginal cylinder. Patients treated with HDR brachytherapy each received three fractions of 8 Gy and the dose specified at 0.5 cm from the surface of the applicator.
Follow-up
During radiotherapy treatment, all patients
were routinely reviewed once a week and patients
underwent weekly blood tests. After the treatment,
patients were seen monthly to assess acute
reactions. Then, all patients were followed regularly
with physical and pelvic examination every
3 months for 2 years, every 6 months between 3
and 5 years, and yearly thereafter. Chest X-rays,
routine blood chemistry profiles were repeated in
every 6 months. In the suspicious of the recurrence
and/or metastases, other radiological examinations were required. Vaginal smears or biopsy samples
were taken on indication. Loco-regional recurrences
were confirmed by a biopsy sample. Acute
and late toxic effects of radiotherapy were scored
according to the Radiation Therapy Oncology
Group/European Organization for Research and
Treatment of Cancer (RTOG/EORTC) acute and
late morbidity criteria.
Prognostic factors and statistical methods
Pelvic and local control, disease free survival
and actuarial survival rates were calculated using
the Kaplan-Meier method. Differences between
curves were compared by the long rank test. Survival
was measured from the operation date. Variables
were compared using student-t, Mann-Whitney-
U or chi-square test according to the variable
properties. Univarite and multivariate analysis of
prognostic factors were performed using log-rank
and Cox regression models, respectively. All reported
p-values are based on two-sided tests with
p<0.005 taken to be significant.
Of 263 patients, 17 (6.5%) had a relapse, and
their clinical, pathologic, and treatment characteristics
are shown in Table
Distant metastasis was noted in 13 (4.9%) patients after median 21 months (range: 9-35 months). Among 13 patients, 9 of them had stage IC disease. The most common sites of distant relapse were the lung in 8 patients, omentum in 7 patients. All patients with omentum metastasis had received pelvic external radiotherapy and 5 of them had stage IC, 4 of them had grade 3 disease. All patients with metastases died with disease.
Univariate analysis
Prognostic factors that might influence local
control, disease free survival and actuarial survival
were subjected to univariate analysis. These factors
included age (≥60 years vs. <60 years), grade,
stage, myometrial invasion, treatment type, time to
radiotherapy after surgery, external treatment time,
duration between external and intracavitary irradiation.
However, no factor significantly influences 10-year pelvic and local control, disease-free and
actuarial survival rates.
Acute and late side effects
Among the 263 patients, acute radiation side
effects were documented in 116 (44.1%) patients.
The majority of patients developed acute grade 1
skin reactions (22%) and grade 1 gastrointestinal
tract side effects (20.9%). Grade 3 gastrointestinal
toxicity was detected in 2 patients and grade 3 skin
reactions was seen in 3 (1.1%) patients and all of
them treated with external radiotherapy with Co60
machine. Acute complications are shown in Table
Fifty-five (20.9%) patients had late side effects.
The median time to the development of late complications
was 22 month (6-84 months). The most
common late side effect was in the gastrointestinal
tract (Table
ERT: External pelvic radiotherapy; VBT: Vaginal brachytherapy.
Numerous studies have demonstrated that age,
depth of myometrial invasion, histology subtypes,
histologic grade, cervical involvement, lymphovascular
space involvement, nodal involvement
can predict recurrence and survival in patients with
endometrial cancer.[
There have been controversies concerning the
indications and types of adjuvant radiation therapy
for stage I endometrial cancer. Recently, randomized
studies (NHR, PORTEC 1 & 2, GOG 99,
MRC, NCIC) regarding adjuvant radiotherapy for
early-stage endometrial cancers were performed.
[
Clinical stage I disease has recently emerged
in the form of a meta-analysis of five randomised
trials of adjuvant radiotherapy.[
The 5-year local control, disease-free and actuarial
survival rates of 97%, 93% and 95%, respectively,
for the stage I patients of our study are comparable
with the results of previous reports. It has been confirmed that 68% to 100% of recurrences
occur within the first 3 years of diagnosis.[
Since stage I endometrial cancer have an excellent
outcome, many women with endometrial
adenocarcinoma live for many years with the consequences
of treatment related toxicity.[
Postoperative brachytherapy alone is recommended
to reduce the risk of vaginal cuff recurrence with less toxicty in women with intermediate-risk
disease in both retrospective and randomized studies.[
Treatment related factors that are related to the
risk of complications are treatment volume, daily
fractionation, radiotherapy technique.[
In conclusion, the benefit of adjuvant therapy
in terms of a reduced risk of recurrence needs to
be weighted carefully against the treatment related
morbidity when deciding on treatment protocols
for stage I endometrial carcinoma. Individual patient,
the tumor characteristics should be considered.
If administered, the least aggressive and modern
radiotherapy approaches (conformal, intensity
modulated radiotherapy-IMRT) should be used to
reduce the rate of both acute and late side effects.