METHODS
Medical records of 571 patients who were treated with adjuvant radiotherapy or radiochemotherapy between
2001 and 2018 were retrospectively reviewed. Differences in overall survival (OS) and progression-free survival
(PFS) rates according to FIGO 2009 and FIGO 2018 staging systems were compared using the log-rank test. Cox
regression model was used to identify independent prognostic factors for survival.
RESULTS
The median follow-up was 59 months. Five-year OS and PFS rates were 81.1% and 77.7%, respectively. Stage
migration was recorded in 401 patients (70.2%) and the most remarkable stage migration was detected in stage I
patients (60%). A total of 157 (27.5%) patients upstaged to stage IIIC disease. According to FIGO 2009, 5-year OS
rates were 87.3%, 80.5% (p=0.076), and PFS rates were 82.8%, 77.5% (p=0.036) for stage IB1 and IB2, respectively.
According to FIGO 2018, the 5-year OS rates for stage IB1, IB2, and IB3 were 89.8%, 87.1%, and 81.4% (p=0.310),
and PFS rates were 90.2%, 80.5%, and 80.1% (p=0.189), respectively. Patients with ?2 pelvic lymph node (LN)
metastases had worse 5-year OS and PFS rates than patients with one metastasis (p=0.015 and p=0.006). Number
of para-aortic LN metastasis and metastatic LN ratio (MLNR) were also correlated with 5-year OS and PFS.
CONCLUSION
Current FIGO staging system better discriminates patients with cervical cancer. However, integration of
metastatic LN number and/or MLNR to the upcoming FIGO staging system may improve the prognostic
value of the staging.
Keywords: Cervical cancer; FIGO staging; lymph node metastasis; radiotherapy
Staging often plays a critical role in the assessment
of cancer spread and the development of treatment
strategies. The most widely accepted staging system for
cervical cancer is the International Federation of Gynecology
and Obstetrics (FIGO) staging system. FIGO
was originally founded in 1954, and the cervical cancer
stage classification was developed shortly thereafter.[
The staging has undergone multiple modifications
since that time, the former staging system was published
in 2009.[
The main goal of this study was to restage cervical
cancer patients treated with radical hysterectomy (RH),
followed by adjuvant radiotherapy (RT) or radiochemotherapy
(RCT) and demonstrate stage migration according
to the current FIGO 2018 staging system. We
also aimed to analyze the basic prognostic factors and
their impact on survival outcomes.
Staging
In the former FIGO 2009 staging system, the patient"s
stage was mainly based on gynecologic examination
by the clinician. The current FIGO 2018 staging system
integrated the data from imaging modalities and
pathologic evaluation in addition to the gynecologic
examinations as well. In this study, all patients were
staged according to both FIGO 2009 and 2018 staging
systems. Patients with metastatic disease, recurrent
disease, synchronous malignancy, and who were lost to
follow-up were excluded from this study.
Surgery
All patients underwent radical surgery before RT. The
surgical procedure was performed in the form of RH
plus bilateral salpingo-oophorectomy, with pelvic and/or
para-aortic LN surgery (sampling or dissection-LND).
Less than 10 dissected LN was considered as sampling.
All dissected LNs were pathologically evaluated.
Isolated tumor cells were defined as cells or masses of
cells measuring ≤0.2 mm; micrometastases were defined
as tumors larger than 0.2 mm but ≤2 mm; and
macrometastases were defined as tumors >2 mm.
Nodal Staging
RT/RCT
RT was administered as external RT±vaginal cuff
brachytherapy (VCB). External RT was in the form of
external pelvic RT with conventional daily doses to a
total dose of 45-59.4 Gy (median 45 Gy). Para-aortic
fields were added when there were para-aortic LN metastases
and lower para-aortic lymphatics were included
when there were common iliac LN metastases. VCB
when used was applied to the proximal 3-5 cm of the vagina and the dose was prescribed to the vaginal mucosa
or 5 mm depth from the vaginal surface according
to the American Brachytherapy Society recommendations.[
Follow-up
Statistical Methods
The primary endpoints were identifying stage migration
between FIGO 2009 and 2018 staging systems
in cervical cancer patients and their impact on survival
outcomes. The secondary endpoints were identifying prognostic factors for survival. This retrospective
study was conducted in compliance with the principles
of Helsinki Declaration and informed consent was
obtained from each patient. Ethical approval was not
obtained from the Institutional Review Board for this
retrospective study.
The patients with pathological stage IIIC disease were
categorized according to the number of LN metastasis
(1 vs. ≥2) and metastatic LN ratio (MLNR) (1-5%,
6-9% and ≥10%). MLNR was determined as [number
of metastatic LNs/the total number of dissected LNs]
×100. Although published studies used 10% as cutoff
value for MLNR (1-9% and ≥10%), we used three-tier
system using a cutoff value of 5% (1-5%, 6-9% and
≥10%).[
While adjuvant RCT was applied to patients with highrisk
factors (LN metastases, positive/close surgical
margins, and/or parametrial involvement), adjuvant
RT was applied to patients with intermediate-risk factors
(lymphovascular space involvement [LVSI], tumor
≥4 cm, and deep stromal invasion [DSI]).[
The key components of follow-up included gynecological
examination and laboratory tests every 3 months
for the first 2 years, every 6 months for the following 3
years, and annually thereafter. Imaging modalities and
PAP smear were performed when needed. Local and
distant recurrences were evaluated using computed tomography,
magnetic resonance, or positron-emission
tomography imaging.
The statistical analysis was performed using IBM Statistical
Package for the Social Sciences (SPSS) version
24. Kaplan-Meier method was used for survival analysis.
Overall survival (OS), progression-free survival
(PFS), local recurrence-free survival (LRFS), diseasespecific
survival (DSS), and distant metastasis-free survival
(DMFS) were calculated. All time related events
were calculated from the date of surgery to the past
follow-up, death, or recurrence, whichever came first.
Differences in survival rates according to FIGO 2009
and FIGO 2018 staging systems were compared using
the log-rank test. Multivariate cox regression model
was used to identify independent prognostic factors for
survival outcomes. P-value of <0.05 was considered as
statistically significant.
Pelvic and para-aortic LND, pelvic LND alone, and pelvic sampling were performed in 328 (57.4%), 138 (24.2%), and 34 (6%) patients, respectively. The mean number of dissected pelvic and para-aortic LN (sampling/ LND) was 23 (range, 1-101) and 6 (range, 1-54), respectively.
RT consisted of external RT and VCB in 387 (67.8%), external RT alone in 179 (31.3%), and VCB alone in 5 (0.9%) patients. Three hundred and twenty- two (56.4%) patients received concomittant cisplatin and 72% of them received at least four cycles. The median total dose of external RT was 45 Gy (range, 45?59.4 Gy). Doses and fractionations of VCB varied based on institutional preferences and from most frequent to the lesser were as follows: 3×500 cGy, 3×600 cGy, 2×650 cGy, 5×500 cGy, and 4×700 cGy.
FIGO Stage Migration
Stage migration was recorded in 401 (70.2%) patients.
The most remarkable stage migration was detected in
343 (60%) stage I patients. Migration to stage I was detected in 244 (42.7%) patients: 2 (0.4%) patients from
stage IA2 to IB1, 134 (23.4%) patients from stage IB1
to IB2, and 108 (18.9%) patients from stage IB2 to IB3.
Migration to stage IIIC1 due to the presence of
pelvic LN metastases was observed in 1 patient in stage
IA2, 54 patients in stage IB1, 33 patients in stage IB2, 23
patients in stage IIA, 15 patients in stage IIB, one patient
in stage IIIA, and eight patients in stage IIIB according
to FIGO 2009. Overall, 88 (15.4%) patients from stage
I, 38 (6.6%) patients from stage II, and 9 (1.6%) patients
from stage IIIA/B were upstaged to stage IIIC1 (Fig.
FIGO: Federation of Gynecology and Obstetrics.
Migration to stage IIIC2 due to the presence of the
para-aortic LN metastasis was recorded in six patients
in stage IB1, five patients in stage IB2, one patient in
stage IIA, nine patients in stage IIB, and one patient in
stage IIIB. Overall, 11 (1.9%) patients from stage I, 10 (1.8%) patients from stage II, and 1 (0.2%) patient from
stage IIIB were upstaged to stage IIIC2 (Fig.
Due to the incompatibility of staging systems, stages of patients with stage IA1 and IVA did not change.
Follow-up and Survival Outcomes
The median follow-up time was 59 months (range,
3-228 months). Four hundred and fifty-four (79.5%)
patients were alive, and 430 (75.3%) of these were free
of disease at the time of analysis. While 89 (15.6%) patients
died due to cervix cancer, 28 (4.9%) died due to
other reasons during follow-up. Twenty-four patients
were alive with disease at their last follow-up: Eight
with pelvic wall recurrences, four with vaginal cuff recurrence,
and nine with distant metastasis, in whom
three of these had also local recurrence. The median
time to locoregional failure and distant metastasis was 15 months (range, 1-152 months) and 18 months
(range, 1-152 months), respectively.
Five-year OS, PFS, LRFS, DSS, and DMFS rates
were 81.1%, 77.7%, 87.9%, 84.3%, and 84.8%, respectively.
Survival rates of each stage according to both
FIGO 2009 and 2018 are shown in Table
Five-year PFS rates according to FIGO 2009 were
82.8% for IB1 and 77.5% for IB2 (p=0.036). The corresponding PFS rates in FIGO 2018 were 90.2% for IB1,
80.5% for IB2, and 80.1% for IB3 (p=0.189). Although
FIGO 2009 staging system significantly discriminates
stage IB1 from IB2 in terms of PFS, we could not find
any statistical difference among FIGO 2018 stage IB
subgroups in terms of both PFS and OS rates. However,
the 5-year OS and PFS rates for stage IB1 were
better than stage IB2 and IB3 in the current FIGO 2018
staging system (Fig.
FIGO: Federation of Gynecology and Obstetrics.
The major difference between the two staging systems in terms of determining the prognosis was for stage IIB disease. The 5-year OS, PFS, and DMFS rates in stage IIB disease according to the former 2009 staging system were 72.4%, 70.9%, and 81.2%, and it was 81.7%, 79%, and 89.7%, respectively, in the recent 2018 staging system.
Lymph Node (LN) Status and Survival Outcomes
In the recent FIGO 2018 staging system, 157 (27.5%)
patients were up-staged to stage IIIC; 135 (23.6%) patients
in stage IIIC1, 22 (3.9%) patients in stage IIIC2
including 4 (0.7%) patients with only para-aortic LN
metastasis, and 18 (3.2%) patients with pelvic and
para-aortic LN metastases.
When the patients without LN metastasis (n=414,
72.5%) were compared with patients in stage IIIC1 (n=135, 23.6%) and IIIC2 (n=22, 3.9%) disease, there
were significant differences in OS and PFS rates according
to LN status (Table
Nodal Staging
The median number of metastatic LNs was 2 (range,
1?73). Five-year OS and PFS rates were higher in patients
with one LN metastasis than those with ≥2 LN
metastases (85.5% versus 61.4%, p=0.015 and 81.3%
versus 59.5%, p=0.006, respectively) (Fig.
FIGO: Federation of Gynecology and Obstetrics; LN: Lymph node; PLN: The number of pelvic lymph node metastasis; PALN: The number
of paraaortic lymph node metastasis; MLNR: Metastatic lymph node ratio.
The median number of pelvic LN metastasis in patients
with stage IIIC1 disease was 2. Patients with pelvic
LN metastastes were divided into two groups according
to the number of LN metastases (PLN 1 and PLN ≥2). Five-year OS rates were similar between two groups;
however, 5-year PFS rates were lower in patients with
PLN ?2 compared to those with PLN1 (Fig.
The median number of metastatic LN in patients
with stage IIIC2 disease was 2. The patients with paraaortic
LN metastasis were divided into two groups
according to the number of LN metastases (PALN 1
and PALN ≥2). Five-year OS and PFS rates were significantly
lower in patients with PALN ≥2 compared to
those with PALN 1 (Fig.
The median value of MLNR in stage IIIC was 6%.
Five-year OS and PFS rates were significantly lower in
patients with a MLNR of ≥10% compared to those with
a MLNR of <10% (Table
When survival curves of FIGO 2009 and FIGO 2018
staging systems were visually compared, the difference
among the survival curves of all stages observed more
clearly in the FIGO 2018 staging system (Fig.
FIGO: International Federation of Gynecology and Obstetrics.
Other Prognostic Variables
Univariate analysis revealed that large tumor size (both
≥2 cm and ≥4 cm), presence of LVSI, and para-aortic LN metastases were unfavorable prognostic factors for
both OS and PFS. The presence of parametrial invasion
was also poor prognostic factor for OS. DSI also
affected PFS unfavorably (Tables
In multivariate analysis, the presence of LVSI and
LN status was independent poor prognostic factors for
both OS and PFS (Tables
We also showed prognostic importance of well
known factors such as LVSI, ≥4 cm tumor size related to PFS and OS in our analysis similar to the other
studies in the literature [
With the addition of LN metastasis to the current
staging system, so called early-stage patients with LN
metastasis in the former staging are defined as stage
IIIC now and RCT is the standard of care in these patients.
The prognosis of patients with metastatic LN
was poor due to higher rates of local recurrence and
distant metastases.[
In addition, not only the presence but also the prognostic
significance of the number of metastatic LNs in
cervical cancer has been investigated in several studies.
[
There are few articles in the literature regarding
prognostic importance of the number of metastatic
para-aortic LNs. Takeda et al. showed that presence of
common iliac or para-aortic LN metastasis was related
with poor survival.[
MLNR is associated with tumor burden of nodal
disease and previous studies showed that MLNR had prognostic value for many types of cancer such as
rectal cancer, breast cancer, and esophageal carcinoma.[
The comparison between FIGO 2009 and FIGO
2018 staging systems revealed a significant difference
in OS and PFS rates in the early stages due to upstaging
of patients with LN metastasis to stage IIIC. There
was no significant difference between stages according
to 2009 staging system and survival curves were
close to each other. As determined in the survival
graph, the difference between whole stages becomes
clearer in the current FIGO 2018 staging system. Furthermore,
the certain result is that all stages will have
improved outcomes. This could be interpreted as Will
Rogers phenomenon.
Despite having achieved prognostic accuracy, our
study has some limitations. With combining data from
seven institutions, the contribution of multiple surgeons, pathologists, and different surgical approaches
could be accepted as a limitation of the study. However,
this limitation could also be seen as strength, as it
makes our conclusions more general and increases the
available sample size. Second limitation of this study is
that the size of metastatic LNs. We also did not include
the presence of extracapsulary invasion in patients with
stage IIIC2 disease in this analysis. We are planning to
put these details in our further study and will try to
evaluate if these paramaters have prognostic value in
terms of OS, PFS, LRFS, and DMFS rates.
In conclusion, although FIGO 2018 staging system
includes main factors such as LN status and tumor size,
it still needs further prognostic factors that predict
both OS and DFS rates. As shown in our analysis, we
think that including the number of metastatic LNs and
MLNR in the next version of the FIGO staging system
will improve the accuracy of the staging system.
Peer-review: Externally peer-reviewed.
Conflict of Interest: All authors declared no conflict of interest.
Ethics Committee Approval: The study was approved by
the Ege University Faculty of Medicine Medical Research
Ethics Committee (no: 18-10.2T/36, date: 01/11/2018).
Financial Support: None declared.
Authorship contributions: Concept - S.A., F.Y., Z.Ö.;
Design - S.A., F.Y., Z.Ö.; Supervision - F.Y., Z.Ö.; Funding
- None; Materials - B.B., Ç.S.B.E., M.G., B.A.Y., S.Ö.,
Ş.A.E., Ş.B.G., İ.A.Ç., F.S., S.Y.S., K.İ., C.Ö., İ.Ş.; Data collection
and/or processing - B.B., Ç.S.B.E., M.G., B.A.Y.,
S.Ö., Ş.A.E., Ş.B.G., İ.A.Ç., F.S., S.Y.S., K.İ., C.Ö., İ.Ş.;
Data analysis and/or interpretation - S.A., B.B.; Literature
search - S.A., B.B.; Writing - S.A., B.B., Ç.S.B.E.; Critical
review - F.Y., Z.Ö.