Table 1

Pros and cons of the revised International Federation of Gynecology and Obstetrics (FIGO) 2018 cervical cancer staging system

FIGO 2009FIGO 2018Pros and cons
StageDescriptionStageDescription
I The carcinoma is strictly confined to the cervix Pros
Clarity on depth of invasion and the relationship between the depth of stromal invasion and incidence of lymph node metastases. Rate of positive nodes of 0.1–0.2%, 0.4–1.9%, and 2.1–7.6% for tumors with depth <1 mm, 1–3 mm, and 3.1–5 mm, respectively18 19
IAInvasive carcinoma diagnosed only by microscopy. Stromal invasion with a maximum depth of 5 mm measured from the base of the epithelium and
a horizontal spread of no more than 7 mm. Vascular space involvement, venous or lymphatic, does not affect classification
IAInvasive carcinoma that can be diagnosed only by microscopy, with maximum depth of invasion ≤5 mm*
IA1Measured stromal invasion of no more than 3 mm in depth and no more than 7 mm in horizontal spread IA1Measured stromal invasion ≤3 mm in depth There was limited guidance in previous FIGO staging systems (1995 and 2009) on measuring horizontal spread20 21 with no correlation of the tumor width and the risk of nodal metastases. Unifocal lesions are straightforward to measure but unclear if a lesion has multiple invasive foci, which can be as high as 25% of stage IA1 carcinomas,21 and can be located close together or far apart. There is lack of consensus on how measurement is to be performed (adding the maximum horizontal dimension or measuring individually) which can change disease stage from IA1 up to IB20–22
IA2Measured stromal invasion of more than 3 mm but no greater than 5 mm with a horizontal spread of no more than 7 mmIA2Measured stromal invasion >3 mm and ≤5 mm in depth
IBClinically visible lesion confined to the cervix or microscopic lesion greater than IA2IBInvasive carcinoma with measured deepest invasion >5 mm (greater than stage IA); lesion limited to the cervix uteri with size measured by maximum tumor diameter† Pros
The classification of stage IB tumors into three sub-stages improves the discriminatory ability for outcomes.23
On multivariable analysis, stage IB2 disease is independently associated with a nearly two-fold increased risk of cervical cancer mortality compared with stage IB1 disease (adjusted HR 1.98, 95% CI 1.62 to 2.41, p<0.001).24
Survival is significantly different between 2018 FIGO stage IB1 and IB2 disease, with a nearly two-fold increased risk in cervical cancer mortality in stage IB2 disease compared with IB1 disease.24
Five-year survival in the FIGO 2018 schema was 91.6% (95% CI 90.4% to 92.6%) for stage IB1 tumors, 83.3% (95% CI 81.8% to 84.8%) for stage IB2 tumors, and 76.1% (95% CI 74.3% to 77.8%) for IB3 23tumors
Cons
Current staging still provides no clarification as to how tumor size should be measured either microscopically or grossly. This is particularly so for specimen demonstrating microscopic tumor in the conization specimen and subsequent additional tumor in final hysterectomy specimen
IB1Clinically visible lesion no more than 4 cm in greatest dimensionIB1Invasive carcinoma >5 mm depth of stromal invasion and ≤2 cm in greatest dimension
IB2Clinically visible lesion more than 4 cm in greatest dimensionIB2Invasive carcinoma >2 cm and ≤4 cm in greatest dimension
IB3Invasive carcinoma >4 cm in greatest dimension
IIThe carcinoma invades beyond the uterus, but has not extended onto the lower third of the vagina or to the pelvic wall
IIATumor without parametrial invasionIIAInvolvement limited to the upper two-thirds of the vagina without parametrial invasion
IIA1Clinically visible lesion no more than 4 cm in greatest dimensionIIA1Invasive carcinoma ≤4 cm in greatest dimension
IIA2Clinically visible lesion larger than 4 cm in greatest dimensionIIA2Invasive carcinoma >4 cm in greatest dimension
IIBTumor with parametrial invasionIIBWith parametrial involvement but not up to the pelvic wall
IIITumor extends to pelvic wall and/ or involves lower third of vagina, and/or causes hydronephrosis or non-functioning kidneyIIIThe carcinoma involves the lower third of the vagina and/or extends to the pelvic wall and/or causes hydronephrosis or non-functioning kidney and/or involves pelvic and/or para-aortic lymph nodes Pros
Stage IIIC1 is independently associated with improved cause-specific survival compared with stage IIIB disease (adjusted HR 0.79, 95% CI 0.74 to 0.85, p<0.001).24
Stage IIIC1 has been found to have superior cervical cancer-specific survival compared with stage IIIA-B disease24
Some studies have found micrometastases to have negative impact on prognosis as macrometastases25 and thus should be considered as positive nodes
IIIATumor involves lower third of vagina, no extension to pelvic wallIIIACarcinoma involves the lower third of the vagina, with no extension to the pelvic wall
IIIBTumor extends to pelvic wall and/or causes hydronephrosis or non-functioning kidneyIIIBExtension to the pelvic wall and/or hydronephrosis or non-functioning kidney (unless known to be due to another cause)
IIIC Involvement of pelvic and/or para-aortic lymph nodes (including micrometastases)‡ irrespective of tumor size and extent (with r and p notations)§ Cons
The staging system fails to describe what is to be considered pelvic positive nodes as a positive parametrial node may potentially be consider as positive pelvic disease.
Survival of stage IIIC1 disease significantly differed based on T=stage (5 year rates: 74.8% for T1, 58.7% for T2, and 39.3% for T3) with a 35.3% difference in absolute survival (p<0.001)24
Survival in stage IIIC1 varies depending on local tumor factors. Stage IIIC1 cervical cancer is not homogenous, and local tumor factors remain salient prognostic factors in cervical cancer24
IIIC1 Pelvic lymph node metastasis only  Higher FIGO staging was not consistently associated with worse 5-year survival rates: stage IIIA (40.7%, 95 CI 37.1% to 44.3%), stage IIIB (41.4%, 95% CI 39.9% to 42.9%), stage IIIC1 (positive pelvic nodes) was 60.8% (95% CI 58.7% to 62.8%), and stage IIIC2 37.5% (95% CI 33.3% to 41.7%)23
IIIC2 Para-aortic lymph node metastasis‡  Classification of all women with positive lymph nodes into a single stage results in a very heterogeneous group of patients with highly variable survival rates23
 Positive lymph nodes negatively affect survival (IIIC1 HR 2.0, p<0.001, IIIC2 HR 3.9, p<0.001, IIIC1 HR 1.36, p<0.001, IIIC2 HR 2.14, p<0.001). The impact on survival varies by T stage with the greatest effect seen in stage T1B with IIIC2 disease (HR 5.38, p<0.001 vs HR 1.5, p=0.001 for IIIC1 disease)26
 Although no prognostic significance has been found for isolated tumor cells, the precise prognosis of low-volume metastases (isolated tumor cells and/or micrometastases) needs further evaluation.2514 Evidence suggests that micrometastasis and isolated tumor cells should be considered as positive nodes as most centers indicate adjuvant treatment13 14
IV Tumor has extended beyond the true pelvis or has involved (biopsy proven) the mucosa of the bladder or rectum (bullous edema does not permit a case to be allotted to stage IV)
IVATumor invades mucosa of bladder or rectum, and/or extends beyond true pelvis (bullous edema is not sufficient to classify a tumor as IVA)IVASpread to adjacent pelvic organs
IVBDistant metastasis (including peritoneal spread, involvement of supraclavicular, mediastinal, or para-aortic lymph nodes, lung, liver, or bone)IVBSpread to distant organs
  • *Imaging and pathology can be used, when available, to supplement clinical findings with respect to tumor size and extent, in all stages. Pathological findings superseded imaging and clinical findings.

  • †The involvement of vascular/lymphatic spaces should not change the staging. The lateral extent of the lesion is no longer considered.

  • ‡Isolated tumor cells do not change the stage, but their presence should be recorded.

  • §Adding notation of r (imaging) and p (pathology), to indicate the findings that are used to allocate the case to stage IIIC. For example, if imaging indicates pelvic lymph node metastasis, the stage allocation would be Stage IIIC1r; if confirmed by pathological findings, it would be Stage IIIC1p. The type of imaging modality or pathology technique used should always be documented. When in doubt, the lower staging should be assigned.