Re-consideration of lymphadenectomy for stage Ib1 cervical cancer

Does the New FIGO 2018 Staging System Allow Better Prognostic Differentiation in Early Stage Cervical Cancer? A Dutch Nationwide Cohort Study

Simple Summary

The introduction of a revised staging system (FIGO 2018 staging system) for cervical cancer has led to a significant change in stage allocation for patients with early stage disease. It remains unclear how this change should be translated into treatment options, including less extensive surgery. With this Dutch national study we evaluated whether the revised staging system resulted in a more accurate prediction of overall and recurrence free survival compared to the previous FIGO 2009 staging system. In addition, we assessed other factors which may help the paradigm of treatment. We concluded that the revised FIGO 2018 staging system gives a more precise indication of survival outcomes of women with early stage cervical cancer. In addition, we believe that aside from stage, tumor characteristics, such as LVSI, and depth of invasion should be considered when offering patients less radical or less extensive treatment.

Abstract

The FIGO 2018 staging system was introduced to allow better prognostic differentiation in cervical cancer, causing considerable stage migration and affecting treatment options. We evaluated the accuracy of the FIGO 2018 staging in predicting recurrence free (RFS) and overall survival (OS) compared to FIGO 2009 staging in clinically early stage cervical cancer. We conducted a nationwide retrospective cohort study, including 2264 patients with preoperative FIGO (2009) IA1, IA2 and IB1 cervical cancer between 2007–2017. Kaplan–Meier analyses were used to assess survival outcomes. Logistic regression was used to assess risk factors for lymph node metastasis and parametrial invasion. Stage migration occurred in 48% (22% down-staged, 26% up-staged). Survival data of patients down-staged from IB to IA1/2 disease were comparable with FIGO 2009 IA1/2 and better than patients remaining stage IB1. LVSI, invasion depth and parametrial invasion were risk factors for lymph node metastases. LVSI, grade and age were associated with parametrial invasion. In conclusion, the FIGO 2018 staging system accurately reflects prognosis in early stage cervical cancer and is therefore more suitable than the FIGO 2009 staging. However subdivision in IA1 or IA2 based on presence or absence of LVSI instead of depth of invasion would have improved accuracy. For patients down-staged to IA1/2, less radical surgery seems appropriate, although LVSI and histology should be considered when determining the treatment plan.

Region-specific Risk Factors for Pelvic Lymph Node Metastasis in Patients with Stage IB1 Cervical Cancer

Objectives: We aimed to identify the risk factors associated with pelvic lymph node metastasis (LNM) at each anatomic location in patients with stage IB1 cervical cancer.

Methods: A primary cohort of 728 patients with stage IB1 cervical cancer who underwent radical hysterectomy and systematic pelvic lymphadenectomy were retrospectively studied. All removed pelvic nodes (N=20,134) were pathologically examined. The risk factors for LNM in different anatomic regions (obturator, internal iliac, external iliac, and common iliac) were evaluated by multivariate logistic regression analyses. Nomograms were generated from the primary cohort and validated in another external cohort (N=242). The performance of the nomogram was assessed by its calibration and discrimination. Overall survival and progression-free survival in patients with different LNM patterns were compared.

Results: LNM was found in 266 (1.3%) removed nodes and 106 (14.6%) patients. The incidences of LNM at the obturator, internal iliac, external iliac, common iliac, and parametrial regions were 8.5%, 5.4%, 4.7%, 1.9% and 1.8%, respectively. Among others, tumour size and lymph-vascular space invasion (LVSI), which are preoperatively assessable, were identified as independent risk factors of LNM in the common iliac region and the lower pelvis, respectively, and age was an additional independent risk factor of obturator LNM. The negative predictive values of tumour size <2 cm for common iliac LNM and negative LVSI combined with older age (> 50 years) for obturator LNM were 100% and 98.7%, respectively. A nomogram of these two factors showed good calibration and discrimination (concordance index, 0.761 in the primary cohort and 0.830 in validation cohort). The patients with common iliac LNM had poorer survival than those with LNM confined to the lower pelvis, while the differences in survival between patients with LNM confined to one node, one region or single side and those with more widely spreading LNM were not statistically significant.

Conclusions: Tumour size, LVSI and age are region-specific risk factors for pelvic LNM in IB1 cervical cancer, which could be used to allocate the appropriate extent of pelvic lymphadenectomy.

Cervical cancer with ≤5 mm depth of invasion and >7 mm horizontal spread - Is lymph node assessment only required in patients with LVSI?

OBJECTIVE

Cervical cancer with ≤5 mm depth of invasion and >7 mm horizontal spread is classified FIGO IA instead of FIGO IB in the revised staging system, as horizontal spread is no longer considered. We aimed to determine the incidence of lymph node metastasis (LNM) and, consequently, the necessity of pelvic lymph node assessment.

METHODS

Patients diagnosed between January 2015 and May 2019 with cervical cancer FIGO (2009) stage IB with ≤5 mm depth of invasion and >7 mm horizontal spread, were identified from the Netherlands Cancer Registry. Associations between disease-characteristics and lymph node metastasis (LNM), and overall survival, were assessed.

RESULTS

Of 170 patients, six (3.5%) had LNM: 4/53 (7.6%) with adenocarcinoma and 2/117 (1.7%) with squamous cell carcinoma (p = .077). Four-year overall survival was 98.2%. LNM was observed more often in tumours with LVSI (4/43 patients, 9.3%) than without LVSI (2/117 patients, 1.7%) (p = .045). In adenocarcinoma with 3-5 mm depth of invasion LNM rate was 10% (4/40). None of the following tumours were observed with LNM: squamous cell carcinoma without LVSI (0/74); adenocarcinoma with <3 mm depth of invasion (0/13); <3 mm depth of invasion without LVSI (0/36).

CONCLUSIONS

Lymph node assessment is essential in any tumour with LVSI or in adenocarcinoma with 3-5 mm depth of invasion. It can be omitted in squamous cell carcinoma without LVSI, in adenocarcinoma with <3 mm depth of invasion and in any tumours without LVSI and with <3 mm depth of invasion.

Prognostic significance of number of nodes removed in patients with node-negative early cervical cancer

AIM

The aim of this study was to investigate whether the number of removed lymph nodes was associated with survival of patients with node-negative early cervical cancer and to analyze the prognostic significance of clinical and pathologic features in these patients.

METHODS

Patients with FIGO stage IA-IIB cervical cancer who underwent radical hysterectomy with lymphadenectomy without receiving preoperative therapy were reviewed retrospectively. Patients were all proved to have lymph-node-negative disease and classified into five groups based on the number of nodes removed. The Kaplan-Meier method and Cox's proportional hazards regression model were used in prognostic analysis.

RESULTS

The final dataset included 359 patients: 45 (12.5%) patients had ≤10 nodes removed, 93 (25.9%) had 11-15, 98 (27.3%) had 16-20, 64 (17.8%) had 21-25, and 59 (16.4%) had >25 nodes removed. There was no association between the number of nodes removed and survival of patients with node-negative early cervical cancer (χ²  = 6.19, P = 0.185). Similarly, subgroup analyses for FIGO stage IB1-IIB also showed that the number of lymph nodes was not significantly related to survival in each stage. Multivariate analyses showed that histology and depth of invasion were independent prognostic factors for survival in these patients.

CONCLUSION

If a standardized lymphadenectomy is performed, the number of lymph nodes removed is not an independent prognostic factor for patients with node-negative early cervical cancer. Our study suggests that there is inconclusive evidence to support survival benefit of complete lymphadenectomy among these patients.