Significance of histology and nodal status on the survival of women with early-stage cervical cancer: validation of the 2018 FIGO cervical cancer staging system

OBJECTIVE: To assess the efficacy of the FIGO 2018 classification system for nodal-specific classifications for early-stage cervical cancer; specifically, to examine the impact of nodal metastasis on survival and the effect of postoperative treatments, according to histological subtypes. METHODS: This society-based retrospective observational study in Japan examined 16,539 women with the 2009 FIGO stage IB1 cervical cancer who underwent primary surgical treatment from 2004 to 2015. Associations of cause-specific survival (CSS) with nodal metastasis and postoperative adjuvant therapy were examined according to histology type (squamous cell carcinoma [SCC], n=10,315; and non-SCC, n=6,224). RESULTS: The nodal metastasis rate for SCC was higher than that for non-SCC (10.7% vs. 8.3%, p<0.001). In multivariable analysis, the impact of nodal metastasis on CSS was greater for non-SCC tumors (adjusted-hazard ratio [HR], 3.11; 95% confidence interval [CI], 2.40–4.02) than for SCC tumors (adjusted-HR, 2.20; 95% CI, 1.70–2.84; p<0.001). Propensity score matching analysis showed significantly lower CSS rates for women with pelvic nodal metastasis from non-SCC tumors than from SCC tumors (5-year CSS rate, 75.4% vs. 90.3%, p<0.001). The CSS rates for women with nodal metastasis in SCC histology were similar between the postoperative concurrent chemoradiotherapy/radiotherapy and chemotherapy groups (89.2% vs. 86.1%, p=0.42), whereas those in non-SCC histology who received postoperative chemotherapy improved the CSS (74.1% vs. 67.7%, p=0.043). CONCLUSION: The node-specific staging system in the 2018 FIGO cervical cancer classification is applicable to both non-SCC tumors and SCC tumors; however, the prognostic significance of nodal metastases and efficacy of postoperative therapies vary according to histology.