The Effect of Neoadjuvant Chemotherapy on Lymph Node Metastasis of FIGO Stage IB1-IIB Cervical Cancer: A Systematic Review and Meta-Analysis

OBJECTIVES: This study aimed to assess the effect of neoadjuvant chemotherapy (NACT) on the rate of lymph node metastasis (LNM) in FIGO stage IB1-IIB cervical cancer patients and compare the LNM between NACT plus surgery and surgery only. METHODS: We identified 34 eligible studies in PubMed, Web of Science, Cochrane Library, and EMBASE from inception to July 27, 2019. Data analyses were performed by Stata (version 13) and Revman (version 5.3). RESULTS: In these 34 included studies, the pooled incidence of LNM was estimated as 23% (95% CI, 0.20-0.26; I(2) = 79.6%, P<0.001). In the subgroup analysis, we identified five factors, including study type, year of publication, continents from which patients came, histological type and the FIGO stage. When taking FIGO stage into consideration, the LNM rate was 13% in stage IB (95% CI: 0.10-0.15; I(2) = 5.5%, P=0.385), 23% in stage IIA (95% CI: 0.18-0.28; I(2) = 0%, P=0.622), and 27% in stage IIB (95% CI: 0.20-0.33; I(2) = 0%, P=0.898), respectively. Through the comparison between NACT plus surgery and surgery only based on the six randomized controlled trials, the incidence of positive lymph nodes was lower in patients receiving NACT plus surgery than surgery only (RR=0.57, 95% CI: 0.39-0.83; I(2) = 60.5%, P=0.027). The 5-year OS was higher in the NACT + surgery group than surgery-only group (RR=1.13, 95% CI: 1.03-1.23; I(2) = 0.0%, P=0.842). CONCLUSIONS: Among cervical cancer in stage IB1-IIB, the preoperative NACT plus radical surgery resulted in a 23% probability of LNM, which was lower than those receiving radical surgery only. In stage IIA and IIB, the effect of NACT to reduce LNM was more obvious.