Objective The benefit of adjuvant chemotherapy after definitive chemoradiotherapy in patients with pelvic lymph node-positive cervical cancer has been poorly studied. This study aimed to test the hypothesis that the addition of adjuvant chemotherapy to definitive radiotherapy or concurrent chemoradiotherapy improves survival in patients with pelvic lymph node-positive cervical squamous cell carcinoma.

Methods This retrospective study enrolled patients with stage IB–IVA pelvic lymph node-positive cervical squamous cell carcinoma, without para-aortic lymph node metastases and initially treated with definitive radiotherapy or concurrent chemoradiotherapy between March 2007 and February 2018. Patients were classified into the adjuvant chemotherapy (5-fluorouracil or paclitaxel, plus cisplatin) and no-adjuvant chemotherapy groups. Treatment outcomes were compared between the two groups before and after 1:1 ratio propensity score matching.

Results Medical records of 951 patients were reviewed and 792 patients were excluded. Finally, 159 patients were enrolled for analysis. Of these, 42 patients received a median of two cycles (range, 1–6) of adjuvant chemotherapy and 117 patients under observation after primary treatment. The median follow-up period was 33.8 months (range, 2.9–113.0). Before propensity score matching, no significant difference was observed in survivals between the two groups (P>0.05). After propensity score matching, 37 pairs of patients were selected. The 3-year rates of progression-free survival, overall survival, local control, and distant metastasis-free survival in the adjuvant chemotherapy and no-adjuvant chemotherapy groups were 80.2% and 60.4% (P=0.07), 83.0% and 63.7% (P=0.17), 94.0% and 81.9% (P=0.12), and 85.9% and 60.1% (P=0.04), respectively. The incidences of grade 3–4 acute and late toxicities were comparable between the two groups (P>0.05).

Discussion Adjuvant chemotherapy significantly improved 3-year distant metastasis-free survival in patients with pelvic lymph node-positive cervical squamous cell carcinoma. Further prospective studies are needed to provide supportive evidence for the therapeutic efficacy of adjuvant chemotherapy.