Effect of cisplatin cycles on prognosis for cervical cancer patients treated with concurrent chemoradiotherapy: a long-term cohort study

Purpose To assess the impact of cisplatin cycles on overall survival (OS) and disease-free survival (DFS) in cervical cancer (CC) patients undergoing concurrent chemoradiotherapy (CCRT), and to build a nomogram-based prognostic stratification to identify CC patients who might benefit from ≥ 5 cycles of cisplatin. Methods 918 patients were treated with external beam radiotherapy and brachytherapy. Weekly cisplatin was the concurrent regimen. The difference in survival outcomes between the < 5 cycles and ≥ 5 cycles groups were compared. Subgroup analysis was further conducted. Univariate and multivariate Cox regression analyses were performed in the < 5 cycles, and a nomogram was developed accordingly. The patients were divided into two risk subgroups and the survival outcomes were compared. Results The 5-year OS and DFS were 76.7% and 86.1% ( p  = 0.002), 68.7% and 78.3% ( p  = 0.0016) for the < 5 and ≥ 5 cycles, respectively. In subgroup analysis, the survival benefit of ≥ 5 cycles could be maintained in patients with > 50 years old, squamous disease, squamous cell carcinoma antigen (SCC Ag) > 1.5 ng/mL, tumor size > 4 cm, FIGO stage I/II, and no para-aortic metastatic lymph nodes. A nomogram incorporating size, SCC Ag, and stage was constructed, and patients were divided into two risk groups (low-risk and high-risk). Receiving ≥ 5 cycles showed superiority in OS ( p  = 0.0025) and DFS ( p  = 0.008) over < 5 cycles in the low-risk subgroup. Conclusion Receiving ≥ 5 cycles of cisplatin improved OS and DFS in patients with CC who received CCRT. A nomogram was constructed and the newly defined low-risk patients might gain significant OS and DFS benefit from receiving ≥ 5 cycles.