The safety of combining Endostar with concurrent chemoradiotherapy for the treatment of locally advanced cervical cancer and the evaluation of its anti-angiogenic effects via transrectal contrast-enhanced ultrasound.

Background: In recent years, exploring the addition of angiogenesis inhibitors to chemoradiotherapy for locally advanced cervical cancer (LACC) has gained research interest. This study assessed the safety and anti-angiogenic effects of combining Endostar with concurrent chemoradiotherapy (CCRT) via transrectal contrast-enhanced ultrasound.

Methods: A total of 120 patients with locally advanced cervical cancer (LACC) were randomly allocated to two groups: CCRT combined with Endostar (CRT+E group, n = 60) and CCRT alone (CRT group, n = 60). Endostar was administered intravenously before radiotherapy and repeated for four cycles. All patients received platinum-based CCRT. Adverse events were monitored, and transrectal contrast-enhanced ultrasonography (CEUS) was conducted before, during, and after radiotherapy. Vascular malformation (VM) rates were calculated from tumor cross-sectional images, and quantitative analysis software measured peak intensity (PI), time to peak (TTP), and mean transit time (MTT) of tumor vessels.

Results: No significant differences were observed in hematological, hepatic, renal, gastrointestinal, or cardiac adverse reactions between the two groups (all P>0.05). In the CRT+E group, VM rates, TTP, and MTT significantly differed at three time points (with P values of 0.003, 0.002, and P<0.001, respectively), whereas the CRT group showed no significant changes (all P>0.05). Post-radiotherapy, statistically significant differences emerged between the CRT+E and CRT groups for VM rates (P = 0.027), MTT (P = 0.027), and TTP (P < 0.001), while PI showed no significant difference (65.67 ± 36.53 vs. 74.69 ± 61.21, P = 0.598).

Conclusion: The combination of Endostar with CCRT for locally advanced cervical cancer (LACC) demonstrated favorable safety and tolerability. Transrectal contrast-enhanced ultrasound (CEUS) effectively assessed tumor vascular normalization induced by Endostar during CCRT. Specifically, Endostar significantly reduced VM rates and shortened MTT, suggesting its potential to normalize tumor vasculature.