3578 - Comparing the Effects of Paclitaxel Liposomes and Albumin-Bound Paclitaxel on the Tumor Regression Rate among Cervical Cancer Patients Undergoing Concurrent Radiotherapy

C. Wang, M. Cai, S. Liu, J. Chen, X. Sun, C. Ji, J. Wang, Y. Liang, J. Pan, J. Qiao, Y. Zhou, L. Chen, and J. Ma; Department of Radiation Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an Jiaotong University, Xian, China

Purpose/Objective(s): Radical radiotherapy represents the cornerstone of treatment for locally advanced cervical cancer, with the established effective chemotherapy regimen being the combination of paclitaxel and platinum-based agents. Nonetheless, variations exist in the rates of local control among patients undergoing concurrent chemoradiotherapy (CCRT). The purpose of this study was to focus on comparing the difference in tumor regression rates between patients receiving paclitaxel liposomal versus albumin-conjugated paclitaxel therapy for cervical cancer through imaging analysis of patients undergoing radical radiotherapy for locally advanced cervical cancer. Materials/

Methods: We retrospectively included 189 patients with locally advanced cervical cancer who received synchronized radiotherapy from January 2019 to December 2020 at our institution. They were divided into test and control groups, with albumin-conjugated paclitaxel at a dose of 135 mg/m² per dose in the test group and paclitaxel liposome at a dose of 135 mg/m² per dose in the control group. Both groups were treated with carboplatin or cisplatin in combination. And all these patients underwent magnetic resonance imaging before and during the treatment; The second MRI is usually performed prior to after loading radiotherapy and is roughly 40Gy-44Gy of radiation treatment. Tumor areas were mapped in MRI images using ITK-SNAP, image features were extracted, and the tumor regression rate was calculated and obtained.
Results: A total of 189 patients were included. 99 (52%) received liposomal paclitaxel, and 90 (48%) received albumin-bound paclitaxel. The pathologic staging was squamous cell carcinoma in both groups. The albumin-conjugated paclitaxel group was older (median 54 vs. 51 years, p = 0.897), and there were 64 patients (71.11%) with elevated SCC in the experimental group and 66 patients (66.67%) in the control group, and the difference between the groups was not statistically significant by chi-square test p>0.05. In addition, there was no significant difference between the two groups in terms of median RT dose, FIGO stage, or number of lymph node metastases. The results showed that the use of albumin-conjugated paclitaxel significantly increased the rate of tumor volume regression at this dose level (p<0.02). After external radiation at approximately 40–44Gy, the tumor regression rate was 64.8% (range 10.2–100%) in the experimental group, which was significantly higher than that of the control group at 51.6% (range 7.4–100%).
Conclusion: In patients with cervical cancer treated with CCRT, albumin-conjugated paclitaxel achieves a more favorable rate of local control compared with the use of paclitaxel liposomes, but more adverse effects, which were mainly characterized by grade 1 or 2 sensory neuropathy. Referring to the instructions for albumin-bound paclitaxel, it is recommended to be given 260mg/m², and we still got good tumor regression rate at a safer dose with controllable adverse reactions.