Comparative Analysis of Oncologic Outcomes in Patients with Squamous Cell Carcinoma of the Uterine Cervix with High-Risk Features for Para-Aortic Recurrence: Prophylactic Extended-Field versus Pelvic Chemoradiotherapy

Chung-Shih Chen,1 Yu-Ming Wang,1– 3 Eng-Yen Huang1– 3 1Department of Radiation Oncology & Proton and Radiation Therapy Center, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung City, 833, Taiwan; 2School of Traditional Chinese Medicine, Chang Gung University, Taoyuan, Taiwan; 3Department of Radiation Oncology, Kaohsiung Chang Gung Memorial Hospital, School of Medicine, College of Medicine, National Sun Yat-Sen University, Kaohsiung City, 804, TaiwanCorrespondence: Eng-Yen Huang, School of Medicine, College of Medicine, National Sun Yat-sen University, No. 70, Lienhai Rd, Kaohsiung, 80424, Taiwan, Email huangengyen@gmail.comPurpose: To compare the oncologic outcomes of prophylactic extended-field radiation therapy (EFRT) and whole pelvic radiation therapy (WPRT) in cervical patients at high risk of para-aortic lymph node (PALN) recurrence.Patients and Methods: From July 1999 to May 2022, a total of 115 patients with cervical cancer and high-risk features of PALN recurrence based on tumor markers, positive LNs and extensive parametrial invasion were retrospectively analyzed. All patients had received EFRT or WPRT at a dose of 39.6– 45 Gy and concurrent chemotherapy. In EFRT, coverage was extended to include the para-aortic region below the level of the left renal vein or T12.Results: Twenty-eight and 87 patients underwent EFRT and WPRT, respectively. For patients who survived, the median follow-up time was 60.8 months (range 9.2– 131.6 months) in the EFRT group and 115.9 months (range 16.9– 212.1 months) in the WPRT group. The 5-year overall survival (OS) and pelvic, extrapelvic and PALN recurrence rates were 87.7% vs 60.8% (p=0.019), 10.9% vs 25.3% (p=0.119), 18.1% vs 45.8% (p=0.011), and 0% vs 30.4% (p=0.005), respectively, between the EFRT and WPRT groups. Multivariate analysis revealed that EFRT and 2018 FIGO stage IV disease status were significant predictors of OS and extrapelvic recurrence.Conclusion: Compared to WPRT, EFRT significantly improved OS and reduced extrapelvic and PALN recurrence in patients with cervical cancer with high-risk recurrence features.Keywords: extended-field radiation therapy, cervical cancer, para-aortic recurrence, pelvic chemoradiotherapy